Solar Probe Plus FIELDSInstrument PDRAntenna Electronics Box Selda S. Heavner U.C. Berkeley email@example.com
Agenda • Requirements & Specifications • Block Diagrams • Schematics • Layout • Mass and Power • Parts • Schedule • Issues
AEB Requirements • AEB Requirements • AEB shall provide ± 15V Floating Voltage to V1, V2, V3, V4 and V5 preamps (heritage RBSP) • Input is +5V Analog • Efficient >60% • Synchronized to 300KHz • Isolated secondary voltages • 5% output regulation • AEB shall regulate Preamp ±6 V from LNPS to ±5V • AEB shall provide the power and the control signal for the latching relay controls on the preamps (On V5 heater resistors) 3 bias impedances. • AEB shall be a nexus for MF and HF signals from preamp. The signals shall not have any traces on the board. The signals shall arrive on a DB connector and via coax cables (RG316). The signals shall be then connected to TDS, RFS and DFB (also DB connectors). • AEB shall provide housekeeping signals to DCB via multiplexer.
AEB Requirements AEB Specifications Cont. (heritage: THEMIS, RBSP) • Receive Preamplifier Signals • DC Voltage Level : ± 100V w.r.t chassis • Floating Ground Driver (heritage: THEMIS, RBSP) • AEB provides the reference source for each floating ground used by the Preamps • Input : PAn_LFOUT (preamp signal) • Input Filter: 300Hz • Output Voltage Level: ± 60VDC with respect to AGND • Output : References floating ground supply (± 15VDC)
AEB Requirements • BIASING VOLTAGES (V1-V4) AEB shall provide programmable biasing voltages to the V1-V4 preamps as follows: • BIAS (whip): ± 40 w.r.t preamp output • HEATSHIELD: ± 40 w.r.t preamp output • STUB: ± 40 w.r.t preamp output • BIASING VOLTAGES (V5) AEB shall provide a provide a programmable biasing voltage to the V5 preamp as follows: • BIAS (sensor): ± 40 w.r.t preamp output
AEB FLOATING POWER • AEB Breadboard Power Results • The supply is 68% when powered by 3.3V Digital at nominal load • The supply efficiency is expected to rise since MAX256 will be connected to 5V Analog from LNPS. • MAX 256 3W H-bridge driver • Has an internal oscillator so if SYNC signal is lost from DCB it will still run • Short circuit protection • Thermal shutdown • Used on RBSP, submitted to APL Jan 2013 for approval
LAYOUT and PARTS • LAYOUT • AEB ETU Layout started in October 2013. • Schematic will be finalized after peer review • MASS and POWER • ± 12V and ± 100V is now generated by LNPS. Helped mass. • Power updates are submitted to LNPS. No issues so far. • PARTS • MAX256 approval submitted to APL January 2013 • DAC121S101 has not been used on heritage designs. Submitted to APL and approved. 12-bit , low power • Multiplexer on AEB UT16MX110. • ISSUES • Connecting 12V to heater resistor on preamp (V5) • DAC needs to be at mid-scale when powered on. New DAC is at zero after power on reset.