Description of the P2P3 Backplanes ------------------------------------ Original Rev. 2-FEB-1995 Latest Rev. 27-JUL-1995 General Description This is a description of the P2 P3 Backplane for the Run II Trigger Frameworks. The P1 Backplane in these crates will be standard A16,A24 D8,D16 backplane. These Run II Framework crates are 21 slot crates that can hold 9U by 400mm cards. The P2P3 Backplanes use 160 pin 5 row connectors. The center row (C) is used for power and ground only. The outer pairs of rows (A/B and D/E) are pass through pins used to transport signals between the application cards and cables that plug into the backplane. Thus each application card has 128 pins on P2 and 128 pins on P3 for signal I/O. This provides enough I/O pins for 128 differential signals per application card. Two 64 conductor twist-flat cables can plug in through P2 and two more of these cables can plug in through P3. To protect against shorted power supplies the pins are cut down to a length that just protrudes through the backplane on the center row of the 5 row connectors. The (A/B and D/E) rows have shrouds over the pins both to protect these pins when connectors are plugged in and to provide protection for the power/ground pins. Power Supply Distribution Because these backplanes are being designed before all of the application cards have been fully defined, it is necessary to provide a lot of flexability in their power supply distribution. Providing lots of power supply distribution flexability is made somewhat difficult by the physical layout of the 3U high Eurocard backplanes. These 3U high backplanes only have space for two big Power Bars. Assuming that one of these Power Bars on both P2 and P3 backplanes will need to be the Ground Common Power Return connection this allows only one high current connection per backplane. We need to provide the following power supply voltages to the application cards. The current requirement estimates come from the tentative description of THE card. +5 Volts at 6.5 Amps per card +3 Volts at 16 Amps per card -2 Volts for ECL pull down terminator, at about 1.6 Amps per card -5.2 or -4.5 Volts for the ECL Translators, at about 1.2 Amps per card Reserve power distribution No. 1 ??? Reserve power distribution No. 2 ??? At this time it is not at all clear if we will use +5 Volts or +3.3 Volts for the FPGA's. The assumption is that we can use +3.3 Volts for the FPGA's. The following is the estimate of the total current required by 21 of THE Cards in a full crate. Total Crate Supply Current Watts of Voltage Required this Supply --------- ---------- ------------- +5.0 V 136.5 Amps 683 Watts +3.3 V 336 Amps 1109 Watts -2.0 V 33.6 Amps 68 Watts -4.5 V 25.2 Amps 114 Watts ------------- 1974 Watts total per crate There may also be a requirement for some other voltages. Reserve power distribution No. 1 ??? Reserve power distribution No. 2 ??? Power Supply connections to the P2-P3 backplanes ------------------------------------------------ --------------------------------+ O O O | <-- Backplane mounting hole | | <-- Space for one Power Bar or one +--+ +--+ +--+ | row of 10 point power taps | | | | | | | | | | | | | | | | | | | | | <-- Shroud on pins coming through the | | | | | | | back of the backplane | | | | | | | +--+ +--+ +--+ | Space for one Power Bar or one | <-- row of 10 point power taps | O O O | <-- Backplane mounting hole --------------------------------+ OK, so on a 3U P2-P3 backplane there is room for only one Power Bar or one row of 10 point power connectors between the backplane connector shrouds and the row of mounting holes that mount the backplane to the cardfile. OK, We Need to Make the P2-P3 a Single Monolithic Backplane ----------------------------------------------------------- The only way to cheat is to make the P2-P3 monolithic and then in the space at the interface between P2 and P3 where there is room for two rows of mounting screws one could alternate mounting screws with 10 point power connectors. Note that the 10 point power connectors do not go the whole way through the thick backplanes. With this monolithic P2-P3 one could have 4 Power Bars and about 21 of the 10 point power connectors. We could mount the 10-points sidewise between each set of shrouds on the TE160 connectors. How might we divide up these 10-points between the different power supplies that need them? 10-Point Backplane Slot Location Power Supply -------------- -------- ------------ 1 1 D Lower +5 V 2 2 U -2 V 3 3 D Upper +5 V 4 4 U -4.5 V 5 5 D Lower +5 V 6 6 U -2 V 7 7 D Upper +5 V 8 8 U -4.5 V 9 9 D Lower +5 V 10 10 U -2 V 11 11 D Upper +5 V 12 12 U -2 V 13 13 D Lower +5 V 14 14 U -4.5 V 15 15 D Upper +5 V 16 16 U -2 V 17 17 D Lower +5 V 18 18 U -4.5 V 19 19 D Upper +5 V 20 20 U -2 V 21 21 D Lower +5 V With this setup the loads on the 10-Point connectors would be something like: Power Current from Number of 10-Points Current Current Supply this Supply for this Power Supply per 10-Point per Via ------ ------------ --------------------- ------------ ------- +5 136 Amps 11 12.4 Amp/C 1.2 A/V -2 34 6 5.7 Amp/C 0.6 A/V -4.5 25 4 6.3 Amp/C 0.6 A/V Note that in principle about 1/3 of the +5 will go through the P1 backplane. This would bring the +5 current per 10-Point down to about 8 Amps. Note that the 10-Point connector is really called an AMP Power Tap. The type that we are interested in is an AMP # 55558-4 These are rated at 25 Amps per connector and 2.5 Amps per pin. The Power Bars for the +3V and Gnd connections are 3/8" x 3/8" copper bright tin plated with 3 copper studs. The copper