Radiation Belt Storm Probes Electric Field and Waves Instrument Digital Fields Board Preliminary Design Review Wesley D. Cole (Hardware Design Engineer) Laboratory for Atmospheric and Space Physics University of Colorado at Boulder 3-4 Sept. 2008 EFW INST+SOC PDR

EFW-DFB Organization 3-4 Sept. 2008 EFW INST+SOC PDR

EFW Block Diagram You are here 3-4 Sept. 2008 EFW INST+SOC PDR

Electric Fields Requirements SOURCE REQUIREMENT EFW-45 Each EFW instrument shall perform interferometric timing measurements at high cadence using independent measurements from each of the paired probes, as follows: -- for waves of 0.1 mV/m to 300 mV/m, velocity range of 0 to 500 km/s in spin plane, and wave spatial scales of 0.1 to 30 km when inter-probe wave coherence is greater than 0.5 -- cadence: 16,384 samples per second -- sensitivity: 0.05 mV/m EFW-46 Each EFW instrument shall measure an electric field component perpendicular to the observatory spin axis (survey), as follows: -- frequency range: DC to 15 Hz -- magnitude range: 0 to 500 mV/m, at geocentric distances greater than 2.5 Re -- cadence: 32 vectors per second -- sensitivity: 0.3 mV/m or 10% for R > 3.5 Re, 3.0 mV/m for 2.5 Re < R < 3.5 Re EFW-48 Each EFW instrument shall measure low frequency AC electric field cross-spectra, as follows: -- frequency range: 10 Hz to 300 Hz -- magnitude range: 80 dB -- cadence: 6 seconds -- sensitivity: 1 x 10-12 V2/m2Hz at 30 Hz, 1 x 10-14 V2/m2Hz at 300 Hz EFW-49 Each EFW instrument shall measure an electric field component perpendicular to the observatory spin axis (burst), as follows: -- frequency range: DC to 300 Hz -- magnitude range: 0.3 to 500 mV/m -- cadence: 512 samples per second EFW-51 Each EFW instrument shall measure axial electric field components (survey), as follows: -- magnitude range: 2 mV/m to 500 mV/m -- sensitivity: 4 mV/m or 20% for R > 3.5 Re, 6 mV/m or 20% for 3.5 Re > R > 2.5 Re, 12 mV/m or 20% for R < 2.5 Re EFW-52 Each EFW instrument shall measure axial electric field components (burst), as follows: -- frequency range: DC to 256 Hz -- magnitude range: 0.4 to 500 mV/m -- sensitivity: 1 mV/m or 10% @ 50 Hz 3-4 Sept. 2008 EFW INST+SOC PDR

EMFISIS SCM and MAG Requirements SOURCE REQUIREMENT EFW-35 Each EFW instrument shall be capable of receiving 3D buffered analog search coil signals from the EMFISIS Waves instrument aboard its respective observatory, as follows: -- frequency range: 10 Hz to 300 Hz -- noise floor: < 1 x 10-8 nT2/Hz at 100 Hz -- dynamic range: 90 dB EFW-207 Each EFW instrument shall be capable of receiving DC-coupled, 3-axis data from the EMFISIS MAG instrument aboard its respective observatory, as follows: -- through an analog interface -- frequency range: from DC to 30 Hz -- noise floor: < 2 nTRMS -- dynamic range: 80 dB EFW-43 Each EFW instrument shall measure 3-D low frequency AC magnetic field cross-spectra, as follows: -- using the EMFISIS search coil signal -- magnitude range: 90 dB -- cadence: every 1 spin -- sensitivity: 1 x 10-8 nT2/Hz @ 100 Hz EFW-44 Each EFW instrument shall measure burst AC magnetic field, as follows: -- using EMFISIS search coil magnetometer data -- frequency range: 10 Hz to 250 Hz -- cadence: 512 samples per second -- sensitivity: 0.3 pT/Hz1/2 @ 100 Hz 3-4 Sept. 2008 EFW INST+SOC PDR

