• Visit our detailed system design support and FAQ page.
• View our Touch Control Demo.

The AD7147 is designed for use with capacitance sensors implementing functions such as buttons, scroll bars, and wheels. The sensors need only one PCB layer, enabling ultra thin 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 V_DRIVE pin to set the voltage level for the serial interface independent of V_CC.

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 consumption 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

Data Sheet, Rev. 0, 9/07

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	$1.35	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	$1.24	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
AD7150	12	100SPS	2	Single(+2.7 to +3.6)	0.43mW	10	±4	SOP	$1.35	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	$1.35	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	$4.60	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	$4.95	24-bit, Cap-to-Dig Conv. w/ 2 SE/Diff Capacitive Input Ch for interface to Dual Electrode Cap Sensor	I²C/Ser 2-Wire
AD7747	24	45.5SPS	1	Single(+2.7 to +5.25)	4.25mW	17	±8	SOP	$4.60	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.

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For detailed drawings and chemical composition please consult our  Package Site

Pin Count is the number of pins, balls, or pads on the device. Pin-out diagrams & pin function descriptions may be found in the datasheet.

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• Automotive: -40 to +125 degrees Celsius

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