studs are an M6 size. The bolts that connect the Power Bar to the backplane are an M3 size. How Would the Monolithic Backplane look? ---------------------------------------- --------------------------------+ O O O | <-- Backplane mounting holes ---------------------------+ | | | <-- Space for one Power Bar (Gnd ?) ---------------------------+ | +--+ +--+ +--+ | | | | | | | | | | | | | | | | | | | | | | <-- Shroud on pins coming through the | | | | | | | back of the backplane | | | | | | | +--+ +--+ +--+ | ---------------------------+ | | | <-- Space for one Power Bar (+3V ?) ---------------------------+ | O +----+ O | +----+ | | +----+ | <-- Backplane mounting holes alternate | | +----+ | | | <-- with 10-Point power connections. +----+ O +----+ | ---------------------------+ | | | <-- Space for one Power Bar (+3V ?) ---------------------------+ | +--+ +--+ +--+ | | | | | | | | | | | | | | | | | | | | | | <-- Shroud on pins coming through the | | | | | | | back of the backplane | | | | | | | +--+ +--+ +--+ | ---------------------------+ | | | <-- Space for one Power Bar (Gnd ?) ---------------------------+ | O O O | <-- Backplane mounting holes --------------------------------+ Do We gain Anything from the P1 Backplane ?? -------------------------------------------- What power connections do we get from a normal commercial 3U P1 backplane i.e. how many power pins connect to each application card: GROUND pins = 8 +5 Volt pins = 3 +12 Volt pins = 1 -12 Volt pins = 1 STDBY +5 Volt pins = 1 Adding a standard commercial VME-32 P2 back plane adds the following power pin connections to each application card: GROUND pins = 4 +5 Volt pins = 3 Thus the normal 6U VME-32 VME card has 12 Ground pins and 6 of the +5 Volt pins. At least this ratio sounds about correct. How to Assign the Power and Ground Pins in the Center Row of the Connecotrs ?? ------------------------------------------------------------------------------ The center rows of the two TE160 connectors give us 64 pins to work with. In addition we get some credit for the 3 +5 Volt pins on P1 and the 8 Grounds on P1. The expected per card currents are: +5 Volts at 6.5 Amps per card +3 Volts at 16 Amps per card -2 Volts for ECL pull down terminator, at about 1.6 Amps per card -5.2 or -4.5 Volts for the ECL Translators, at about 1.2 Amps per card Reserve power distribution No. 1 ??? Reserve power distribution No. 2 ??? Lets say that we want 15 pins for GND on each of P2 and P3. This leaves 17 pins for power on each of P2 and P3 plus the 3 pins that are +5 on P1. This is 35 pins total for power. There is a total of 25.3 Amps to get on card. Current for Fraction of Total Current Number of Pins Supply this Supply that is this Supply Assigned to this Supply ------ ----------- ------------------------- ---------------------- +5 6.5 25.7% 8.9 +3 16 63.2% 22.1 -2 1.6 6.3% 2.2 -4.5 1.2 4.7% 1.7 So this might result in a distribution across the connectors of something like Supply Pins P1 Pins P2 Pins P3 ------ ------- ------- ------- +5 3 3 3 +3 - 11 11 -2 - 2 1 -4.5 - 1 2 GND 8 15 15 With this setup we run about 1.4 Amps per pin worst case. Which Center Row Pins on P2 and P3 Carry Which Power Supply P2 Row C P3 Row C -------------- --------------- C1 Gnd-1 C1 Gnd-1 C2 +3V-1 C2 +3V-1 C3 Gnd-2 C3 Gnd-2 C4 +3V-2 C4 +3V-2 C5 -2V-1 C5 -4.5V-1 C6 Gnd-3 C6 Gnd-3 C7 +3V-3 C7 +3V-3 C8 Gnd-4 C8 Gnd-4 C9 +5V-1 C9 +5V-1 C10 Gnd-5 C10 Gnd-5 C11 +3V-4 C11 +3V-4 C12 Gnd-6 C12 Gnd-6 C13 +3V-5 C13 +3V-5 C14 Gnd-7 C14 Gnd-7 C15 -2V-2 C15 -4.5V-2 C16 Gnd-8 C16 Gnd-8 C17 +3V-6 C17 +3V-6 C18 Gnd-9 C18 Gnd-9 C19 +5V-2 C19 +5V-2 C20 +3V-7 C20 +3V-7 C21 Gnd-10 C21 Gnd-10 C22 +3V-8 C22 +3V-8 C23 Gnd-11 C23 Gnd-11 C24 -2V-3 C24 -4.5V-3 C25 Gnd-12 C25 Gnd-12 C26 +3V-9 C26 +3V-9 C27 Gnd-13 C27 Gnd-13 C28 +5V-3 C28 +5V-3 C29 +3V-10 C29 +3V-10 C30 Gnd-14 C30 Gnd-14 C31 +3V-11 C31 +3V-11 C32 Gnd-15 C32 Gnd-15 What Size Power Supply Brick Would We Use ?? -------------------------------------------- Power Current Brick Supply Required Size ------ --------- -------- +5 136 Amps 200 Amps +3 335 500 -2 34 50 -4.5 25 50 Note that limiting the -2 Volt and the -4.5 Volt supplies to 50 Amps helps with the safety requirements. What - How Many Layers Do We Make the P2-P3 Backplane ----------------------------------------------------- 1 Front "Component" Side Gnd Outer 2 -2,-4.5V 3 Gnd Inner 4 +3V 5 +5V 6 +3V 7 +5V 8 Back "Solder" Side Gnd Outer Split +3 Volt and +5 Volt Power Plane Layers -------------------------------------------- The +3 Volt planes are split into an upper section and a lower section. The upper +3 Volt Power Bar supplies the upper section of the +3 Volt planes which connect only to the P2 connectors (the upper connectors). The lower section of the +3 Volt planes is setup in a similar arrangement. The +5 Volt planes are split into an upper section and a lower section. The upper section of the +5 Volt planes are supplied by 5 of the 11 +5 Volt Ten-Point power taps and supplies only the P2 connectors (the upper connectors). The lower section of the +5 Volt planes is supplies by 6 of the 11 +5 Volt power taps and supplies only the lower P3 connectors. The reason for splitting the +3 Volt and the +5 Volt power planes is to give flexability in setting up the power distribution, especially if the required currents at the different voltage end up being different than what we currently forsee. How to Layout the "Pads" for the 10-Points and the Power Bars ------------------------------------------------------------- Ten-Point Pad Layout -------------------- On the both the front "component" side