IR Camera Power ------------------- Initial Rev. 14-SEPT-1996 Latest Rev. 11-JAN-1998 The first two section in this file are early engineering ESTIMATES of the power dissipation. Some of this information does NOT fit the final design. These sections have been retained because they do include some useful information. See the section near the end of this file for actual measured power consumption of the camera. A_Card Parts: 100324 -4.5V current 45 mA Typ. 70 mA Max. -2.0V current 114 mA Typ. 114 mA Max. +5.0V current 25 mA Typ. 38 mA Max. TCM2620 40 mW at 300 frames per second from 5V --> 8 mA Count half of this as analog and half as digital. 4 mA Typ. ADS-946 -5.0V current 120 mA Typ. 160 mA Max. +5.0V current 220 mA Typ. 270 mA Max. AD9631 -5.0V current 17 mA Typ. 21 mA Max. +6.0V current 17 mA Typ. 21 mA Max. Precision -5.0V current 5 mA Typ. 8 mA Max. Rail-Rail +6.0V current 5 mA Typ. 8 mA Max. OpAmp 74HCT541 +5.0V current 10 mA Typ. 15 mA Max. LM3x7 Standing Current 10 mA Typ. An A_Card Consists of: 100324 x4 ---> 736 mA Total Typ. TCM2620 x1 ---> 4 mA Total Typ. ADS-946 x1 ---> 340 mA Total Typ. AD9631 x1 ---> 17 mA Total Typ. Precs Rail-Rail OpAmp x2 ---> 5 mA Total Typ. 74HCT541 x2 ---> 20 mA Total Typ. LM3x7 x7 ---> + 70 mA Total Typ. ---------------------- Total 1,192 mA Total Typ. ---> 11.9 Watts D_Card Parts: 100325 -4.5V current 27 mA Typ. 37 mA Max. +5.0V current 45 mA Typ. 65 mA Max. TCM2620 40 mW at 300 frames per second from 5V --> 8 mA Count half of this as analog and half as digital. 4 mA Typ. 74HCT541 +5.0V current 10 mA Typ. 15 mA Max. LM3x7 Standing Current 10 mA Typ. A D_Card Consists of: 100325 x3 ---> 219 mA Total Typ. TCM2620 x1 ---> 4 mA Total Typ. 74HCT541 x3 ---> 30 mA Total Typ. LM3x7 x3 ---> + 30 mA Total Typ. ---------------------- Total 283 mA Total Typ. ---> 2.8 Watts Total power dissipated by the camera is: (4 x 11.9 W) + 2.8 W = 50.4 Watts This 50.4 Watt number assumes that the ECL 56 Ohm pull down resistors are part of the camera and that the supply to the camera is +- 10 Volts. If we remove the 56 Ohm pull down resistors from the camera then the current required by the 100324's changes from: 100324 -4.5V current 45 mA Typ. 70 mA Max. -2.0V current 114 mA Typ. 114 mA Max. +5.0V current 25 mA Typ. 38 mA Max. to: 100324 -4.5V current 45 mA Typ. 70 mA Max. +5.0V current 25 mA Typ. 38 mA Max. This reduces the power requirement of an A_Card to only 7.36 Watts. Now the total power dissipated by the camera is: (4 x 7.36 W) + 2.8 W = 32.2 Watts This 32.2 Watt number assumes that the 56 Ohm ECL pull down resistors are located at the receiving end in the VME environment and that the camera runs from +- 10 Volt supplies. Now the linear regulators do not really need a 5 Volt In-Out differential. They are rated to run with a 3 volt differential. So the whole camera could run from +- 8 Volts instead of the +- 10 Volts (except for the internal +6V supply). This would reduce to power requirement to 80% of the previous figure. Now the total power dissipated by the camera is: 32.2 Watts x 80% = 25.8 Watts The 25.8 Watt number assumes receiver end 56 Ohm pull down resistors and operation from +- 8 Volt supplies. *************************************************************************** Now calculate calculate the power dissipation under the following conditions: 1. All of the digital stuff runs off of "remote regulated, remote sensed" power supplies. These would need to be: +5V, -4.5V. 2. All of the analog stuff runs off of local linearly regulated supplies. These would need to be on the A_Card: +6V_A, +5V_A, +5V_D, -5V_A. The bulk power for these supplies is +10V and -10V. 3. The ECL 56 Ohm pull downs have been located at the receiving end to eliminate there contribution to the power dissipation in the box on the dewar. So now calculate this: Drawn from Average Camera Typ-Max Box x Supply A_Card Parts: Supply mWatt -------- ------- 100324 -4.5V current 45 mA Typ. 70 mA Max. -4.5V 259 -2.0V current 114 mA Typ. 114 mA Max. none 0 +5.0V current 25 mA Typ. 38 mA Max. +5V + 158 ----- total 417 TCM2620 40 mW at 300 frames per second from 5V --> 8 mA Count half of this as analog and half as digital. 