General Instrument Requirements SOURCE REQUIREMENT EFW-1 Each EFW instrument shall be designed for a total lifetime duration of 2 years plus 60 days. EFW-7 EFW-8 Each EFW instrument shall be capable of operating in an orbit with perigee altitude 500 km to 675 km (TBR) and apogee altitude 30,050 km to 31,250 km (TBR). Combined with the spacecraft charging model to determine the range of spacecraft potential: ± 225 V 7417-9019 ED&T 3.1.1 All parts used in RBSP observatory shall survive a total ionizing dose of 34 krad (Si) without parametric or functional failure. 7417-9019 ED&T 3.1.3.1 Parts susceptible to single event latch-up with linear energy transfer threshold less than 80 MeVsq cm/mg shall not be used in RBSP systems. 7417-9019 ED&T 3.1.3.2 SEUs in parts of non-critical systems shall not compromise flight system health or mission performance. Parts that may be susceptible to SEU shall be identified and submitted with the preliminary parts list to the APL RBSP Radiation Engineer for review. 7417-9019 ED&T 3.1.3.3 Hardware must operate through peak proton and electron flux. ED&T 3.2 Deep Dielectric Discharge: Parts, assemblies and components shall either have to survive discharge, be grounded with low enough impedance to prevent charging, or shield with enough material to reduce the total accumulated charge below discharge level. EFW-104 The EFW IDPU shall not exceed 10.37 kg. DFB allocation: 0.548 kg, per RBSP-EFW-SYS_003D_Mass EFW-63 Each EFW instrument shall not exceed the total power of 11.16 W from the EFW Main 28 V Service. DFB allocation: 1.8 W, per RBSP-EFW-SYS_004B_Power 3-4 Sept. 2008 EFW INST+SOC PDR

EFW – DFB Subsystem Performance Requirements Product Type Packet Name Source Signals (Internal to DFB) Measurement Range Measurement Resolution Driving Requirement Survey Waveforms E_SVY E12DC, E34DC, E56DC ± 1 V/m 30 uV/m EFW-45 V_SVY V1DC, V2DC, V3DC, V4DC ± 225 V 6 mV EFW-46 VAX_SVY V5DC, V6DC 0.5 V/m 5% EFW-51 Burst Waveforms E_B1 EFW-49 EFW-52 V_B1 V1DC, V2DC, V3DC, V4DC, V5DC, V6DC SCM_B1 SCM1, SCM2, SCM3 ± 5 V TBR EFW-44 E_B2 E12DC, E34DC, E56DC, E12AC, E34AC, E56AC, Epar, Eprp, EparAC, EprpAC AC: ± 200 mV/m DC: ± 1 V/m AC: 6 uV/m DC: 30 uV/m V_B2 V1AC, V2AC, V3AC, V4AC, V5AC, V6AC ± 10 V 0.3 mV SCM_B2 SCM1, SCM2, SCM3, SCMpar, SCMprp Wave Counter SOL1 Select 1 of: E12AC, E34AC 0.25 to 0.5, 0.5 to 1,..., 128 to 256 16 3-4 Sept. 2008 EFW INST+SOC PDR

EFW – DFB Interface Documentation DFB-IDPU Mechanical ICD (RBSP_IDP_MEC_200RevC) Digital Fields Board Specification (RBSP_EFW_DFB_001A_SPEC Rev A) AXB and SPB signals (Interface with BEB) Interface with DCB Interface with LVPS Interface through backplane EFW to EMFISIS Electrical Interface Control Document (RBSP_EFW_to_EMFISIS_ICD_revD.doc) SCM and MAG signals from EMFISIS 3-4 Sept. 2008 EFW INST+SOC PDR

EFW – DFB Resources Resource Current Best Est. Allocation Mass and Power Requirements Mass CBE based on THEMIS heritage board Power CBE based on analysis of current design and THEMIS heritage LVPS will supply power to DFB through the backplane ± 10 V (Analog) ± 5 V (Analog) + 5 V (Digital) + 3.6 V (Digital) + 1.8 V (Digital) Housekeeping Telemetry Requirements DFB produces no analog housekeeping FPGA diagnostic housekeeping sent to ground on request Commanded through DCB Resource Current Best Est. Allocation % Growth Margin Mass 0.438 kg (THEMIS) 0.548 kg 25% Power, Avg 1.4 W 1.8 W 28% Power, Peak 2.5 W 3-4 Sept. 2008 EFW INST+SOC PDR

DFB Block Diagram 3-4 Sept. 2008 EFW INST+SOC PDR

Radial and Axial Boom Signals Input signal range: ± 225 V Accuracy: 0.3 mV/m (for 100 m booms => 80 dB CMRR) Vishay 100-267T decade divider (1/100), Ratio tolerance: 0.01%, Input impedance: 1 MW, 300 V, 100 mW/resistor Same part used by THEMIS 3-4 Sept. 2008 EFW INST+SOC PDR

EMFISIS Signals and Differential Amp Gain accuracy: 80 dB, Resistor tolerance: 0.01% Vishay PHR or 300144Z foil resistors Deep dielectric discharge protection 3-4 Sept. 2008 EFW INST+SOC PDR

Active Filter Sallen-Key, 5-Pole, Low-Pass, Bessel, fc = 6.5 kHz Passband gain = 1, Linear phase and constant group delay (to preserve waveform shape in passband) Used 24 times in design 3-4 Sept. 2008 EFW INST+SOC PDR