and the rear "solder" side of the backplane where the 10-Point connectors press in let's have trace at the potential of the 10-Point in the area of the 10-Point. This trace area will be under the 10-Point and will include the pads on the vias that the 10-Point plugs into. On both side the Solder Mask will cover all of this trace area except for the vias pads. For this 10-Point pad layout use 55 mil pads and have the trace area of the layout come tangent to the outer diameter of these pads. The purpose of these pads is to insure that all 10 vias are at the same potential and all are delivering power to the inner planes. Power Bar Pad Layout -------------------- In a close square pattern around the holes for the studs that hold on the Power Bars lets have 4 vias (of the standard hole size) that plat through the board and connect to the proper power planes. The distance along a side between these 4 vias is 0.250". On both sides of the board the solder mask covers this trace area except for a circle in the middle. On the front "component" side this area that is not covered with solder mask exposes a location for the head of the bolt that holds the Power Bar to connect to. On the rear "solder" side this area that is not covered with solder mask exposes a location for the washer that is between the Power Bar and the circuit board to connect to. The purpose of these pads is to insure that all Power Bar bolt hole and the 4 vias are at the same potential and all are delivering power to the inner planes. How Many Connectors and other Parts to Order -------------------------------------------- After verifying that the Erni 5 row connectors are the "good" stuff to use on this project, let's make one 2x order. This is especially true if we can get special straight pin male connectors with two lengths of pins (short "c"). Layout of Intergraph LEVELs in the P2P3.DGN File Rev. 5-APR-1995 ----------------------------------------------------------------------- Numb of LEVEL CONTENTS Elements ------- -------------------------------------------------------- -------- 1 Board Outline (this is a 97 mil width line-string). 1 LS It is drawn as 10 mils in the "board outling test plot". It is drawn as 100 mils in all other plots that require the Board Outline. 2 Board Mounting Holes drawn as 0.106" diameter. 63 Elps These are in 4 rows (bottom 21, 10, 11, 21 top). 3 - 4 Connector Mounting Holes drawn as 0.106" diameter. 84 Elps 5 Connector Pin Holes drawn as 0.040" diameter. 6720 Elps 6 Connector Location Text slot number, row abcde, 1&32. ? Txt 7 Outlines of Power Bars 0.375" square. ? ? 8 Trim Marks centered Outside of Board Outline. This is 8 LS 8 line-strings 0.050" outside the Board Outline. These are 100 mil line-strings. 9 Orientation and Index marks. 10 mil Line-strings. 4 LS 10 Label Board Outline Test Plot. 2 Txt 11 Label Layer #1 Component Side Ground Plane plot. 3 Txt 7 LS 12 Label Layer #2 +3 Volt Plane plot. 2 Txt 7 LS 13 Label Layer #3 +5 Volt Plane plot. 2 Txt 7 LS 14 Label Layer #4 -2 Volt Plane plot. 2 Txt 7 LS 15 Label Layer #5 -4.5 Volt Plane plot. 2 Txt 7 LS 16 Label Layer #6 +3 Volt Plane plot. 2 Txt 7 LS 17 Label Layer #7 +5 Volt Plane plot. 2 Txt 7 LS 18 Label Layer #8 Solder Side Ground Plane plot. 6 Txt 7 LS 19 Label Solder Mask plot. 2 Txt 20 Label Component Side Silkscreen plot. 2 Txt 21 Label Solder Side Silkscreen plot. 2 Txt 22 Text Char "A" for the Board Mounting Holes, see 63 Txt also Level 2. 23 Text Char "G" for the GND Power Bar Mounting Holes 40 "G" Txt See also: 50,51,52,60. 24 Text Char "B" for the Connector Mounting Holes. 84 Txt See also Level 4. 25 - 26 Component Side Silk Screen Text and 100 mil LineString. 397 Txt 62 LS 27 Solder Side Silk Screen Text and 100 mil line- 366 Txt strings (mirror image of). 126 LS 28 A line-string that separates the upper and lower 1 LS +5 Volt power planes. 40 mil line-strings. 29 A line-string that separates the upper and lower 6 LS +3 Volt power planes. 40 mil line-strings. 30 A line-string that separates the -2 Volt plane from 1 LS the -4.5 Volt plane. This is a 40 mil line-string. 31 Text Char "H" for the +3V Power Bar Mounting Holes 20 "H" Txt for P2 i.e. the upper +3V Power Bar. See also Levels: 53,54,55,61. 32 Text Char "K" for the +3V Power Bar Mounting Holes 20 "K" Txt for P3 i.e. the lower +3V Power Bar. See also Levels: 56,57,58,62. 33 Text Char "L" for the GND pins on the TE160 connectors. 630 Txt 34 Text Char "M" for the +5V pins on the TE160 connectors. 126 Txt 35 Text Char "N" for the +3V pins on the TE160 connectors. 462 Txt 36 Text Char "P" for the -2V pins on the TE160 connectors. 63 Txt 37 Text Char "R" for the -4.5 pins on the TE160 connectors. 63 Txt 38 Text Char "S" for row a,b,d,e pins on TE160 connectors. 5376 Txt 39 - 40 +5V Ten-Point layout: 0.040" pin hole diameter and 110 Elps line-string route boarder for exposed copper pad 11 LS directly under the 10-point 41 Text Char "C" for the pin holes for the +5V Ten-Points. 110 Txt 42 Line-string keep out boarder to separate the Gnd plane 11 LS from the +5V Ten-Point pads. 40 mil line-string. 43 -2V Ten-Point layout: 0.040" pin hole diameter and 60 Elps line-string route boarder for exposed copper pad 6 LS directly under the 10-point 44 Text Char "D" for the pin holes for the -2V Ten-Points. 60 Txt 45 Line-string keep out boarder to separate the GND plane 6 LS from the -2V Ten-Point pads. 40 mil line-string. 46 -4.5V Ten-Point layout: 0.040" pin hole diameter and 40 Elps line-string route boarder for exposed copper pad 4 LS directly under the 10-point 47 Text Char "E" for the pin holes for the -4.5V Ten-Points. 