PICOCAP: CAPACITANCE MEASUREMENT
Capacitance-to-Digital Converter with Integrated Signal Processor
The PCap01 is a capacitance-to-digital converter that offers an
unprecedent degree of flexibility. Thanks to the patented PICOCAP®
concept, the device
covers a capacitance input range from a few fF up to several hundreds of nF and can be easily configured to the various needs in all areas of capacitance measurement. The PCap01 suits to applications with lowest current consumption of only a few µA just as well as solutions that require highest precision of 20-Bit and more, or update rates of up to 500,000 measurements per second.
The sensor data can be linearized on-chip and is provided via SPI or IIC digital serial interfaces. Additionally, the device offers IO's for PWM/PDM signal outputs. Further IO's can be used for interrupts, alarm level indication or for general purpose.
The sensor data can be linearized on-chip and is provided via SPI or IIC digital serial interfaces. Additionally, the device offers IO's for PWM/PDM signal outputs. Further IO's can be used for interrupts, alarm level indication or for general purpose.
PCap01 Series
| Product | Part number | Package | Type |
|---|---|---|---|
| PCap01A | 1613 | Dice | Capacitance-to-Digital Converter for up to 8 capacitors, 5 GPIOs |
| PCap01AD | 1793 | QFN32 | Capacitance-to-Digital Converter for up to 8 capacitors, 5 GPIOs |
| PCap01AK | 1795 | QFN24 | Capacitance-to-Digital Converter for up to 6 capacitors, 5 GPIOs |
| Description | Version | Size | Download |
|---|---|---|---|
| Development Support PCap04: Evaluation System for PCap04 | V1.0 | 4MB | PCAP04EVAL- DS.PDF |
| Datasheet PCap04: General Data | V1.0 | 3.2 KB | PCAP04.PDF |
| Datasheet PCap02, Vol. 1: General Data and Front-End | V1.6 | 2.6MB | DB_PCap02A_Vol1_en.pdf |
| Datasheet PCap02, Vol. 2: Digital Signal Processor | V0.2 | 1.6MB | DB_PCap02A_Vol2_en.pdf |
| Datasheet PCap02 Eval System: Evaluation System for PCap02 | V0.0 | 990kB | DB_PCap02-EVA-Kit_en.pdf |
| Datasheet PCap02 Eval System: Evaluation Software for PICOCAP Devices | V0.0 | 2MB | DB_PCap02plus_en.pdf |
| Datasheet PICOCAP DEVICES: Assembler Software PICOCAP Devices | V0.0 | 750kB | DB_PCap-Assembler_en.pdf |
| Datasheet PCap02, Linearize: Description of Linearization Firmware | V0.2 | 1.2MB | DB_PCap02_Linearize_en.pdf |
| Datasheet PCap01: Single-chip solution with standard firmware | V0.6 | 5MB | DB_PCap01Ax_0301_en.pdf |
| Datasheet PCap01: Single-chip solution for humidity measurement | V0.3 | 4MB | DB_PCap01AK-0101xx_en.pdf |
| Datasheet PCap01: Description of PCap01 DSP and Assembler | V0.2 | 3MB | DB_PCap01_DSP_e.pdf |
| Datasheet PCap01: General evaluation kit for PCap01 | V0.3 | 2.6MB | DB_PCap01-EVA-KIT_en.pdf |
| Datasheet PCap01: Description of humidity measurement demonstrator | V0.1 | 3MB | DB_PCap01_HUM_DEMO_en.pdf |
| Datasheet PCap01-Touch: Very-Low-Power IC for Capacitive Touch Sensor Solutions | V0.1 | 1.3MB | DB_PCap01_Touch_en.pdf |
| Description | Version | Size | Download |
|---|---|---|---|
| Screencasts PCap01: 2:44 min. webcast introduction into PCap01 Evaluation Kit | - | 7MB | PCap01_Evaluation-Software_en.zip |
| Screencasts PCap02plus: 9:37 min. webcast introducing a Sensor Scaling + PDM / PWM output with PCap02 | - | 26MB | PCap02plus-Scaling-PDM-PWM_en.zip |
| Description | Version | Size | Download |
|---|---|---|---|
| Software PCap04: Evaluation software for PICOCAP Devices Full installer package incl. drivers | 1.2.7 | 297MB | PCap04-EVA-SW_W7.zip |
| Software PCap04 (32-bit): Using our DLL combing with your own software. ZIP package incl. e.g. header file, example c-code | 1.0 | 423kB | PCap04-DLL-Library.zip |
| Software PCap04 (64-bit): Using our DLL combing with your own software. ZIP package incl. e.g. header file, example c-code | 1.0 | 378kB | linearize_r01.zip |
| Software PCap02: Evaluation software for PICOCAP Devices Full installer package incl. drivers | 1.3.1 | 168MB | PCap02plus.zip |
| Software PCap01: Evaluation software for PCap01-EVA-KIT and PCap01-HUM-EVA Full installer package incl. drivers | 0.80 | 150MB | PCap01-EVA-SW_W7_XP.zip |
| Software PCap01: Assembler software for PCap01, installer package | V20.4 | 160MB | PCap01_Assembler.zip |
| Software PCap01: Standard firmware for PCap01A | 03.01.02 | 25k | PCap01_standard.hex |
| Software PCap01: Firmware for humidity+temperature measurement | 01.01.04 | 25k | PCap01_humidity.hex |
| Software PICOPROG V3 (V2.0): Driver Installer Stand-Alone | R11 | 3.1MB | PicoProg_v2_Driver_Installer_Stand-Alone.zip |
The PICOCAP measuring principle shows a new approach to capacitance measurement. For this purpose the sense capacitor and a reference capacitor are connected to a resistor, forming a low-pass filter. Sense and reference capacitor should be in the same range to minimize gain drift. Practically there is no limit for the capacitor value. Sensors from nearly 0 fF up to tens of nF can be measured. The PICOCAP devices also support differential sensors with inside linearization.
The capacitors are charged to the supply voltage and then discharged through the resistor. The discharge time down to an arbitrary trigger level is measured with ultra-high precision using a TDC (Time-to-Digital Converter).
This measuring process is repeated in time-multiplex with both Capacitors, using the same resistor and the same comparator. Calculating the ratio of the results will turn out the absolute values and temperature dependencies of the resistor and the comparator.
The Compensated Mode offers the solution for highest resolution applications with low offset and extremely low gain drift. The capacitors are connected floating, not referenced to ground. They are switched alternately to the resistor by an integrated analog switch. Additional patented circuits and algorithms compensate for parasitic capacities. Parasitic capacities would have a negative effect on the gain drift over temperature. The compensation results in a very low gain drift over temperature down to 0.5 ppm / K. It is much better than the intrinsic gain drift of most sensors.
| 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 |