New PCap04 smart capacitive sensing front end from ams

ams released the PCap04, a new configurable capacitive sensing front end which gives sensor manufacturers the ability to balance speed and resolution to match their design requirements.

When optimized for speed, the PCap04 can capture and digitize up to 50,000 sensor measurements per second. When sampling at a slower rate to optimize for precision, the PCap04 can achieve a measurement resolution of 8aF.

The configurability of the device also enables sensor manufacturers to trade measurement speed off against power consumption. In low-power mode, the PCap04 draws a current as low as 4.0µA. ams has developed a demonstration board with no external power supply, in which the PCap04 operates on the energy harvested from the RF field generated by an NFC reader such as a smartphone.

The PCap04’s output may be supplied as a PWM or PDM representation of the raw measured capacitance value. The device also features a DSP to process the sensor measurements and convert them into digital values transmitted via an I2C or SPI interface. It can handle input capacitance values over a broad range from as little as 1pF to as much as 100nF.