40 Txt 48 Line-string keep out boarder to separate the Gnd plane 4 LS from the -4.5V Ten-Point pads. 40 mil line-string. 49 - 50 GND Power Bar Mounting Pad Layout: mounting hole 40 Elps 0.120" diameter, 0.040 diameter vias, line-string 160 Elps route boarder for bare copper that surrounds the 40 LS mounting hole between the 4 vias. 51 - 52 Circle that represents a keep out boarder for the 40 Elps Inner Layers to keep the inner layer planes away from the GND Power Bar Mounting Hole. 53 Upper +3V Power Bar Mounting Pad Layout: mounting hole 20 Elps 0.120" diameter, 0.040 diameter vias, line-string 80 Elps route boarder for bare copper that surrounds the 20 Ls mounting hole between the 4 vias. 54 Line-string keep out boarder to separate the GND plane 20 LS from the Upper +3V Power Bar Mounting Pads. 40 mil line-string. 55 Circle that represents a keep out boarder for the 20 Elps Inner Layers to keep the inner layer planes away from the Upper +3V Power Bar Mounting Hole. 56 Lower +3V Power Bar Mounting Pad Layout: mounting hole 20 Elps 0.120" diameter, 0.040 diameter vias, line-string 80 Elps route boarder for bare copper that surrounds the 20 LS mounting hole between the 4 vias. 57 Line-string keep out boarder to separate the GND plane 20 LS from the Lower +3V Power Bar Mounting Pads. 40 mil line-string. 58 Circle that represents a keep out boarder for the 20 Elps Inner Layers to keep the inner layer planes away from the Lower +3V Power Bar Mounting Pads. 59 - 60 Text Char "W" for the 4 vias that are part of the 160 "W" Txt GND Power Bar mounting pad layout. See also: 23,50,51,52. 61 Text Char "X" for the 4 vias that are part of the 80 "X" Txt +3V Power Bar mounting pad layout for P2 i.e. the upper +3V Power Bar. 62 Text Char "Y" for the 4 vias that are part of the 80 "Y" Txt +3V Power Bar mounting pad layout for P3 i.e. the lower +3V Power Bar. 63 - Intergraph Text Character Usage Rev. 30-MAR-1995 ---------------------------------------------------- Text Pin Text Character Code Function Size Level --------- ---- ---------------------------------------- ------ ----- A 1 Board Mounting Holes 0.075" LV=22 B 2 Connector Housing Mounting Holes 0.075" LV=24 C 3 +5V Ten-Point layout pattern pin holes 0.050" LV=41 D 3 -2V Ten-Point layout pattern pin holes 0.050" LV=44 E 3 -4.5 Ten-Point layout pattern pin holes 0.050" LV=47 G 4 GND Power Bar Mounting Holes 0.075" LV=23 H 4 +3V upper Power Bar (P2) Mounting Holes 0.075" LV=31 K 4 +3V lower Power Bar (P3) Mounting Holes 0.075" LV=32 L 3 TE160 connector center row GND pins 0.050" LV=33 M 3 TE160 connector center row +5V pins 0.050" LV=34 N 3 TE160 connector center row +3V pins 0.050" LV=35 P 3 TE160 connector center row -2V pins 0.050" LV=36 R 3 TE160 connector center row -4.5V pins 0.050" LV=37 S 3 TE160 connector outer two rows each side 0.050" LV=38 W 3 Four Vias in the Mounting Pad Layout 0.075" LV=60 for the GND Power Bars X 3 Four Vias in the Mounting Pad Layout 0.075" LV=61 for the upper (i.e. P2) +3V Power Bar Y 3 Four Vias in the Mounting Pad Layout 0.075" LV=62 for the lower (i.e. P3) +3V Power Bar Text Characters in use for pins and holes: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z - - - - - - - - - - - - - - - - - ??? QUESTIONS ??? ------------------- 1. Can we fit in and work with 80 flat cables? 2. Is the Signal and Power Cable layout reasonable? 3 of #4 power 40 of Flat 64's signal 3 of #4 power 21 of #14 or #12 power 3 of #4 power 40 of Flat 64's signal 3 of #4 power 3. Do we have a reasonable estimate of the current from each power supply? 4. Can we flip the +5 and the +3 distribution if necessary? 5. Are the supplies: +5V, +3V, -2V, and -4.5V the proper supplies? 6. Do we need to have a reserved distribution net? 7. How should the various power supplies be distributed on the 32 pins of the center row of the TE160 connectors? Spread each supply along the connector helps to distribute it on the application card, but does it make it harder to route the application card. This is probably necessary because the power planes only contact the center row of pins through a mesh in the power plane. Keep the +3 pins or the Gnd pins just near the end of the connector where their power supply is makes for less drop in the backplane power plane between the Power Bar and the pins in the TE160. 8. What silk screen do we put on? 9. What pin text and what type of keep outs do I use. 10. What do we do about solder mask front and back. 11. How far back from the mounting surfaces do we keep the trace copper. 12. How do we go from the Intergraph files that exist to the files that we need to run the Intergraph BRD power plane generator software and the Gerber generator software ?? Need to get a written description of the BRD itself. Need to write the paper that will go to the BRD vendor. EDG moves us from the existing file to the files needed for generating the planes and Gerber. Positive or negative data? Do we flash things or draw things? Do we put Pads on all layers on all planes? Can we put the Gerber data on 3.5" floppies via Prospero? Need to finalize the hole sizes. 13. Text to identify the layers to the manufacturer and a window to see the layer markers. 14. Layer alignment marks. -._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._ Recipe to go from the DGN file to the GRB files. ------------------------------------------------ Rev. 3-APR-1995 File File Pos/Neg Nmbr Name File Contents Data ---- ---------- ----------------------------------- ------- 1. BrdOutLn.Grb TEST PLOT of just the board outline POS Levels = 1 Elements = Line-String ---> Draw D13 ! Draw the board outline with a 0.010" line. Levels = 8 Elements = Line-String ---> Draw D12 ! Draw the board trim marks with a 0.100 line. