SX9500 Ultra Low Power, Four Channels Capacitive Proximity/Button Solution WIRELESS & SENSING GENERAL DESCRIPTION KEY PRODUCT FEATURES The SX9500 is a low-cost, very low power 4-channel 2.7 5.5V Input Supply Voltage capacitive controller that can operate either as a proximity or Capacitive Sensor Inputs button sensor. The SX9500 includes sophisticated on-chip Down to 0.08 fF Capacitance Resolution auto-calibration circuitry to regularly perform sensitivity Stable Proximity & Touch Sensing With Temperature adjustments, maintaining peak performance over a wide Capacitance Offset Compensation to 30pF variation of temperature, humidity and noise environments, providing simplified product development and enhanced Active Sensor Guarding performance. Automatic Calibration Ultra Low Power Consumption: The SX9500 operates directly from an input supply voltage of Active Mode: 170 uA 2.7 to 5.5V, and includes a separate I2C serial bus supply Doze Mode: 18 uA input to enable communication with 1.8 5.5V hosts. The Sleep Mode: 2.5 uA I2C serial communication bus reports proximity or touch detection and is used to facilitate parameter settings 400KHz I2C Serial Interface adjustment. Upon a proximity detection, the NIRQ output Four programmable I2C Sub-Addresses asserts, enabling the user to either determine the relative Input Levels Compatible with 1.8V Host Processors proximity distance, or simply obtain an indication of Open Drain NIRQ Interrupt pin detection. Three (3) Reset Sources: POR, NRST pin, Soft Reset A dedicated transmit enable (TXEN) pin is available to -40C to +85C Operation synchronize capacitive measurements for applications that Compact Size: 3 x 3mm Thin QFN package require synchronous detection, enabling very low supply current and high noise immunity by only measuring proximity Pb & Halogen Free, RoHS/WEEE compliant when requested. APPLICATIONS Notebooks Tablets Mobile Appliances ORDERING INFORMATION Part Number Package Marking 1 QFN-20 ZND8 SX9500IULTRT SX9500EVKA Eval. Kit 1 3000 Units/reel TYPICAL APPLICATION CIRCUIT Revision 4 February 4, 2014 2014 Semtech Corporation www.semtech.com 1 SX9500 Ultra Low Power, Four Channels Capacitive Proximity/Button Solution WIRELESS & SENSING Table of Contents GENERAL DESCRIPTION ........................................................................................................................ 1 KEY PRODUCT FEATURES..................................................................................................................... 1 APPLICATIONS ....................................................................................................................................... 1 ORDERING INFORMATION...................................................................................................................... 1 TYPICAL APPLICATION CIRCUIT ............................................................................................................ 1 1 GENERAL DESCRIPTION ............................................................................................................... 4 1.1 Pin Diagram 4 1.2 Marking Information 4 1.3 Pin Description 5 1.4 Acronyms 5 2 ELECTRICAL CHARACTERISTICS ................................................................................................. 6 2.1 Absolute Maximum Ratings 6 2.2 Operating Conditions 6 2.3 Thermal Characteristics 6 2.4 Electrical Specifications 7 3 PROXIMITY SENSING INTERFACE ................................................................................................. 9 3.1 Introduction 9 3.2 Scan Period 9 3.3 Analog Front-End (AFE) 10 3.3.1 Capacitive Sensing Basics 10 3.3.2 AFE Block Diagram 12 3.3.3 Capacitance-to-Voltage Conversion (C-to-V) 12 3.3.4 Shield Control 12 3.3.5 Offset Compensation 12 3.3.6 Analog-to-Digital Conversion (ADC) 13 3.4 Digital Processing 13 3.4.1 Overview 13 3.4.2 PROXRAW Update 15 3.4.3 PROXUSEFUL Update 15 3.4.4 PROXAVG Update 16 3.4.5 PROXDIFF Update 18 3.4.6 PROXSTAT Update 18 3.5 Host Operation 19 3.6 Operational Modes 20 3.6.1 Active 20 3.6.2 Doze 20 3.6.3 Sleep 20 3.6.4 TXEN Pin 20 4 I2C INTERFACE ........................................................................................................................... 21 4.1 Introduction 21 4.2 I2C Write 21 4.3 I2C Read 21 5 RESET ......................................................................................................................................... 23 5.1 Power-up 23 5.2 NRST Pin 23 5.3 Software Reset 24 6 INTERRUPT ................................................................................................................................. 25 Revision 4 February 4, 2014 2014 Semtech Corporation www.semtech.com 2