PCAP01AK

ADCs/DACs - Special Purpose Overview

The PCAP01AK is a single-chip capacitance-to-digital converter featuring an integrated DSP. It utilizes the patented PICOCAP measurement principle to achieve high resolution with conversion times as short as 2 µs. The device supports up to 8 grounded or 4 floating capacitive sensors, compensating for internal and external stray capacitances. It includes a RISC processor core with Harvard architecture, offering 4k x 8-bit volatile program memory and 4k x 8-bit OTP memory. Operating on a single supply of 2.1 V to 3.6 V, it provides SPI or I2C interfaces and can consume as low as 4 µA at 3 Hz.

ADCs/DACs - Special Purpose Feature Summary

• High-resolution capacitance measurement: up to 6 aF RMS noise at 5 Hz with 10 pF base capacitance.
• Flexible sensor configuration: Supports up to 8 grounded or 4 floating single/differential sensors.
• Integrated DSP with Harvard architecture: Includes 48 x 48 bit RAM data and non-volatile OTP programming.
• Low power consumption: Down to 4 µA at 3 Hz output rate with 13.4-bit resolution.

ADCs/DACs - Special Purpose Applications

• Humidity sensors
• Level sensors
• Position and pressure sensors
• MEMS sensors

ADCs/DACs - Special Purpose Procurement Notes

Verify the QFN24 package dimensions (4.00 mm x 2.70 mm) against PCB footprint requirements. Ensure the design accommodates the mandatory BUFFCAP bypassing pins. Confirm that the application voltage remains within the 2.1 V to 3.6 V operating range to maintain specified precision and stability.

ADCs/DACs - Special Purpose Selection Notes

Select the PCAP01AK over the PCAP01AD when a reduced pin count is required, as the AK variant lacks external oscillator pins and has fewer capacitor ports. Evaluate the trade-off between measurement speed and current consumption using the provided tables; lower data rates significantly reduce power usage. Consider the need for linear regulators due to poor PSRR characteristics.

ADCs/DACs - Special Purpose Part Context

The PCAP01AK is part of the PCapØ1Ax family from acam-messelectronic gmbh, now part of the ams Group. This series represents a digital solution for capacitance measurement, replacing complex analog front-ends. The 'AK' suffix specifically denotes the QFN24 package variant, which offers a compact form factor compared to the QFN32 AD version.

ADCs/DACs - Special Purpose Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult the manufacturer's sales channels for potential obsolescence notices or alternative component recommendations if the PCAP01AK becomes unavailable.

ADCs/DACs - Special Purpose FAQ

What is the difference between the PCAP01AK and PCAP01AD packages?

The PCAP01AK uses a QFN24 package with a reduced number of capacitor ports and no external oscillator pins, whereas the PCAP01AD uses a QFN32 package with all pins available.

How does the chip handle stray capacitance?

In grounded mode, the chip compensates for internal stray capacitance. In floating mode, it compensates for both internal and external stray capacitances.

Is an external clock required for operation?

No, the PCAP01AK does not require an external clock. It features an internal RC-oscillator that can be set between 10 kHz and 200 kHz.