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 10 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. 2. Layer_1.Grb Layer 1 "Component Side" Ground Plane NEG Levels = 1 Elements = Line-String ---> Draw D14 ! Keep the plane back 50 mil from board boarder. Levels = 8 Elements = Line-String ---> Draw D12 ! Draw the board trim marks with a 0.100 line. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 11 Elements = LINE-String ---> Draw D12 ! Window in plane for layer identification, 0.100 line Levels = 11 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 22 Elements = TEXT Font = 0 Characters = A ---> Flash D26 ! Relieve Gnd plane around board mount holes. Levels = 24 Elements = TEXT Font = 0 Characters = B ---> Flash D22 ! Relieve Gnd plane around connector mount holes. Levels = 42 Elements = Line-String ---> Draw D11 ! Separate GND plane from +5V Ten-Point pad layout. Levels = 45 Elements = Line-String ---> Draw D11 ! Separate GND plane from -2V Ten-Point pad layout. Levels = 48 Elements = Line-String ---> Draw D11 ! Separate GND plane from -4.5V Ten-Point pad layout. Levels = 54 Elements = Line-String ---> Draw D11 ! Separate GND plane from top +3V Power Bar pad layout. Levels = 57 Elements = Line-String ---> Draw D11 ! Separate GND plane from bot +3V Power Bar pad layout. Levels = 34,35,36,37,38 Elements = TEXT Font = 0 Characters = M,N,P,R,S ---> Flash D30 ! Place pads and plane isolation donut on only ! connector pins nets +5V, +3V, -2V, -4.5V, & row abde. 3. Layer_2.Grb Layer 2 -2 Volt and -4.5 Volt Plane NEG Levels = 1 Elements = Line-String ---> Draw D14 ! Keep the plane back 50 mil from board boarder. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 12 Elements = LINE-String ---> Draw D12 ! Window in plane for layer identification, 0.100 line Levels = 12 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 22,24 Elements = TEXT Font = 0 Characters = A,B ---> Flash D22 ! Relieve plane around board & connector mount holes. Levels = 30 Elements = LINE-String ---> Draw D11 ! Draw line to separate -2V and -4.5V planes. Levels = 23,31,32 Elements = TEXT Font = 0 Characters = G,H,K ---> Flash D24 ! Relieve plane around GND Power Bar and +3V Power ! Bar mounting holes. Levels = 33,34,35,38,41,60,61,62 Elements = TEXT Font = 0 Characters = C,L,M,N,S,W,X,Y ---> Flash D30 ! Place pads and plane isolation donut on all ! nets EXCEPT -2 Volt and -4.5 Volt. 4. Layer_3.Grb Layer 3 Inner Ground Plane NEG Levels = 1 Elements = Line-String ---> Draw D14 ! Keep the plane back 50 mil from board boarder. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 13 Elements = LINE-String ---> Draw D12 ! Window in plane for layer identification, 0.100 line Levels = 13 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 22,24 Elements = TEXT Font = 0 Characters = A,B ---> Flash D22 ! Relieve plane around board & connector mount holes. Levels = 31,32 Elements = TEXT Font = 0 Characters = H,K ---> Flash D24 ! Relieve plane around and +3V Power Bar ! mounting holes. Levels = 34,35,36,37,38,41,44,47,61,62 Elements = TEXT Font = 0 Characters = C,D,E,M,N,P,R,S,X,Y ---> Flash D30 ! Place pads and plane isolation donuts on ALL ! pins except for the Ground net. 5. Layer_4.Grb Layer 4 +3 Volt Plane NEG Levels = 1 Elements = Line-String ---> Draw D14 ! Keep the plane back 50 mil from board boarder. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 14 Elements = LINE-String ---> Draw D12 ! Window in plane for layer identification, 0.100 line Levels = 14 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 22,24 Elements = TEXT Font = 0 Characters = A,B ---> Flash D22 ! Relieve plane around board & connector mount holes. Levels = 23 Elements = TEXT Font = 0 Characters = G ---> Flash D24 ! Relieve plane around GND Power Bar mounting holes. Levels = 29 Elements = LINE-String ---> Draw D11 ! Draw line to separate upper and lower +3V planes. Levels = 33,34,36,37,38,41,44,47,60 Elements = TEXT Font = 0 Characters = C,D,E,L,M,P,R,S,W ---> Flash D30 ! Place pads and plane isolation donut on all ! nets EXCEPT +3 Volt. 6. Layer_5.Grb Layer 5 +5 Volt Plane NEG Levels = 1 Elements = Line-String ---> Draw D14 ! Keep the plane back 50 mil from board boarder. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 15 Elements = LINE-String ---> Draw D12 ! Window in plane for layer identification, 0.100 line Levels = 15 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 22,24 Elements = TEXT Font = 0 Characters = A,B ---> Flash D22 ! Relieve plane around board & connector mount holes. Levels = 23,31,32 Elements = TEXT Font = 0 Characters = G,H,K ---> Flash D24 ! Relieve plane around GND Power Bar and +3V Power ! Bar mounting holes. Levels = 28 Elements = LINE-String ---> Draw D11 ! Draw line to separate upper and lower +5V planes. Levels = 33,35,36,37,38,44,47,60,61,62 Elements = TEXT Font = 0 Characters = D,E,L,N,P,R,S,W,X,Y ---> Flash D30 ! Place pads and plane isolation donut on all ! nets EXCEPT +5 Volt. 7. Layer_6.Grb Layer 6 +3 Volt Plane NEG Levels = 1 Elements = Line-String ---> Draw D14 ! Keep the plane back 50 mil from board boarder. