PCAP01 Capacitance-to-Digital Conversion Digital Signal Processor

PCAP01 Capacitance-to-Digital Conversion Digital Signal Processor

PCAP01 is a capacitance-to-digital converter with a digital signal processor. Its front end is based on ScioSense patented PICOCAP measuring principle.

This conversion principle offers high resolution at conversion times as short as 2 µs. Users benefit from outstanding flexibility with respect to power consumption, resolution or speed. 

The PCap01 can be used for grounded single and differential sensors as well as for floating single and differential sensors. With grounded capacitors the stray capacitance inside the chip will be compensated. With floating capacitors, further to the internal stray capacitance, the external stray capacitances as well get compensated. Additionally, the temperature can be measured by means of internal thermistors or external ones (platinum or others). The chip needs firmware to process the the raw measurement data and to convert them in appropriate results. 

ScioSense offer two versions of open-source firmware, one for pure compensates capacitance ratios and one for fully linearized and temperature compensated results.

PCAP01 Capacitance-to-Digital Conversion Digital Signal Processor

PCAP01 features and benefits


  • Dedicated ports for precision temperature measurement (with Pt1000 sensors)
  • Serial interfaces (SPI or I2C compatible)
  • Single power supply (2.1 to 3.6 V)
  • RISC processor core using Harvard architecture:
    48 x 48 bit RAM Data, 4k x 8 bit volatile program memory, 4k x 8 bit non-volatile (OTP) program memory


  • Digital measuring principle in CMOS technology
  • Up to 8 capacitances in grounded mode
  • Up to 4 capacitances in floating mode (potential- free and with zero bias voltage)
  • Compensation of internal (grounded) and external parasitic capacities (floating)
  • High resolution: up to 6 aF at 5 Hz and 10 pF base capacitance, or 17 bit resolution at 5 Hz with 100 pF base capacitance and 10 pF excitation
  • High measurement rate: up to 500 kHz
  • Extremely low current consumption possible:
    Down to 4 µA at 3 Hz with 13.4 bit resolution
  • High stability with temperature, low offset drift (down to 30 aF per Kelvin), low gain drift when all compensation options are activated.

Product properties

  • Supply voltage VDD-to-GND 0.3 to 4.0 V
  • Storage temperature Tstg 55 to 150 °C
  • ESD rating (HBM), each pin > 2 k
  • Junction temperature (Tj) max. 125 °C
  • OTP Data Retention Period 10 years at 95 °C temperature


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Evaluation kit

The PCAP01 evaluation system provides a complete system for generally evaluating the PCAP01 chip. It comprises of a main board, a plug-in module, a Windows based evaluation software, assembler software and the PICOPROG programming device. This kit can be used to evaluate the capacitance measurement, temperature measurement and the pulse generation capabilities of the PCAP01 chip.