Renesas Electronics ZSSC3123 cLite™ Sensor Signal Conditioner

Renesas Electronics ZSSC3123 cLite™ Capacitive Sensor Signal Conditioner (SSC) is a CMOS integrated circuit for accurate capacitance-to-digital conversion and sensor-specific correction of capacitive sensor signals. Digital compensation of sensor offset, sensitivity, and temperature drift is accomplished via an internal digital signal processor running a correction algorithm with calibration coefficients stored in a nonvolatile EEPROM.

Renesas Electronics ZSSC3123 cLite™ Capacitive SSC is configurable for capacitive sensors with capacitances up to 260pF and sensitivity of 125aF/LSB to 1pF/LSB depending on resolution, speed, and range settings. It is compatible with single capacitive sensors (both terminals must be accessible) and differential capacitive sensors. Measured and corrected sensor values can be output as I²C, SPI, PDM, or alarms.

The I²C interface can be used for a simple PC-controlled calibration procedure to program a set of calibration coefficients into an on-chip EEPROM. The calibrated ZSSC3123 and a specific sensor are mated digitally, which is fast, precise, and without the cost overhead of trimming by external devices or laser.

Features

260pF max target input capacitance
0.7ms sampling rates at 8-bit / 1.6ms at 10-bit / 5ms at 12-bit / 18.5ms at 14-bit
Piece-wise 1st and 2nd order sensor compensation or up to 3rd order single-region sensor compensation
Digital compensation of 1st and 2nd order temperature gain and offset drift
Internal temperature compensation reference (no external components)
Programmable capacitance span and offset
Layout customized for die-die bonding with sensor for high-density chip-on-board assembly
Accuracy as high as ±0.25% full-scale output at -40°C to +125°C, 3V, 5V, Vsupply ±10%
Minimized calibration costs with no laser trimming and one-pass calibration using a digital interface

Wide capacitance range to support a broad portfolio of different sensor elements
Excellent for low-power battery applications
Two interface options
- I²C or SPI interface (easy connection to a microcontroller)
- PDM outputs (Filtered Analog Ratiometric) for both capacitance and temperature
Up to two alarms that can act as full push-pull or open-drain switches
2.3V to 5.5V supply voltage
750μA to 60μA typical current consumption depending on configuration
≤1μA at 85°C typical sleep mode current rating
-40°C to +125°C operating temperature range
Die or TSSOP-14 package