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 16 Elements = LINE-String ---> Draw D12 ! Window in plane for layer identification, 0.100 line Levels = 16 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 22,24 Elements = TEXT Font = 0 Characters = A,B ---> Flash D22 ! Relieve plane around board & connector mount holes. Levels = 23 Elements = TEXT Font = 0 Characters = G ---> Flash D24 ! Relieve plane around GND Power Bar mounting holes. Levels = 29 Elements = LINE-String ---> Draw D11 ! Draw line to separate upper and lower +3V planes. Levels = 33,34,36,37,38,41,44,47,60 Elements = TEXT Font = 0 Characters = C,D,E,L,M,P,R,S,W ---> Flash D30 ! Place pads and plane isolation donut on all ! nets EXCEPT +3 Volt. 8. Layer_7.Grb Layer 7 +5 Volt Plane NEG Levels = 1 Elements = Line-String ---> Draw D14 ! Keep the plane back 50 mil from board boarder. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 17 Elements = LINE-String ---> Draw D12 ! Window in plane for layer identification, 0.100 line Levels = 17 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 22,24 Elements = TEXT Font = 0 Characters = A,B ---> Flash D22 ! Relieve plane around board & connector mount holes. Levels = 23,31,32 Elements = TEXT Font = 0 Characters = G,H,K ---> Flash D24 ! Relieve plane around GND Power Bar and +3V Power ! Bar mounting holes. Levels = 28 Elements = LINE-String ---> Draw D11 ! Draw line to separate upper and lower +5V planes. Levels = 33,35,36,37,38,44,47,60,61,62 Elements = TEXT Font = 0 Characters = D,E,L,N,P,R,S,W,X,Y ---> Flash D30 ! Place pads and plane isolation donut on all ! nets EXCEPT +5 Volt. 9. Layer_8.Grb Layer 8 "Solder Side" Ground Plane NEG Levels = 1 Elements = Line-String ---> Draw D14 ! Keep the plane back 50 mil from board boarder. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 18 Elements = LINE-String ---> Draw D12 ! Window in plane for layer identification, 0.100 line Levels = 18 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 22 Elements = TEXT Font = 0 Characters = A ---> Flash D26 ! Relieve Gnd plane around board mount holes. Levels = 24 Elements = TEXT Font = 0 Characters = B ---> Flash D22 ! Relieve Gnd plane around connector mount holes. Levels = 42 Elements = Line-String ---> Draw D11 ! Separate GND plane from +5V Ten-Point pad layout. Levels = 45 Elements = Line-String ---> Draw D11 ! Separate GND plane from -2V Ten-Point pad layout. Levels = 48 Elements = Line-String ---> Draw D11 ! Separate GND plane from -4.5V Ten-Point pad layout. Levels = 54 Elements = Line-String ---> Draw D11 ! Separate GND plane from top +3V Power Bar pad layout. Levels = 57 Elements = Line-String ---> Draw D11 ! Separate GND plane from bot +3V Power Bar pad layout. Levels = 34,35,36,37,38 Elements = TEXT Font = 0 Characters = M,N,P,R,S ---> Flash D30 ! Place pads and plane isolation donut on only ! connector pins nets +5V, +3V, -2V, -4.5V, & row abde. 10. SldrMask.Grb Solder Mask (the same for both sides) NEG Levels = 8 Elements = Line-String ---> Draw D12 ! Draw the board trim marks with a 0.100 line. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 19 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 22,24 Elements = TEXT Font = 0 Characters = A,B ---> Flash D23 ! Relieve solder mask around board & connector ! mount holes. Levels = 23,31,32 Elements = TEXT Font = 0 Characters = G,H,K ---> Flash D25 ! Relieve solder mask around GND Power Bar and +3V ! Power Bar mounting holes. Levels = 33,34,35,36,37,38,41,44,47 Elements = TEXT Font = 0 Characters = C,D,E,L,M,N,P,R,S ---> Flash D21 ! Relieve solder mask around all connector pins and ! Ten-Point vias but NOT around Power Bar pad vias. 11. CompSilk.Grb Silkscreen Component Side POS Levels = 8 Elements = Line-String ---> Draw D12 ! Draw the board trim marks with a 0.100 line. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 20 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 26 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the Component Side Silk Screen Text. Levels = 26 Elements = Line-String ---> Draw D12 ! Draw with 100 mil lines, rectangles of white ! silkscreen. 12. SldrSilk.Grb Silkscreen Solder Side POS Levels = 8 Elements = Line-String ---> Draw D12 ! Draw the board trim marks with a 0.100 line. Levels = 9 Elements = LINE-String ---> Draw D10 ! Draw layer orientation and index marks, 0.010 line. Levels = 21 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the layer identification text. Levels = 27 Elements = TEXT Font = 1 ---> Write Text D10 ! Write the Component Side Silk Screen Text. Levels = 27 Elements = Line-String ---> Draw D12 ! Draw with 100 mil lines, rectangles of white ! silkscreen. 13. Drill_1.Grb Drill file for mounting holes POS Levels = 22,24 Elements = TEXT Font = 0 Characters = A,B ---> Flash D20 14. Drill_2.Grb Drill file for Power Bar holes POS Levels = 23,31,32 Elements = TEXT Font = 0 Characters = G,H,K ---> Flash D20 15. Drill_3.Grb Drill file for connector pine and vias POS Levels = 33,34,35,36,37,38,,41,44,47,60,61,62 Elements = TEXT Font = 0 Characters = C,D,E,L,M,N,P,R,S,W,X,Y ---> Flash D20 -._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._ Bolts to mount the Power Bars to the P2P3 Backplanes ---------------------------------------------------- OK, the decision has been taken to use 4-40 x 3/4" self-clinching studs to hold the Power Bars onto the backplanes. So what are the dimensions of these studs: threaded section diameter 0.110" knerled section diameter 0.146" head diameter 0.175" It is obvious that there will be distortions in the backplane PCB as these self-clinching studs pull in. The internal planes will need to be relieved back from the holes for these studs. So what "D code" flashes need to be adjusted and what should their final size be? The current "up-dated" D code file, for us with the 4-40 studs, is in the next section