4 mA Typ. +10V 40 ADS-946 -5.0V current 120 mA Typ. 160 mA Max. -10V 1400 +5.0V current 220 mA Typ. 270 mA Max. +10V 2450 ----- total 3850 AD9631 -5.0V current 17 mA Typ. 21 mA Max. -10V 190 +6.0V current 17 mA Typ. 21 mA Max. +10V 190 ----- total 380 Precision -5.0V current 5 mA Typ. 8 mA Max. -10V 65 Rail-Rail +6.0V current 5 mA Typ. 8 mA Max. +10V 65 OpAmp ----- total 130 74HCT541 +5.0V current 10 mA Typ. 15 mA Max. +5V 63 LM3x7 Standing Current 10 mA Typ. +10V 100 An A_Card Consists of: 100324 x4 ---> 1668 mW Total TCM2620 x1 ---> 40 mW Total ADS-946 x1 ---> 3850 mW Total AD9631 x1 ---> 380 mW Total Precs Rail-Rail OpAmp x2 ---> 260 mW Total 74HCT541 x2 ---> 126 mW Total LM3x7 x4 ---> + 400 mW Total ---------------------- Total 6,724 mW Total Typ. ---> 6.72 Watts per A_Card Drawn from Average Camera Typ-Max Box x Supply D_Card Parts: Supply mWatt -------- ------- 100325 -4.5V current 27 mA Typ. 37 mA Max. -4.5 V 144 +5.0V current 45 mA Typ. 65 mA Max. +5 V 275 ----- total 419 TCM2620 40 mW at 300 frames per second from 5V --> 8 mA Count half of this as analog and half as digital. 4 mA Typ. +10V 40 74HCT541 +5.0V current 10 mA Typ. 15 mA Max. +5V 63 A D_Card Consists of: 100325 x3 ---> 1257 mW Total TCM2620 x1 ---> 40 mW Total 74HCT541 x3 ---> 189 mW Total LM3x7 x1 ---> + 100 mW Total ---------------------- Total 1,586 mW Total Typ. ---> 1.59 Watts per A_Card Total power dissipated by the camera is: (4 x 6.72 W) + 1.59 W = 28.5 Watts +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Power Cable(s) from VME to Fast_IR_Camera FIRC ------------------------------------------------- We need to transport from the VME environment to FIRC the following voltages: +10V_A, +5V_D, -2.0V_D, -4.5V_D, -10V_A. These will be carried in two separate shielded cables: an Analog power cablel and a Digital power cable. The wiring of both cables is similar. Analog Power Cable Digital Power Cable Analog Power Cable and Digital Power Cable shields go to case ground. 22 gauge wire is about 1.65 Ohms per 100 feet +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ So the power supplies on the A_Card are: 1. +5 Volts Analog for the ADS-946 A to D converter 2. +5 Volts Digital for the ADS-946 A to D converter 3. -5 Volts Analog for the ADS-946 A to D converter and the AD9631 Op-Amp 4. +6 Volts Analog for the AD9631 Op-Amp 5. +5 Volts Analog for the TCM2620: AMPHI, COLHI, and ABAMPHI 6. +3.5 to 4.0 Volt Analog for the TCM2620 DSUB supply 7. +2.0 to 2.5 Volt Analog supply for the TCM2620 VCLAMP supply 8. +4.0 to 5.0 Volt Analog supply for the AC grounded end of the Op-Amp feedback circuit. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ In a September mail message Jeff Kuhn said, "I think we should worry about 40-50 watts. Our current electronics dissipate no more than 15-20 watts immediately outside of the dewar. I suggest we use an input and output air hose around the electronics box" +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Getting rid of the 56 Ohm pull down resistors at the camera end does save power at the camera end but it has the disadvantage of putting a low common mode impedance at the receiving end. This low common mode impedance at the receiving end will cause additional loop currents to circulate at the camera end. So we would like to move the ECL pull down back to the camera end. How much power does this cost if this all runs off of a remote regulated -2.0V supply ? There are 64 signals. Each signal has a non-inverted and inverted side. The nominal output levels are: -0.955 Volts and -1.705 Volts. So the -0.955 Volt state draws 18.66 mA through a 56 Ohm resistor and dissipates 19.5 mW of power in this resistor. And the -1.705 Volt state draws 5.27 mA through a 56 Ohm resistor and dissipates 1.55 mW of power in this resistor. So each of the 64 signals requires (18.66 mA + 5.27 mA = 23.93 mA) of current which is a total of 1.532 Amps of Vtt. And each of the 64 signals dissipates (19.5 mW + 1.55 mW = 21.05 mW) of power which is a total of 1.347 Watts in the pull down resistors. Conclusion: An additional 1.35 Watts at the camera end is the price of moving the pull down resistors into the camera. This would put the total camera power dissipation right at 30 Watts. