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

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

EFW BLOCK DIAGRAM

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.

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

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.

BEB BLOCK DIAGRAM

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

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

BEB BIAS AC DISTORTION Vsphere = 26Vpp AC

BEB Bias, Usher, Guard Frequency Response

EWF to EMFISIS Buffer

BEB GROUNDING

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.

BEB ETU 1 BEB ETU Mass: 455 grams

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 4.1.1.1 BEB loading BEB input impedance at Vsphere >10G ohms 9 Preamp Signal 4.1.1.2 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

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

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

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.

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 7417-9098 REV B 6 BEB Test Specification RBSP_EFW_BEB_003 REV A

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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