1. Boom Electronics Board (BEB)
Jane Hoberman
University of California - Berkeley

2. BEB Review Outline Overall BEB design goals - Changes since PDR
- Reviews
Sub circuit design, performance requirements and verification:
- Floater Driver
- Bias, Usher and Guard Driver
- EFW/ Emfisis Buffer
- Ground Diagram
How well does the BEB meet it Specification?
- Power
- Mass
- Specification Table
- Parts (including Stress Analysis)
Status

3. EFW BLOCK DIAGRAM

4. BEB Design Drivers
- The Bias Drivers will provide current biasing of sensors.
- The Usher and Guard Drivers will provide voltage biasing of photoelectron control surfaces.
- The Floating Ground Driver will provide the reference source for each preamp ground, with a range of +/- 215 V with respect to SC ground.
- The BEB will provide “Bias”, “Guard”, & “Usher” programmable DC offset potentials with readback.
- The BEB will provide an AC test signal source to preamps.
- The EMFISIS buffer will deliver buffered, low-noise, analog, difference E-field signals to EMFISIS-WAVES from 10 Hz to 400 kHz.

5. New RBSP BEB Design Elements
BEB is based on CRRES, POLAR, and most recently, THEMIS heritage.
Changes from Themis BEB Design (no significant design changes since PDR):
+/-225 V output stage increased from +/-100 V, in order to increase Floating Ground and BIAS driver range.
- New High Voltage Transistors and Capacitors
- Increase in biasing range, thus rail-to-rail op amp required
- Layout for 480 V between some parts and traces
Floating Voltage increased to +/-15V from +/-10V
- change in some bypass capacitors
DAC commanding, and AC Test generation in DCB.
EMFISIS circuit added
- extra power and space requirements
- additional noise and frequency response requirement
Contingency operation without IDPU interface.
Removed from BEB: Actel, braid circuit, RTD

6. All concerns addressed. Peer design review 9/2/09. No issues.
BEB REVIEWS
PCB Layout Review 6/30/09
New PCB layout instituted the previously listed changes plus those below. PCB layout and schematic was reviewed .
All concerns addressed.
Peer design review 9/2/09. No issues.
Circuits additions since PDR:
Additional filtering for to reduce 200kHz line.
Insure no over voltage operation of floaters.

7. BEB BLOCK DIAGRAM

8. BEB Floating Ground Driver
Performance Requirements
Frequency Response: LP: 3 dB roll off at 300 Hz.
Output Dynamic Range: ± 215 Vdc wrt. SC GND.
Output: references Preamp floating power supply (±15Vdc wrt. FGND).
Opposing booms matched to 0.1% accuracy, DC to .5Hz.
Output level shall track Vsphere to at least .1% , from DC to.5Hz, 0V to 215V

9. BEB BIAS DRIVER Schematic almost identical to Guard, Usher driver
Performance Requirements
Frequency Response: LP: 3 dB roll off at 300 Hz.
Dynamic Range: ± 175 ± 40 (Vref) Vdc wrt. AGND, where full-scale DAC → Vref = ± 40 Vdc).
Opposing booms matched to 0.1% accuracy, DC to .5Hz (BIAS).
Gain of 1 with .1% tolerance. (Track Vsphere better than .1% from DC to .5Hz).
Noise Level: < 48 uVrms 10 to 10KHz; < 35 uVrms 10K to 400KHz
AC distortion < -40dB THD with +/-50VDC +/-100 Vp-p AC
DAC Resolution:1 nA
DAC Accuracy (BIAS): opposing booms matched to 0.1%
DAC step response: <25 ms

10. BEB BIAS AC DISTORTION
Vsphere = 26Vpp AC

11. BEB Bias, Usher, Guard Frequency Response

12. EWF to EMFISIS Buffer

13. BEB GROUNDING

14. BEB Power Table
Nom Voltage
+5V D
+10 V A
-10 V A
+225 V A
-225 V A
+/-15F1
+/-15F2
+/-15F3
+/-15F4
+/-15F5
+/-15F6
Nominal
Current (ma) 3
55*
50*
1.3**
.3**
1.8
Nom Power ( W)
.015
.55
.50
.2925
.0675
.054
Total nom power (W)
1.749
Peak Voltage
+10.5VA
-10.5VA
+240 V A
-240 V A
+/-17F1
+/-17F2
+/-17F3
+/-17F4
+/-17F5
+/-17F6
Peak Current (ma) 8
53*
6** 2
Peak Power (W)
.04
.5775
.5565
1.44
.072
.068
Total peak power (W)
3.094
* The maximum current of the +10V and -10V supplies are interdependent. The maximum current is dependent on the DAC setting.
** The maximum current of the +225V and -225V supplies are interdependent. The maximum current is dependent on the V sphere input.