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 16-SEPT-1997 Measure the power consumed by the camera (1x D-Card, 4x A-Card, 0x Array) at both 2 Mhz and 6 Mhz digitization rates. 6 Mhz -4.5V_D -2.0V_D +5.0V_D -9.0V_A +9.0V_A ------- ------- ------- ------- ------- Into Choke 4.476 V 2.049 4.975 8.979 8.980 Out From Choke 4.466 V 1.990 4.950 8.954 8.948 Brick Output 5.049 V 2.986 4.909 9.173 9.274 Amps 0.66 A 1.75 0.70 0.71 1.02 2 Mhz -4.5V_D -2.0V_D +5.0V_D -9.0V_A +9.0V_A ------- ------- ------- ------- ------- Into Choke 4.478 V 2.045 4.976 8.982 8.988 Out From Choke 4.468 V 1.983 4.950 8.957 8.956 Brick Output 5.102 V 3.028 4.782 9.131 9.382 Amps 0.66 A 1.75 0.66 0.71 1.00 The Choke input and output voltages are measured with respect to the M-Card Ground Plane. Voltage drop across the return chokes on the A-Card Digital Return Choke +47 mV Analog Return Choke -12 mV Power dissipated in the camera (assuming nominal supply voltages and measured currents) -4.5V_D -2.0V_D +5.0V_D -9.0V_A +9.0V_A ------- ------- ------- ------- ------- Volts 4.50 V 2.00 5.00 9.00 9.00 Amps 0.66 A 1.75 0.70 0.71 1.02 X ------- ------- ------- ------- ------- 2.97 W 3.50 3.50 6.39 9.18 \____________________________/ \________________/ 9.97 W Digital 15.57 W Analog \____________________________________________/ 25.54 W Total +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 29-DEC-1997 Tests of first official Analog Power Pan that uses the Astec made in China bricks. There are 2.2 uFd Tantalum capacitors across all of the Supply to Sense terminals. This new Analog power pan is connected to the Camera via 30 to 35 feet of Belden #9938 37 conductor 24 AWG cable. Check the supply voltages on the A-Card that is furthest from the M-Card power connector and compare this to the Analog Power Pan front panel tip jack voltages. Analog Power Pan A-Card Voltage Tip Jack Voltage -------------- ---------------- + 9.00 + 9.19 Volts - 9.00 - 9.25 + 5.00 + 4.96 - 4.51 - 5.06 - 2.012 - 2.955 The new first official Analog Power Pan appears to operate OK except the -2 V brick was oscillating at about 250 kHz at about 300 mV peak to peak. A 1500 uFd 16 Volt aluminum capacitor was put across the output of the -2 V brick and it quit oscillating. All sense leads are currently connected directly to the bricks, i.e. there are no series resistors in the sense leads yet. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 11-JAN-1998 Tests of supply voltages on the assembled system on the C130 on Friday 9-JAN-1998. Measurement Camera Analog on M-Card Power Pan or A-Card at Supply Test Points Location J1 ------ ------------- ------------ +9V 9.18 V 9.03 V -9V 9.26 9.04 +5V 4.98 5.02 -2V 2.932 2.010 -4.5V 5.04 4.53 VME Power Pan Supply Test Points ------ ------------- +5.0V 5.05 V +3.3V 3.324 -2.0V 2.044 -4.5V 4.55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 6-FEB-1998 Tests of supply voltages on the assembled system on the C130 on Friday 6-FEB-1998 after the Analog Supply had been adjusted for use with the 6.5V 1st stage reference voltage. 6-FEB-1998 11-JAN-1998 6-FEB-1998 Measurement Camera Analog Camera Analog on M-Card Power Pan Power Pan or A-Card at Supply Test Points Test Points Location J1 ------ ------------- ------------- ------------ +9V 9.18 V 9.69 V . V -9V 9.26 9.31 . NOT +5V 4.98 4.93 . CHECKED -2V 2.932 2.949 . -4.5V 5.04 5.05 .