The ZMD21013 belongs to ZMDI’s MUlti-channel/MUlti-use Sensor Interface (MUSic™) IC family, which has a focus on sensor-controlled, batterypowered,
microcontroller-based mobile electronic products. The ZMD21013 is an integrated, multichannel, high-precision, resistive sensor interface IC, especially suited for low-power applications. It amplifies and digitizes the voltage signals of up to three connected sensors. These sensors are only switched on for sampling, so the overall sensorinterface system consumes less power.
The versatile ZMD21013 can be adapted to almost any resistive sensor type and provides an optional temperature measurement. It is optimized for bridgetype sensors, which typically operate in a standard voltage-driven mode. It provides three selectable input channels. The analog-to-digital (A/D) conversion resolution and time, input range, sensitivity, and measurement mode are programmable. The measurement values are provided via a flexible digital serial interface.
In each measurement mode, the optional auto-zeromode allows compensation of the circuitry’s offsets and offset drifts. The ZMD21013 contains an RC clock generator and integrated 16 x 8-bit EEPROM for permanent storage of configuration data.

• Temperature measurement mode fully supported
• Completely ratiometric systems
• On-chip EEPROM for configuration and calibration data
• Internal clock generator (RC oscillator)
• Input multiplexer for independent bridges
• Voltage-driven (switched or static) bridge mode
• Internal auto-zero mode
• Low-noise switched-capacitor (SC) amplifier with offset compensation and adaptive operational amplifier biasing
• Full-duplex, high-throughput, flexible digital communication interface (SPI)

• Low-power (typically 25 μW at VDD = 3V, 16 bit resolution, 1 value/s), high-sensitivity (down to 0.9 μV/V), multi-channel sensor interface IC
• Universally compatible with any resistive bridge sensor; e.g., piezo-resistive or ceramic thick-film
• Programmable amplification and A/D conversion (resolution and conversion time) of sensor input signals