Filter Test Results (Gain) 3-4 Sept. 2008 EFW INST+SOC PDR

Filter Test Results (Phase) 3-4 Sept. 2008 EFW INST+SOC PDR

NEW Filter Test Results (Square Wave) 3-4 Sept. 2008 EFW INST+SOC PDR

DFB Block Diagram 3-4 Sept. 2008 EFW INST+SOC PDR

Multiplexer Signal Lists Channel 1 Signals Channel 2 Signals V1DC V1AC V2DC V2AC V3DC V3AC V4DC V4AC V5DC V5AC V6DC V6AC E12DC FM1 E34DC FM2 E56DC FM3 E12AC SC1 E34AC SC2 E56AC SC3 Channel 1 signals meet the minimum science requirements 3-4 Sept. 2008 EFW INST+SOC PDR

DFB Block Diagram 3-4 Sept. 2008 EFW INST+SOC PDR

Analog to Digital Converter Linear Technology LTC1604AIG 16-bit parallel output, Sample rate: 333 ksps (256 ksps required) Successive approximation register with internal sample and hold Internal clock Internal reference (15 ppm/degree C) S/N ratio: 87 dB minimum, THD: -100 dB typical Integral linearity error: ± 2 LSB maximum Operating temperature range: - 40 degrees C to + 85 degrees C Manufactured on Mil-Spec line to Class S plastic specification Radiation tested, no latchup protection required Redundant cross-strapped design, either ADC can measure any signal Flown on THEMIS 3-4 Sept. 2008 EFW INST+SOC PDR

DFB Block Diagram 3-4 Sept. 2008 EFW INST+SOC PDR

FPGA and SRAM Actel RTAX2000SL Used for DSP functions, ADC and Mux control, SRAM interface and backplane interface 2,000,000 equivalent system gates Total ionizing dose: 300 krad 1.5 V core voltage, 3.3 V I/O voltage Honeywell HLX6228 Used for DSP scratchpad Organized as 128K word x 8-bit Static RAM 32 ns read/write cycle times Typical operating power: < 9 mW/MHz Total ionizing dose: 1,000 krad No latchup 3-4 Sept. 2008 EFW INST+SOC PDR

DFB Block Diagram 3-4 Sept. 2008 EFW INST+SOC PDR

Low Dropout Voltage Regulators MS Kennedy MSK 5922 K RH (1.5 V and 3.3 V) Total ionizing dose: 300 krad Backplane supply voltages: 1.8 V and 3.6 V Dropout voltage (from datasheet): 0.40 V max @ IOUT = 2.5 A Current manufacturer testing indicates a dropout voltage of only 0.15 V @ IOUT = 0.5 A MS Kennedy to add specification @ 0.5 A Contingency plans Raise backplane supply voltages to 1.9 V and 3.7 V Use Berkeley LDO design (THEMIS heritage) 3-4 Sept. 2008 EFW INST+SOC PDR

DFB Thermal Test Requirements REVISED Requirements imposed at the EFW IDPU to SC interface: +60°C Hot Survival Limit +55°C Hot Operational Test Limit -25°C Cold Operational Test Limit -30°C Cold Survival Limit 3-4 Sept. 2008 EFW INST+SOC PDR

Parts Parts Engineer: Cat Brant Parts procured or upscreened to EEE-INST-002 Level 2. Parts derated per EEE-INST-002 with additional derating as required for radiation sensitivity. Preliminary Identification List has been submitted to APL and has undergone review by Parts Control Board. Waiting for review by radiation group at APL. LTC1604AIG has been approved for screening, qualification and radiation. LASP is to write waiver because part latchup rating is < 80 MeV. No additional testing required assuming we get the JWST parts. LASP is participating in Actel FPGA common buy. LASP requests radiation testing and upscreening of AD648 and OP262 by APL. 3-4 Sept. 2008 EFW INST+SOC PDR

EFW DFB Testing Frequency response of analog filters Adjacent channel crosstalk Multiplexer switching ADC accuracy Test of each flight configuration Linear test of configurations not scheduled for flight use FPGA DSP testing Backplane interface test End-to-end test Thermal testing Pre-delivery testing 3-4 Sept. 2008 EFW INST+SOC PDR

DFB GSE Block Diagram 3-4 Sept. 2008 EFW INST+SOC PDR

Current Status DFB ETU analog section being assembled and tested FPGA testing to start in mid-September Long lead time parts identified One open item: MS Kennedy LDO voltage regulators 3-4 Sept. 2008 EFW INST+SOC PDR