Rad-hard 16-channel current driver has integrated decoder
To reduce the size of command and telemetry, Renesas Electronics has introduced the ISL72814SEH, a radiation-hardened 16-channel current driver with integrated 4-bit decoder. The driver integrates the decoder, input level shifter, and 16 current driver arrays in a single monolithic IC and is claimed to allow satellite manufacturers to significantly increase system capacity and reduce solution footprint by 50 per cent for their medium earth orbit (MEO), geosynchronous earth orbit (GEO), highly elliptical orbit (HEO), and deep space mission profiles.
Multiple ISL72814SEH current drivers are able to send 28V/500mA pulses for 750ms to the more than 1,500 RF switches in a communication satellite’s payload, routing RF signals to the designated internet radio stations and television channels. They also send 12 to 30V with 50 to 600mA latching pulses to control the relays and solenoids that turn on/off the propulsion system thrusters, change orbital altitude, and turn on the motor to tilt the solar panels. The ISL72814SEH offers twice the channel count and 54 per cent less VCE(SAT) power dissipation on each channel compared to competitive drivers, says Renesas. Its integrated level shifter removes several peripheral components, and its internal clamp diodes eliminate the need for additional protection circuitry when driving inductive loads.
The ISL72814SEH leverages Renesas’ proprietary silicon on insulator process to provide single-event effects (SEE) robustness in heavy ion environments. The driver’s integrated decoder interfaces directly to the general purpose I/Os of FPGAs and microprocessors in the satellite’s flight computer, to dramatically reduce pin count compared to one-input to one-output driver arrays. Each of the ISL72814SEH’s 16-channels of common-collector open-emitter PNP driver outputs can generate pulses of up to 42V and 700mA. The device is wafer acceptance tested to 100krad(Si) over high dose rate (HDR), and 75krad(Si) over low dose rate (LDR) total dose testing. Characterisation testing is completed with no single event latch-up (SEL), single event burnout (SEB), and single event transients (SETs) at a linear energy transfer (LET) of up to 86MeV.cm2/mg extended operating temperature range of -55 to +125 degrees C.
The ISL72814SEH can be combined with ISL71590SEH temperature sensor, ISL70591SEH precision current source, ISL71840SEH 30V 16-channel multiplexer, ISL70517SEH 36V differential input in-amp, ISL70419SEH precision op amp, ISL71090SEH12 precision voltage reference, and ISL72026BSEH CAN transceiver to create satellite command and telemetry signal processing.
The ISL72814SEH radiation-hardened 16-channel current driver is available now in a 28-lead ceramic flatpack package. An evaluation board is available to evaluate device features and performance.