which is document that goes to the PCB manufacture. The PCB manufacture document also has the up-to-date correct dimensions for the drill files for 4-40. -._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._ DATE: 9-JUNE-1995 TO: MULTEK INC. 16 Hammond St. Irvine, CA 92718 FROM: Daniel Edmunds Physics Department Michigan State University East Lansing, MI 48824-1116 RE: Manufacture of a Printed Circuit Boards called the P2P3 Revision A backplane. Michigan State University, Purchase Order Number 83744 Information for the Manufacture of the P2P3 Circuit Boards -------------------------------------------------------------- Rev. 9-JUNE-1995 This note describes the P2P3 circuit board and data files that we have supplied for manufacturing it. We are ordering a quantity of 15 of the P2P3 circuit boards. These are an 8 layer board that is designed to mount to EuroCard mechanics. The overall dimensions of this card are 10.368" by 16.744". All layers of this card contain only power and ground planes; there are no signal traces on this card. The data for manufacturing this card is supplied in 15 Gerber files. These files are on IBM/PC format 3.5" floppy disks. All data is given as Gerber files in ASCII format using English units with leading zero suppression and the data has 3 fractional digits. Some of these files are positive data and some of the files are negative data. Please provide us with copies of the Photo-Plots for our approval before starting the manufacture of these printed circuit boards. The following is a list of these files, their file name, file contents, sense of the data (positive or negative), and the apertures selected: P2P3 Circuit Board page 2 9-JUNE-95 P2P3 Circuit Board Design Files and Contents ------------------------------------------------ Data Apertures File Name File Contents Sense Selected ------------ ------------------------------------- ----- --------------- BrdOutLn.Grb TEST PLOT of just the board outline POS D10,D12,D13 Layer_1.Grb Layer 1 "Component Side" Ground Plane NEG D10,D11,D12,D14 D22,D26,D30 Layer_2.Grb Layer 2 -2 Volt, -4.5 Volt Plane NEG D10,D11,D12,D14 D22,D24,D30 Layer_3.Grb Layer 3 Inner Ground Plane NEG D10,D12,D14 D22,D24,D30 Layer_4.Grb Layer 4 +3 Volt Plane NEG D10,D11,D12,D14 D22,D24,D30 Layer_5.Grb Layer 5 +5 Volt Plane NEG D10,D11,D12,D14 D22,D24,D30 Layer_6.Grb Layer 6 +3 Volt Plane NEG D10,D11,D12,D14 D22,D24,D30 Layer_7.Grb Layer 7 +5 Volt Plane NEG D10,D11,D12,D14 D22,D24,D30 Layer_8.Grb Layer 8 "Solder Side" Ground Plane NEG D10,D11,D12,D14 D22,D26,D30 SldrMask.Grb Solder Mask (the same for both sides) NEG D10,D12 D21,D23,D25 CompSilk.Grb Silkscreen Component Side POS D10,D12 SldrSilk.Grb Silkscreen Solder Side POS D10,D12 Drill_1.Grb Drill file for mounting holes POS D20 Drill_2.Grb Drill file for Power Bar holes POS D20 Drill_3.Grb Drill file for connector pin and vias POS D20 P2P3 Circuit Board page 3 9-JUNE-95 The table below summarize the correspondence between the Gerber Draft Codes used and the apertures expected. D10 draw 0.010 inch wide line (used for text, and for the alignment and index marks) D11 draw 0.040 inch wide line (used for plane separation) D12 draw 0.100 inch wide line (used for trim marks) D13 draw 0.010 inch wide line (used for the board outline in the test plot only) D14 draw 0.100 inch wide line (used for outline to keep planes back from board border) D20 flash 0.010 inch diameter circle (used in drill files) D21 flash 0.060 inch diameter circle (holes in solder mask for pads) D22 flash 0.175 inch diameter circle (relieve inner planes around board mounting holes and the inner and outer planes around the connector mounting holes) D23 flash 0.150 inch diameter circle (relieve solder mask around board and connector mounting holes) D24 flash 0.200 inch diameter circle (relieve inner planes around Power Bar mounting holes) D25 flash 0.325 inch diameter circle (relieve solder mask around Power Bar mounting holes) D26 flash 0.225 inch diameter circle (relieve outer Gnd planes around board mounting holes) D30 flash donut Inner diameter 0.055 inch, Outer diameter 0.085 inch. Used to make a 55 mil pad isolated by a 15 mil ring from the surrounding power plane. P2P3 Circuit Board page 4 9-JUNE-95 This board uses three different hole types. The hole center locations for these holes are given in the last 3 Gerber format drill files. DESCRIPTION OF THE DRILL FILES --------------------------------- DRILL FILE NUMBER FUNCTION ----------------- -------------------------- DRILL FILE #1 These are the holes for mounting this board to the cardfile mechanics and for mounting the connector shrouds to the board. The finished size of these holes is 0.106" diameter. These holes are NOT plated. There are 147 of these holes. DRILL FILE #2 These are the holes for mounting the Power Bars to the board. The finished size of these holes is 0.123" diameter. All of these holes have pads on both sides of the board and ARE plated in the tunnel. There are 80 of these holes. DRILL FILE #3 These are the holes for connector press fit pins and other vias. The finished size after plating of these holes is 0.039" with a tolerance of + 0.003" / - 0.002" in diameter. All of these holes have pads on both sides of the board and ARE plated in the tunnel. There are 7,250 of these holes. -------------------------------------------------- ALL HOLE DIAMETERS ARE GIVEN AS THE FINISHED SIZE. -------------------------------------------------- P2P3 Circuit Board page 5 9-JUNE-95 ASSEMBLY OF THE BOARD Order of the Layers: ------------------------------------------- Component