15. BEB ETU 1
BEB ETU Mass: 455 grams

16. BEB Performance Compliance
specification
Specification Summary
Testing Done
Status 1
EFW-75: operation temp range
Temperature range -25 C to +55C
All parts comply
compliant 2
EFW-131: initial power On/Reset State
DAC comes up at mid range setting
Testing complete ETU 1 3
EFW-137
parts compliance
See next table 4
EFW- 57
isolated supplies for 4 SPB & 2Axial Preamps
By design 5
EFW-101
Contingency operating modes 6
Power 2.
Average power:1.75W
Peak power: 3.2W 7
Floating voltages 2.2
Floating voltages come up without DCB, DFB 8
Preamp Signal
BEB loading
BEB input impedance at Vsphere >10G ohms 9
Preamp Signal
Distortion
distortion to DFB increased
< -40dBV
Will be done 10
Floating Ground Driver 4.1.2
LP filter: 300 Hz 3db roll off
Output level shall track Vsphere to at least.1%, from DC to .5Hz, 0V to 215V
Compliant

17. BEB Performance Compliance (con’t)
specification
Specification Summary
Testing Done
Status 13
4.1.3 Bias/ Usher/ Guard Spec
HP filter: 300 Hz 3db roll off
Complete with ETU 1
compliant 14
DAC resolution better than 1nA (E-field) mode
calculated 15
DAC accuracy BIAS: better than .1% matching -40v to +40V on opposing booms 16
DAC accuracy Usher & GUARD: better than .5% matching -40v to +40V 17
Gain Matching (BIAS) better than .1% DC +/- 215 VDC 18
AC distortion <-40 dB THD with +/-50VDC +/- 100V p-p
Will be tested 19
Noise Floor:
10 Hz to 10KHz <48uVrms
10KHz to 400KHz <35uVrms
Excluding lines at multiples of 50KHz
Preliminary Test okay
Will tested in IDPU box with LVPS 21
4.1.4 ACTEST Output Spec 22
5 Commanding
AC test signal 23
DAc control 24
5 Command, 6 Analog Housekeeping
Analog Mux 25
DCB
Functional IDPU 8/15/09 26
LVPS 27
DFB

18. BEB EMFISIS Performance Compliance
specification
Specification Summary
Testing Done
Status 1
EFW-59
3 differential buffers
By design
compliant 2
EFW-102
EMFISIS will be powered without operational DCB, DFB
Testing complete ETU 1 3
EMFISIS spin plane sensor signals
Frequency response 10Hz to 400KHz
UCB & Iowa(8/21/09) 4
Sensitivity: 10Hz -12KHz:
3*10-14(V/m)2/Hz at 1KHz
Iowa Preliminary: noise floor -100db*
& meets requirement 5
Sensitivity: 10KHz -400KHz
3*10-17(V/m)2/Hz at 100KHz
Iowa Preliminary: 5% above requirement* 6
Max signal Amp:
50mV/m at 1KHz 7
Dynamic range:100,000 8
Output Impedance 20 ohms 9
EFW-208 EMFISIS axial plane sensor signals
Frequency response 10 to 400KHz
Not done
To be done** 10
Sensitivity: 10Hz -12KHz
3*10-15(V/m)2/Hz at 100Hz 11 12
30mV/m at 100KHz 13
Dynamic range:10,000 14 15
Mate with EMFISIS
Iowa (8/21/09)
*Includes room noise and EMFISIS instrument
**Not expected to be significantly different from Spin Plane test

19. BEB Parts and Quality assurance Compliance
PART NUMBER
PART TYPE
DERATING
Testing Required
STATUS 1
HA5127
OP AMP
Total Dose radiation
DC Passed 1/7/09
DDD
DC passed 10/2/08 2
AD5544
DAC
Single Event Upset
APL 3/18/09 3
AD648
DC passed 10/24/08 4
2SA1627
-600V PNP transistor
Power .6=.6W
Current .75=.75A
Voltage .75=-450V
Screened: EE-INST-002 section S1 table 2&3, derating table 4
Compliant
SPT5502TXV
700V NPN transistor
Power .6=3.6W
Voltage .75 =525V
EE-INST-002 section S1 table 4 5
AD822
Screened: EE-INST-002 section M3 table 2&3
In Process 6
M49467P07XXXJ
600V capacitors
.6 ceramic derating to 360V
EEE-INST-002 section C1 table 4 7
PCB layout
IPC-2221
PCB review 6/30/09 8
PCB board
FR4 4101/26 used
I-6012PC
Stress Calculations done on all parts. Spread sheet available.

20. BEB Summary of Documentation Status
Document Name
Number
Status
Date 1
BEB Schematic
RBSP_EFW_BEB_002 REV F
ETU Release
9/25/09 2
BEB Bill of Material 3
BEB Layout
RBSP_EFW_BEB_004 REV C
8/3/09 4
BEB Performance Specification
RBSP_EFW_BEB_001 REV G
pending 5
EFW to EMFISIS Interface
REV B 6
BEB Test Specification
RBSP_EFW_BEB_003 REV A

21. BEB: Test and Build Status
Finishing testing of ETU 2
- Complete verification of layout
- AC , and AC +DC distortion test
- Noise testing
2.Continue Functional Test of BEB with IDPU and Booms
- Axial Boom
- with 6 preamps
- noise characterization
3. EMFISIS Testing
- Axial plane test
4. Complete AD822 screening
5. Thermal testing for calibration purposes
6. Update ETU test plan for Flight

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