SX8643 Ultra Low Power, Capacitive Button Touch Controller (12 sensors) with Enhanced LED Drivers ADVANCED COMMUNICATIONS & SENSING DATASHEET GENERAL DESCRIPTION KEY PRODUCT FEATURES The SX8643 is an ultra low power, fully integrated Complete twelve Sensors Capacitive Touch Controller for 12-channel solution for capacitive touch-buttons and Buttons applications. Unlike many capacitive touch solutions, Pre-configured for eight Buttons the SX8643 features dedicated capacitive sense Eight LED Drivers with Individual Intensity, Fading inputs (that requires no external components) in Control and Autolight Mode addition to 8 general purpose I/O ports (GPIO). Each GPIO is typically configured as LED driver with 256 steps PWM Linear and Logarithmic control independent PWM source for enhanced lighting High Resolution Capacitive Sensing control such as intensity and fading. Up to 100pF of Offset Capacitance Compensation at Full Sensitivity The SX8643 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 8uA (typ) in Sleep Mode allows capacitive buttons to be created using thick 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 SX8643 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 Multi-Time In-Field Programmable Firmware Parameters parameters (gain, threshold, scan period, auto offset 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 SX8643 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 400 KHz Fast-Mode IC Interface with Interrupt premium. -40C to +85C Operation TYPICAL APPLICATION CIRCUIT APPLICATIONS Notebook/Netbook/Portable/Handheld computers Cell phones, PDAs Consumer Products, Instrumentation, Automotive Mechanical Button Replacement ORDERING INFORMATION Part Number Temperature Package Range 1 SX8643I05AWLTRT -40C to +85C Lead Free MLPQ-W32 1 3000 Units/reel * This device is RoHS/WEEE compliant and Halogen Free Revision 7 5, February 10 2010 Semtech Corp. www.semtech.com 1 SX8643 Ultra Low Power, Capacitive Button Touch Controller (12 sensors) with Enhanced LED Drivers 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 Information 14 3.6.1 Button Information 14 3.7 Analog Sensing Interface 14 3.8 Offset Compensation 15 3.9 Processing 17 3.10 Configuration 17 3.11 Power Management 19 3.12 Clock Circuitry 19 3.13 I2C interface 19 3.14 Reset 20 3.14.1 Power up 20 3.14.2 RESETB 20 3.14.3 Software Reset 21 3.15 Interrupt 22 3.15.1 Power up 22 3.15.2 Assertion 22 3.15.3 Clearing 22 3.15.4 Example 23 Revision 7 5, February 10 2010 Semtech Corp. www.semtech.com 2