SX8635 Low Power, Capacitive Button and Wheel Touch Controller (12 sensors) with Enhanced LED Drivers and Proximity Sensing ADVANCED COMMUNICATIONS & SENSING DATASHEET GENERAL DESCRIPTION KEY PRODUCT FEATURES The SX8635 is an ultra low power, fully integrated Complete Twelve Sensors Capacitive Touch Controller for 12-channel solution for capacitive touch-buttons and Buttons and Wheel wheel with proximity detection applications. Unlike Pre-configured for 6 Buttons and a Wheel many capacitive touch solutions, the SX8635 8 LED Drivers with Individual Intensity, Fading Control features dedicated capacitive sense inputs (that and Autolight Mode requires no external components) in addition to 8 general purpose I/O ports (GPIO). Each GPIO is 256 steps PWM Linear and Logarithmic control typically configured as LED driver with independent Proximity Sensing up to several centimetres PWM source for enhanced lighting control such as High Resolution Capacitive Sensing intensity and fading. Up to 100pF of Offset Capacitance Compensation at Full Sensitivity The SX8635 includes a capacitive 10 bit ADC analog Capable of Sensing through Overlay Materials up to interface with automatic compensation up to 100pF. 5mm thick The high resolution capacitive sensing supports a Extremely Low Power Optimized for Portable Application wide variety of touch pad sizes and shapes and allows capacitive buttons to be created using thick 8uA (typ) in Sleep Mode overlay materials (up to 5mm) for an extremely 80uA (typ) in Doze Mode (Scanning Period 195ms) robust and ESD immune system design. 220uA (typ) in Active Mode (Scanning Period 30ms) Programmable Scanning Period from 15ms to 1500ms The SX8635 incorporates a versatile firmware that Auto Offset Compensation was specially designed to simplify capacitive touch Eliminates False Triggers due to Environmental solution design and offers reduced time-to-market. Factors (Temperature, Humidity) Integrated multi-time programmable memory Initiated on Power-up and Configurable Intervals provides the ultimate flexibility to modify key firmware parameters (gain, threshold, scan period, auto offset Multi-Time In-Field Programmable Firmware Parameters compensation ) in the field without the need for for Ultimate Flexibility new firmware development. On-chip user programmable memory for fast, self contained start-up The SX8635 supports the 400 kHz IC serial bus Smar Wake-up Sequence for Easy Activation from Doze data protocol and includes a field programmable No External Components per Sensor Input slave address. The tiny 5mm x 5mm footprint makes Internal Clock Requires No External Components it an ideal solution for portable, battery powered Differential Sensor Sampling for Reduced EMI applications where power and density are at a premium. 400 KHz Fast-Mode IC Interface with Interrupt -40C to +85C Operation TYPICAL APPLICATION CIRCUIT APPLICATIONS Notebook/Netbook/Portable/Handheld computers d7 Cell phones, PDAs cap0 d0 d6 cap1 Consumer Products, Instrumentation, Automotive d1 gnd cap2 SX8635 Mechanical Button Replacement d2 cap3 analog clock PWM gpio5 d3 sensor generation LED d5 cap4 interface RC controller gpio4 d4 ORDERING INFORMATION d4 cap5 d5 power management gpio3 d3 Part Number Temperature Package gpio2 d2 micro GPIO processor controller Range gnd cap6 1 d6 d7 cap7 RAM NVM gpo1 d1 SX8635I05AWLTRT -40C to +85C Lead Free MLPQ-W32 cap8 gpio0 d0 ROM I2C cap9 1 bottom plate 3000 Units/reel cap10 cap11 * This device is RoHS/WEEE compliant and Halogen Free HOST Revision 8 1, December 15 2010 Semtech Corp. www.semtech.com 1 proximity cn vana cp resetb vdd gnd intb vdig gpio7 scl gpio6 sda SX8635 Low Power, Capacitive Button and Wheel Touch Controller (12 sensors) with Enhanced LED Drivers and Proximity Sensing ADVANCED COMMUNICATIONS & SENSING DATASHEET Table of Contents GENERAL DESCRIPTION ........................................................................................................................ 1 TYPICAL APPLICATION CIRCUIT ............................................................................................................ 1 KEY PRODUCT FEATURES..................................................................................................................... 1 APPLICATIONS ....................................................................................................................................... 1 ORDERING INFORMATION...................................................................................................................... 1 1 GENERAL DESCRIPTION ............................................................................................................... 4 1.1 Pin Diagram 4 1.2 Marking information 4 1.3 Pin Description 5 1.4 Simplified Block Diagram 6 1.5 Acronyms 6 2 ELECTRICAL CHARACTERISTICS ................................................................................................. 7 2.1 Absolute Maximum Ratings 7 2.2 Recommended Operating Conditions 7 2.3 Thermal Characteristics 7 2.4 Electrical Specifications 8 3 FUNCTIONAL DESCRIPTION ........................................................................................................ 10 3.1 Quickstart Application 10 3.2 Introduction 10 3.2.1 General 10 3.2.2 GPIOs 11 3.2.3 Parameters 11 3.2.4 Configuration 11 3.3 Scan Period 12 3.4 Operation modes 12 3.5 Sensors on the PCB 14 3.6 Button and Wheel Information 15 3.6.1 Button Information 15 3.6.2 Wheel Information 15 3.7 Analog Sensing Interface 17 3.8 Offset Compensation 18 3.9 Processing 19 3.10 Configuration 19 3.11 Power Management 21 3.12 Clock Circuitry 21 3.13 I2C interface 21 3.14 Reset 22 3.14.1 Power up 22 3.14.2 RESETB 22 3.14.3 Software Reset 23 3.15 Interrupt 24 3.15.1 Power up 24 3.15.2 Assertion 24 3.15.3 Clearing 24 Revision 8 1, December 15 2010 Semtech Corp. www.semtech.com 2