AD7147:  CapTouch™ Programmable Controller for Single-Electrode Capacitance Sensors

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 ...More

Demo

AD7147:  CapTouch™ Programmable Controller for Single-Electrode Capacitance Sensors

Product Description

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.

Applications

  • Cell phones
  • Personal music and multimedia players
  • Smart handheld devices
  • Television, A/V, and remote controls
  • Gaming consoles
  • Digital still cameras

Features

  • Programmable capacitance-to-digital converter (CDC)
    See data sheet
  • On-chip automatic calibration logic
    See data sheet
  • Register map is compatible with the AD7142
  • On-chip RAM to store calibration data
  • SPI-compatible (serial-peripheral-interface-compatible) serial interface (AD7147)
  • I2C-compatible serial interface (AD7147-1)
  • Separate VDRIVE level for serial interface
  • See data sheet for additional features

Diagrams

AD7147 Diagram
Block Diagram for AD7147

Specifications

Resolution (Bits) 16bit
T-Put Rate 111SPS
# Chan 13
Supply V Single(+3),Single(+3.3)
Pwr Diss (max) 3.6mW
Sleep Pwr Diss 24.8µW
Ain Range ± 8 pF (Delta C)
Ref Int/Ext Int
Product Description CAPTouch (TM) Programmable Controller w/ SPI or I2C Interface for Single-Electrode Cap Sensors

Explore Other Products

AD7156 - Ultralow Power, 1.8 V, 3 mm × 3 mm, 2-Channel Capacitance Converter

Subscribe to New Products Feed
Part# Resolution (Bits) T-Put Rate # Chan Supply V Pwr Diss (max) Input Base C (pF Max) Cin Range (pF) Pkg Type Price* (1000-4999) Product Description Interface
AD7142 16 27.8SPS 14 Single(+2.6 to +3.6), Single(+2.7), Single(+3), Single(+3.3) 3.6mW 20 ±2 CSP $1.37 CAPTouch (TM) Programmable Controller for 2-Electrode Capacitance Sensor with SPI or I2C Interface I²C/Ser 2-Wire, Ser, SPI
AD7143 16 43.5SPS 8 Single(+2.6 to +3.6) 3.6mW 20 ±2 CSP $1.25 CAPTouch (TM) Programmable Controller for 2-Electrode Capacitance Sensor with I2C Interface I²C/Ser 2-Wire, Ser
AD7147 16 111SPS 13 Single(+3), Single(+3.3) 3.6mW 20 ±8 CSP $1.30 CAPTouch (TM) Programmable Controller w/ SPI or I2C Interface for Single-Electrode Cap Sensors I²C/Ser 2-Wire, Ser, SPI
AD7148 16 4SPS 8 Multi(+3.3Anlg, +3.3Dig) 3.3mW 20 ±8 CSP $1.21 Programmable Touch Controller for Single Electrode Capacitance Sensors I²C/Ser 2-Wire, Ser
AD7150 12 100SPS 2 Single(+2.7 to +3.6) 0.43mW 10 ±4 SOP $1.37 Ultra-Lo Pwr, 2-Ch Capacitance Converter for Proximity Sensing Applications I²C/Ser 2-Wire, Ser
AD7151 12 100SPS 1 Single(+2.7 to +3.6) 0.3mW 10 ±4 SOP $1.37 Ultra-Low Power, 1-Ch, Capacitance Converter for Proximity Sensing Applications I²C/Ser 2-Wire, Ser
AD7745 24 90SPS 1 Single(+2.7 to +5.25) 4.25mW 17 ±4 SOP $4.66 24-Bit, Cap-to-Dig Conv. w/ 1 SE/Diff Capacitive Input Ch for Interface to Dual Electrode Cap Sensor I²C/Ser 2-Wire, Ser
AD7746 24 90SPS 2 Single(+2.7 to +5.25) 4.25mW 17 ±4 SOP $5.01 24-bit, Cap-to-Dig Conv. w/ 2 SE/Diff Capacitive Input Ch for interface to Dual Electrode Cap Sensor I²C/Ser 2-Wire, Ser
AD7747 24 45.5SPS 1 Single(+2.7 to +5.25) 4.25mW 17 ±8 SOP $4.66 24-bit, Cap-to-Dig Conv w/1 SE/Diff Capacitive Input Ch for interface to Single Electrode Cap Sensor I²C/Ser 2-Wire, Ser

* The pricing listed here is provided only for budgetary purposes as recommended list price in U.S. Dollars in the United States ex factor per unit for the stated volume. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
** Pricing is currently unavailable. Click on the product number to see the Product Page for additional information.

Pricing, Packaging & Availability