The SD41x from SensorDynamics AG, Graz-Lebring, Austria, is a single-chip interface for AMR sensors commonly used in automotive applications. AMR sensors have <100 mV differential outputs and so must be amplified and filtered before being processed by the microcontroller. The SD41x integrates the necessary amplifiers, filters, ADCs, and microcontroller. The device has an integrated 8-bit microcontroller and two 14-bit sigma-delta ADCs; built-in fail-safe properties; built-in voltage regulators; several sleep-down modes; and is available with SPI, LIN, PW, UART, DAC data interfaces. The part is supplied with a development tool kit.