AD7150 Datasheet, PDF (1/28 Pages) Analog Devices – Ultra-Low Power, 2-Channel, Capacitance Converter for Proximity Sensing

Ultra-Low Power, 2-Channel, Capacitance
Converter for Proximity Sensing
AD7150
FEATURES
Ultra-low power
2.7 V to 3.6 V, 100 μA
Response time: 10 ms
Adaptive environmental compensation
2 independent capacitance input channels
Sensor capacitance (CSENS) 0 pF up to 13 pF
Sensitivity to 1 fF
EMC tested
2 modes of operation
Standalone with fixed settings
Interfaced to a microcontroller for user-defined settings
2 proximity detection output flags
2-wire serial interface (I²C compatible)
Operating temperature
−40°C to +85°C
10-lead MSOP package
APPLICATIONS
Proximity sensing
Contactless switching
Position detection
Level detection
GENERAL DESCRIPTION
The AD7150 delivers a complete signal processing solution for
capacitive proximity sensors, featuring an ultra-low power
converter with fast response time. The AD7151 is a single-
channel, lower power alternative to the AD7150.
The AD7150 uses 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 AD7150 operates in standalone mode using the
fixed power-up settings and indicates detection on two digital
outputs. Alternatively, the AD7150 can be interfaced to a
microcontroller 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 AD7150 operates with a 2.7 V to 3.6 V power supply. It is
specified over the temperature range of −40°C to +85°C.
FUNCTIONAL BLOCK DIAGRAM
VDD
C_SENS1
C_SENS2
CIN1
EXC1
CIN2
EXC2
MUX
Σ-Δ CDC
AD7150
EXCITATION
DIGITAL
FILTER
THRESHOLD
THRESHOLD
SERIAL
INTERFACE
GND
Figure 1.
SCL
SDA
OUT1
OUT2
Rev. 0
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