AD7156 Series

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

Catalog

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

Part	Sensor Type	Embedded	Interface	Supplied Contents	Voltage - Supply [Max]	Voltage - Supply [Min]	Utilized IC / Part	Supplier Device Package	Operating Temperature [Max]	Operating Temperature [Min]	Data Interface	Voltage Supply Source	Package / Case	Type	Resolution (Bits)	Sampling Rate (Per Second)	Mounting Type	Number of Channels [custom]
Analog Devices EVAL-AD7156EBZ	Touch Capacitive		I2C	Board(s)	3.6 V	1.8 V	AD7156
Analog Devices AD7156BCPZ-REEL					3.6 V	1.8 V		10-LFCSP-WD (3x3)	85 °C	-40 °C	Serial	Single Supply	10-VFDFN Exposed Pad CSP	Capacitance-to-Digital Converter	12 b	100k	Surface Mount	2

Catalog

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

Key Features

• Ultralow powerPower supply voltage: 1.8 V to 3.6 VOperation power supply current: 70 μA typicalPower-down current: 2 μA typical

• Fast response timeConversion time: 10 ms per channelWake-up time from serial interface: 300 μs

• Adaptive environmental compensation

• 2 capacitance input channelsSensor capacitance (CSENS): 0 pF up to 13 pFSensitivity up to 3 fF

• 2 modes of operationStandalone with fixed settingsInterfaced to a microcontroller for user-defined settings

• 2 detection output flags

• 2-wire serial interface (I2C-compatible)

• Operating temperature: −40°C to +85°C

• 10-lead LFCSP package (3 mm × 3 mm × 0.8 mm)

Description

The AD7156 delivers a complete signal processing solution for capacitive sensors, featuring an ultralow power converter with fast response time.The AD7156 uses an Analog Devices, Inc., capacitance-to-digital converter (CDC) technology, which combines features important for interfacing to real sensors, such as high input sensitivity and high tolerance of both input parasitic ground capacitance and leakage current.The integrated adaptive threshold algorithm compensates for any variations in the sensor capacitance due to environmental factors like humidity and temperature or due to changes in the dielectric material over time.By default, the AD7156 operates in standalone mode using the fixed power-up settings and indicates detection on two digital outputs. Alternatively, the AD7156 can be interfaced to a micro-controller via the serial interface, the internal registers can be programmed with user-defined settings, and the data and status can be read from the part.The AD7156 operates with a 1.8 V to 3.6 V power supply. It is specified over the temperature range of −40°C to +85°C.ApplicationsButtons and switchesProximity sensingContactless switchingPosition detectionLevel detectionPortable products