Ultralow Power, 2-Channel, Capacitance Converter for Proximity Sensing Data Sheet AD7150 FEATURES GENERAL DESCRIPTION Ultralow power The AD7150 delivers a complete signal processing solution for 2.7 V to 3.6 V, 100 A capacitive proximity sensors, featuring an ultralow power Response time: 10 ms converter with fast response time. The AD7151 is a single- Adaptive environmental compensation channel, lower power alternative to the AD7150. 2 independent capacitance input channels The AD7150 uses Analog Devices, Inc., capacitance-to-digital Sensor capacitance (C ) 0 pF up to 13 pF SENS converter (CDC) technology, which combines features Sensitivity to 1 fF important for interfacing to real sensors, such as high input EMC tested sensitivity and high tolerance of both input parasitic ground 2 modes of operation capacitance and leakage current. Standalone with fixed settings The integrated adaptive threshold algorithm compensates for Interfaced to a microcontroller for user-defined settings any variations in the sensor capacitance due to environmental 2 proximity detection output flags 2 factors like humidity and temperature or due to changes in the 2-wire serial interface (I C compatible) dielectric material over time. Operating temperature 40C to +85C By default, the AD7150 operates in standalone mode using the 10-lead MSOP package fixed power-up settings and indicates detection on two digital outputs. Alternatively, the AD7150 can be interfaced to a APPLICATIONS microcontroller via the serial interface, the internal registers can Proximity sensing be programmed with user-defined settings, and the data and Contactless switching status can be read from the part. Position detection The AD7150 operates with a 2.7 V to 3.6 V power supply. It is Level detection specified over the temperature range of 40C to +85C. FUNCTIONAL BLOCK DIAGRAM VDD CIN1 SCL C DIGITAL SERIAL SENS1 - CDC FILTER INTERFACE SDA EXC1 MUX AD7150 THRESHOLD OUT1 CIN2 C SENS2 EXCITATION EXC2 THRESHOLD OUT2 GND Figure 1. Rev. A Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20072019 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 06517-001AD7150 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Fixed Threshold Registers ......................................................... 16 Applications ....................................................................................... 1 Sensitivity Registers ................................................................... 16 General Description ......................................................................... 1 Timeout Registers ....................................................................... 17 Functional Block Diagram .............................................................. 1 Setup Registers ............................................................................ 18 Revision History ............................................................................... 2 Configuration Register .............................................................. 19 Specif icat ions ..................................................................................... 3 Power-Down Timer Register .................................................... 20 Timing Specifications .................................................................. 4 CAPDAC Registers .................................................................... 20 Absolute Maximum Ratings ............................................................ 5 Serial Number Register .............................................................. 20 ESD Caution .................................................................................. 5 Chip ID Register ......................................................................... 20 Pin Configuration and Function Descriptions ............................. 6 Serial Interface ................................................................................ 21 Typical Performance Characteristics ............................................. 7 Read Operation........................................................................... 21 Architecture and Main Features ................................................... 10 Write Operation.......................................................................... 21 Capacitance-to-Digital Converter ............................................ 10 AD7150 Reset ............................................................................. 22 CAPDAC ..................................................................................... 10 General Call ................................................................................ 22 Comparator and Threshold Modes .......................................... 11 Hardware Design Considerations ................................................ 23 Adaptive Threshold .................................................................... 11 Overview ..................................................................................... 23 Data Average ............................................................................... 11 Parasitic Capacitance to Ground .............................................. 23 Sensitivity..................................................................................... 12 Parasitic Resistance to Ground ................................................. 23 Hysteresis ..................................................................................... 12 Parasitic Parallel Resistance ...................................................... 23 Timeout ........................................................................................ 12 Parasitic Serial Resistance ......................................................... 24 AutoCAPDAC Adjustment ....................................................... 13 Input Overvoltage Protection ................................................... 24 Power-Down Timer ................................................................... 13 Input EMC Protection ............................................................... 24 Power Supply Monitor ............................................................... 13 Power Supply Decoupling and Filtering .................................. 24 Register Descriptions ..................................................................... 14 Application Examples ................................................................ 25 Status Register ............................................................................. 15 Outline Dimensions ....................................................................... 26 Data Registers ............................................................................. 16 Ordering Guide .......................................................................... 26 Average Registers ........................................................................ 16 REVISION HISTORY 6/2019Rev. 0 to Rev. A. Changes to Address Pointer 0x13, 0x14, 0x15, 0x16 32 Bits, Read-Only, 0xXXXXa Section ...................................................... 20 Changes to Ordering Guide .......................................................... 26 11/2007Revision 0: Initial Version Rev. A Page 2 of 28