Side Silk Screen File: CompSilk.Grb Solder Mask (Same both sides) File: SldrMask.Grb Layer 1: "Component Side" Ground Plane File: Layer_1.Grb Layer 2: -2 Volt, -4.5 Volt Plane File: Layer_2.Grb Layer 3: Inner Ground Plane File: Layer_3.Grb Layer 4: +3 Volt Plane File: Layer_4.Grb Layer 5: +5 Volt Plane File: Layer_5.Grb Layer 6: +3 Volt Plane File: Layer_6.Grb Layer 7: +5 Volt Plane File: Layer_7.Grb Layer 8: "Solder Side" Ground Plane File: Layer_8.Grb Solder Mask (Same both sides) File: SldrMask.Grb Solder Side Silk Screen File: SldrSilk.Grb P2P3 Circuit Board page 6 9-JUNE-95 Data for Assembly of the P2P3 Printed Circuit Boards --------------------------------------------------------- Circuit board name: D-Zero Run II Framework P2P3 Backplane Rev. A ==== Reference Number: Michigan State University PO# 83744 Quantity: 15 P2P3 Rev. A Boards Circuit Board Material: G10, Between 0.125 and 0.160" TOTAL THICKNESS. 8 layers of 0.020" laminate should be fine with us. Please call to discuss the final board thickness before starting work on these cards. Solder Mask: Both Sides (The same solder mask is used on both sides.) Silk Screen: Both Sides (two different silkscreens) with white ink Tin plating: Only the area of copper NOT covered by the Solder Mask should be tin plated. Copper Weight: All layers (internal and external) should be of 2 oz. Board Trimming: TRIM MARKS have been provided on both outer copper layers of the printed circuit board and may be used as a guide during the routing process. Finished Board Size: Dimensions of this card are 10.368" by 16.744". Shipping: Please wrap each card individually to prevent damage during shipping. Ship to: DANIEL EDMUNDS 211 PHYSICS DEPARTMENT MICHIGAN STATE UNIVERSITY EAST LANSING, MI 48824-1116 PHONE: (517) 355-8525 FAX: (517) 355-6661 Billing: ACCOUNTS PAYABLE 366 ADMINISTRATION BUILDING MICHIGAN STATE UNIVERSITY EAST LANSING, MI 48824 -._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._ DATE: 25-APR-1995 RE: Manufacture / Purchase of quantity=15 of P2P3 Printed Circuit Boards Julie, This is an order for the manufacture of 15 printed circuit boards that we call the P2P3 Backplane. I estimate that the total cost of this P.O. will be about $16k so it will need to go out for a bid. I have the following companies to suggest as possible vendors. MULTEK INC. 16 Hammond St. Irvine, CA 92718 Phone: 714-951-3388 FAX: 714-951-5431 Kip Anderson Circuit Center Inc. 4738 Gateway Circle Dayton, Ohio 45440 Phone: 513-435-2131 Edie James Sovereign Circuits 12808 DeBartolo Drive North Jackson, OH 44451 Phone: (216) 538-3900 FAX: (216) 538-3820 or (216) 538-2434 Ron Bull As before with this type of order we will need to look at the bids when they come back and we will eventually need to know the P.O. Number that is assigned to this purchase. Thanks for taking care of this, Dan -._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._ Progress In Getting P2P3 Actually Manufactured. 1. Req for Supplies and go out for bids on 25-APRIL-95 2. Send floppy and instructions to Multek on 9-JUNE-95 3. Receive Customer Photo Plots from Multek on 21-JUNE-95 4. Call Multek on 22-JUNE-95 to talk about: There are no pads anywhere ! What version of the instructions are you working from? They had both the 25-APR and the 9-JUNE instructions out and people were working from both copies. I got them to throw away the 25-APR instructions. I told them that drill diameters had changed (finished hole sizes). They are going to photo plot again this time using the proper D30 and they will send us new photo plots. The engineer for this project is: Rudy Ruiz 714-951-3388 5. Receive new Photo Plots on the 23-June-95. It looks like they made up a layer 8 solder mask and put the wrong size mask outs on the board mounting holes. Try calling Rudy but he is not there. I leave a voice mail phone message. 6. Try calling Rudy on Monday the 26th but he is not there. Some one else says he will be there on Tuesday the 27th. 7. Call on the 27th and get Rudy. Talk about the wrong size mask out for board mounting holes on the solder mask that they made up and how the instructions talk about (in two places) using the same solder mask on both sides. Verify again they he has only the instruction from 9JUN95. Talk about board thickness and he says: between layers: 2-3, 4-5, 6-7, it is 20 mill material and all other layers are 17 mill (i.e. 1-2, 3-4, 5-6, 7-8). This gives 3x20 + 4x17 = 128 mil board thickness. 8. Received 13 of the 15 P2P3 circuit boards. So far in looking at them they look OK physically and mechanically. The only problem in the design that was spotted so far is the ten-point power taps will push through the card far enough that the tips of their pins will interfer with the plastic insulator the goes between the middle support bar and the backplane. Check hole sizes: Board Mounting - Connector Mounting #36 drill clears --> > 0.106" PEM studs for the Power Bars #31 drill clears --> > 0.120" #30 dril does not clear --> < 0.128" Connector Pin Holes, Ten-Point Pin Holes, Vias #60 drill clears --> >0.038" #59 dril does not clear --> < 0.041" -._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._.-._ Label of 10-Point Connections on the P2P3Backplane -------------------------------------------------------- Rev. 11-MAR-1998 Slot 21 Slot 1 vTT vEE vTT vEE vTT vTT vEE vTT vEE vTT +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ +-+ L+5 U+5 L+5 U+5 L+5 U+5 L+5 U+5 L+5 U+5 L+5 E A Vtt = -2.0 Volts = Yellow L+5 = Lower Vcc = +5.0 Volts Vee = -4.5 Volts = Orange U+5 = Upper Vcc = +5.0 Volts