PicoCap Capacitance Measurement

PCAP02 Capacitance-to-Digital Converter

Capacitance-to-Digital Converter with Integrated Signal Processor

PCAP02 Capacitance-to-Digital ConverterPCAP02 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 provides great resolution with conversion times as short as 2 µs. Users benefit from exceptional versatility in terms of power usage, resolution, and speed.

The PCAP02 works with both grounded and floating single and differential sensors. Ground capacitors mitigate for stray capacitance inside the chip. Floating capacitors compensate for both internal and exterior stray capacitances. A pre-charge cycle increases the utility of MEMS sensors while simultaneously providing short-circuit safety. Temperature can be sensed using either internal or external thermistors (platinum or others). The chip requires firmware to process the raw measurement data and transform it into 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.

PicoCap: Capacitance Measurement

KEY FEATURES

  • Wide Input Range (fF to nF)
  • Low Noise (15 aF rms)
  • High Update Rate up to 500 kHz
  • Low Current Consumption down to 2 uA
  • Internal Signal Processor

KEY BENEFITS

  • Enables Platform Designs (one part – different configurations)
  • Enables Compact Designs Due to Internal Signal Processor
  • Allows for Low Power Designs (Example, wireless applications)
  • Enables Multi-Channel Designs (up to 8 sensors)
PCAP02 Block Diagram - Capacitance-to-Digital Converter

PCAP02 PRODUCT FACTS

Channels 8
Noise [aF@10pF]
15
Max. Rate [SPS]
500000
Operating Supply Range [V]
2.1 to 3.6
Interface SPI, I2C, PDM, PWM
CPU 48-bit
Memory 4k OTP
GPIO 6
Ambient Temperature Range [°C] -40°C to +125°C
Package QFN32

Documentation & Downloads

Evaluation Kit

For a quick and easy start-up with the PICOCAP product line, we offer a general evaluation kit. The system is connected to the PC’s USB interface through the PICOPROG programming device. A comfortable evaluation software allows to program and configure the PCAP02. The measurement data can be shown numerically and graphically. Finally, the data can be exported to text files for further analyses.

Evaluation Software

Ordering Numbers

Type
Part Number
Package
RoHS compl.
Shipping Package
PCap02:
PCap02A Dice Yes
PCap02AE QFN32 Yes
PCap02-EVA-KIT System Yes Box
PCap01:
PCap01A MNR 1613 Dice Yes
PCap01AD MNR 1793 QFN32 Yes
PCap01AK MNR 1795 QFN24 Yes
PCap01-EVA-KIT MNR 1912-01 System Yes Box
PCap01-HUM-EVA MNR 1796 System Yes Box
PCap01-HUM-DEMO MNR 1792 System Yes Box