Six-Channel RS-422 Line Driver/Receiver

ic-HausThe iC-HF provides six RS-422 line drivers for 3-to-5.5-V encoder applications. The device contains reverse polarity protection for a safe sensor-side supply of up to 60 mA.

The iC-HF is pin configurable. A safe external signal sequence at two complementary line driver outputs activates the Encoder Link state. In the Encoder Link state, nine pins are connected from the sensor side to the field side. With this low-impedance bypassing, internal analog sensor signals and digital communication signals (e.g., BiSS, SPI, I²C, etc.) can be accessed at the line driver output pins.

With the integrated Encoder Link function, the line drivers can be deactivated and A/D signals can be directly accessed through the line driver output pins. Conventional sensors can be calibrated or programmed through the usual RS-422 outputs via the Encoder Link function. Extra contacts, pins, control lines, or signals are not needed. For differential RS-422 line driver operation, six differential complementary drivers are implemented.

Each push-pull driver stage can drive up to 65 mA maximum at 5 V and operate at up to a 10-MHz output frequency with RS-422 termination. The driver stages are current limited, short-circuit proof, and over-temperature protected. The current limitation also reduces electromagnetic compatibility (EMC).

The device provides under-voltage detection and on-chip temperature monitoring to switch the driver stages to high impedance on demand. A sensor error signal is combined with the iC-HF error states. When a fault occurs, the open-drain error output NERR is activated. All inputs are CMOS- and TTL-compatible and ESD protected.

The iC-HF’s operating temperatures range from –40°C to 125°C. The device is available in a 5-mm × 5-mm 32-pin QFN package. The design-in process is supported by ready-to-operate demonstration boards including the Encoder Link signal sequence generator.

The iC-HF costs $3.65 in 1,000-unit quantities.

iC-Haus GmbH
www.ichaus.com

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