The AD7147 CapTouch™ controller is designed for use with capacitance sensors implementing functions such as buttons, scroll bars, and wheels. The sensors need only one PCB layer, enabling ultrathin applications.
The AD7147 is an integrated CDC with on-chip environmental calibration. The CDC has 13 inputs channeled through a switch matrix to a 16-bit, 250 kHz sigma-delta (Σ-Δ) converter. The CDC is capable of sensing changes in the capacitance of the external sensors and uses this information to register a sensor activation. By programming the registers, the user has full control over the CDC setup.
High resolution sensors require minor software to run on the host processor.
The AD7147 is designed for single electrode capacitance sensors (grounded sensors). There is an active shield output to minimize noise pickup in the sensor.
The AD7147 has on-chip calibration logic to compensate for changes in the ambient environment. The calibration sequence is performed automatically and at continuous intervals as long as the sensors are not touched. This ensures that there are no false or nonregistering touches on the external sensors due to a changing environment.
The AD7147 has an SPI-compatible serial interface, and the AD7147-1 has an I2C®-compatible serial interface. Both parts have an interrupt output, as well as a GPIO. There is a VDRIVE pin to set the voltage level for the serial interface independent of VCC.
The AD7147 is available in a 24-lead, 4 mm × 4 mm LFCSP and operates from a 2.6 V to 3.6 V supply. The operating current con-sumption in low power mode is typically 26 μA for 13 sensors.
Features and Benefits
| Analog to Digital ConvertersSecurity and Surveillance
Building Technology
Software & Systems Requirements |
| Document | note |
| AD7147: CapTouch Programmable Controller for Single-Electrode Capacitance Sensors Data Sheet (Rev. E) | PDF 1397 kB |
| Document | note |
| Leading Inside Advertorials: Providing an Edge in Capacitive Sensor Applications | PDF 85 kB |
| Document | note |
| Part Number | Package | Packing Qty | Temp Range | Price 100-499 | Price 1000+ | RoHS |
|---|---|---|---|---|---|---|
| AD7147ACPZ-1500RL7 Production | 24 ld LFCSP 4x4mm (2.5EP) | OTH 500 | -40 to 85C | 0 | 1.28 | Y |
| AD7147ACPZ-1REEL Production | 24 ld LFCSP 4x4mm (2.5EP) | REEL 5000 | -40 to 85C | 0 | 1.28 | Y |
| AD7147ACPZ-500RL7 Production | 24 ld LFCSP 4x4mm (2.5EP) | OTH 500 | -40 to 85C | 0 | 1.28 | Y |
| AD7147ACPZ-REEL Production | 24 ld LFCSP 4x4mm (2.5EP) | REEL 5000 | -40 to 85C | 0 | 1.28 | Y |
| AD7147PACPZ-1500R7 Production | 24 ld LFCSP 4x4mm (2.5EP) | OTH 500 | -40 to 85C | 0 | 1.28 | Y |
| AD7147WPACPZ-1500R Production | 24 ld LFCSP 4x4mm (2.5EP) | OTH 500 | -40 to 85C | 0 | 1.38 | Y |
| AD7147WPACPZ-1RL Production | 24 ld LFCSP 4x4mm (2.5EP) | REEL 5000 | -40 to 85C | 0 | 1.38 | Y |
| AD7147WPACPZ-500R7 Production | 24 ld LFCSP 4x4mm (2.5EP) | OTH 500 | -40 to 85C | 0 | 1.38 | Y |
| AD7147WPACPZ-RL Production | 24 ld LFCSP 4x4mm (2.5EP) | REEL 5000 | -40 to 85C | 0 | 1.38 | Y |
| Part Number | Description | Price | RoHS |
|---|---|---|---|
| EVAL-AD7147-1EBZ | AD7147 Evaluation Board – I2C version | 177.1 | Y |
| EVAL-AD7147EBZ | Evaluation Board | 177.1 | Y |
