Rad Tolerant 3.3-V CAN Transceivers for Satellite Communications

Intersil Corp. recently announced  the industry’s first radiation-tolerant, 3.3-V controller area network (CAN) transceivers that are fully QML-V qualified and compliant with the ISO11898-2 physical layer standard. The three new ISL7202xSEH CAN transceivers provide reliable serial data transmission between a CAN controller and CAN bus at speeds up to 1 Mbps. Up to 120 of Intersil’s ISL7202xSEH transceivers can be connected to a single CAN bus to reduce cabling/harness size, weight and power (SWAP) costs. This weight and mass reduction of up to 18% allows system engineers to add millions of dollars in satellite functionality, and eliminate the extra cabling and tradeoffs associated with current point-to-point interface solutions.isl7202 Intersil

The ISL72026SEH, ISL72027SEH, and ISL72028SEH 3.3-V CAN transceivers deliver ultra-high performance in the most demanding environments by leveraging Intersil’s proprietary silicon on insulator process, which provides single event latch-up (SEL) and single event burn-out (SEB) robustness in heavy ion environments. With the emergence of all-electric propulsion satellites that maximize payload but take longer to reach final orbit, customers require higher total dose testing for mission assurance. Intersil’s CAN transceivers are low dose rate tested up to 75 krad on a wafer-by-wafer basis, and apply single event transient (SET) mitigation techniques to reduce system level bit error rates, providing predictable performance. They are also “cold spare” redundant capable, allowing the connection of additional unpowered transceivers to the CAN bus. This mission-critical capability maximizes system life.

  • The ISL7202xSEH family offers a number of unique features:
  • The ISL72026SEH includes a loopback test capability that allows node diagnostics and reporting while the system is transmitting data

It offers split termination output using the VREF pin to provide a VCC/2 output reference. This improves network electromagnetic compatibility and stabilizes the bus voltage, preventing it from drifting to a high common-mode voltage during inactive periods. The ISL72028SEH includes a low power shutdown mode that switches off the driver and receiver to draw 50 µA for power conservation.

Key features and specs:

  • Electrically screened to SMD 5962-15228, and compatible with ISO11898-2
  • Delivers 4-kV human body model (HBM) ESD protection on all pins
  • 3- to 3.6-V supply range, –7 to 12 V common-mode input voltage range, 5-V tolerant logic inputs, and bus pin fault protection to ±20-V terrestrial and ±18 V in orbit
  • Cold spare powered down devices do not affect active devices operating in parallel
  • Three selectable driver rise and fall times
  • Glitch free bus I/O during power-up and power-down
  • Full fail-safe receiver: open, short, terminated/undriven
  • Hi Z input allows for 120 nodes on the bus and data rates up to 1 Mbps
  • Low quiescent supply current of 7 mA
  • Thermal shutdown
  • Low dose rate (0.01 rad(Si)/s) radiation tolerance of 75 krad(Si)
  • SEL/B immune up to LET 60 MeV.cm2/mg

The ISL72026SEH, ISL72027SEH and ISL72028SEH 3.3V CAN transceivers are available in eight-lead ceramic flatpack packages.

Source: Intersil Corp.

Small, Self-Contained GNSS Receiver

TM Series GNSS modules are self-contained, high-performance global navigation satellite system (GNSS) receivers designed for navigation, asset tracking, and positioning applications. Based on the MediaTek chipset, the receivers can simultaneously acquire and track several satellite constellations, including the US GPS, Europe’s GALILEO, Russia’s GLONASS, and Japan’s QZSS.

LinxThe 10-mm × 10-mm receivers are capable of better than 2.5-m position accuracy. Hybrid ephemeris prediction can be used to achieve less than 15-s cold start times. The receiver can operate down to 3 V and has a 20-mA low tracking current. To save power, the TM Series GNSS modules have built-in receiver duty cycling that can be configured to periodically turn off. This feature, combined with the module’s low power consumption, helps maximize battery life in battery-powered systems.

The receiver modules are easy to integrate, since they don’t require software setup or configuration to power up and output position data. The TM Series GNSS receivers use a standard UART serial interface to send and receive NMEA messages in ASCII format. A serial command set can be used to configure optional features. Using a USB or RS-232 converter chip, the modules’ UART can be directly connected to a microcontroller or a PC’s UART.

The GPS Master Development System connects a TM Series Evaluation Module to a prototyping board with a color display that shows coordinates, a speedometer, and a compass for mobile evaluation. A USB interface enables simple viewing of satellite data and Internet mapping and custom software application development.
Contact Linx Technologies for pricing.

Linx Technologies