MPR081

Freescale Semiconductor Technical Data MPR081 Rev 0, 06/2007 Touch Pad Controller The MPR081 is a user interface controller which manages a 16-position rotary touch pad. The MPR081 uses an I2C interface to communicate with the host, which configures the operation, and an interrupt to advise the host of status changes. The interrupt output, IRQ, indicates that rotary status has changed since the MPR081 was last read. The maximum interrupt frequency can be limited to sacrifice system response time in favor of power consumption for systems that wake up out of sleep to respond to interrupts. Features • • • • • • • • • • • • • • • • • • • • • • • • 1.8 V to 3.6 V operation 150 µA average supply current (all touch pads being monitored) 1 µA standby current Supports a 16-position rotary interface Proprietary false touch rejection technology Ongoing pad analysis and detection not reset by EMI events Rotary data changes are delivered from a FIFO for shortest access time IRQ output advises when FIFO has data System can set interrupt behavior as immediate after event, or program a minimum time between successive interrupts Current rotary position is always available on demand for polling-based systems Sounder drive provides audible feedback to simulate mechanical key clicks Digital output (I2C with custom addressing) 16-pin QFN and TSSOP packages -40°C to +85°C operating temperature range Control Panels Switch Replacements Rotary and Linear Sliders Touch Pads Appliances PC Peripherals Access Controls MP3 Players Remote Controls Mobile Phones ORDERING INFORMATION Device Name MPR081Q MPR081EJ -40°C to +85°C Temperature Range Case Number 1679 (16-Lead QFN) 16-Positions 948F (16-Lead TSSOP) Rotary Slider MPR081 Touch Pad Controller Bottom View 16-LEAD QFN CASE 1679 16-LEAD TSSOP CASE 948F Top View RNE RSE RN RE Implementations RST IRQ VDD VSS RS MPR081Q RSW RW RNW Typical Applications SDA RST IRQ VDD VSS SCL SDA AD0 SOUNDER SOUNDER SCL AD0 RN RNE MPR081EJ RE RSE RS RSW RW RNW Figure 1. Pin Connections © Freescale Semiconductor, Inc., 2007. All rights reserved. Table 1. Absolute Maximum Ratings Rating Voltage (with respect to VSS) VDD All other pins Operating Temperature Range Storage Temperature Range Symbol — -0.3 to +3.8 VSS-0.3 to VDD+0.3 TA TSTG -40 to +85 -55 to +150 V V °C °C Value Unit Table 2. ESD and Latch-Up Protection Characteristics Rating Human Body Model Machine Model Charge Device Model Latch-Up Current at TA = 85°C Symbol HBM MM CDM — Value ±2000 ±200 ±500 ±100 Unit V V V mA Table 3. DC Characteristics (Typical Operating Circuit, V+ =1.8 V to 3.6 V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at V+ = 3.3 V, TA = +25°C.) Characteristic Operating Supply Voltage Standby Current (I2C Interface idle) Input High Voltage SDA, SCL Input Low Voltage SDA, SCL Input Leakage Current SDA, SCL Input Capacitance SDA, SCL Output Low Voltage SDA, IRQ VIH VIL IIH, IIL — VOL — — — — IOL = 6 mA 0.7 x VDD — — — — — — 0.025 — — — 0.35 x VDD 1 7 0.5 V V µA pF V Symbol V+ I+ Conditions — SCL and SDA at V+ or GND Min 1.8 TBD Typ Max 3.6 Units V µA Table 4. Interrupt IRQ Timing Characteristics (Typical Operating Circuit, V+ = 1.8 V to 3.6 V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at V+ = 3.3 V, TA = +25°C.) Characteristic IRQ Reset delay time from STOP IRQ Reset delay time from acknowledge Symbol tIP tIR Conditions CL ≤ 100 pF CL ≤ 100 pF Min — — Typ — — Max TBD TBD Units µs µs MPR081 2 Sensors Freescale Semiconductor Table 5. I2C AC Characteristics (Typical Operating Circuit, V+ = 1.8 V to 3.6 V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at V+ = 3.3 V, TA = +25°C.) Characteristic Serial Clock Frequency Bus Timeout Bus Free Time Between a STOP and a START Condition Hold Time, (Repeated) START Condition Repeated START Condition Setup Time STOP Condition Setup Time Data Hold Time Data Setup Time SCL Clock Low Period SCL Clock High Period Rise Time of Both SDA and SCL Signals, Receiving Fall Time of Both SDA and SCL Signals, Receiving Fall Time of SDA Transmitting Pulse Width of Spike Suppressed Capacitive Load for Each Bus Line Symbol fSCL FTIMEOUT tBUF tHD, STA tSU, STA tSU, STO tHD, DAT tSU, DAT tLOW tHIGH tR tF tF.TX tSP Cb Min — — 1.3 0.6 0.6 0.6 — 100 1.3 0.7 — — — — — Typ — 31.25 — — — — — — — — 20+0.1Cb 20+0.1Cb 20+0.1Cb 50 — Max 400 — — — — — 0.9 — — — 300 300 250 — 400 Units kHz ms µs µs µs µs µs ns µs µs ns ns ns ns pF MPR081 Sensors Freescale Semiconductor 3 Table 6. Pin Description Pin 1 2 3 4 5 6 7 8 9 - 16 PAD Name RST IRQ VDD VSS SCL SDA AD0 SOUNDER RNW, RW, RSW, RS, RSE, RE, RNE, RN Exposed Pad Function Reset Input. Active low clears the 2-wire interface and puts the device in the same condition as power-up reset. Interrupt Output. IRQ is the active-low open-drain interrupt output signalling new events. Positive Supply Voltage Bypass VDD to VSS with a 0.1µF ceramic capacitor Ground I²C-Compatible Serial Clock Input I²C-Compatible Serial Data I/O Address input 0. Connect to VSS to select device slave address 0x4C. Connect to VDD to select device slave address 0x4D. Sounder driver output. Connect a piezo-ceramic sounder from this output to ground. Output is push-pull. Rotary Touch Inputs. Connect the 8 inputs to a 16-position rotary sensor. Exposed Pad on Package Underside (QFN only). Connect to VSS. RNE RSE RN RE RST IRQ 1 2 3 4 5 6 7 8 16 15 14 RN RNE RE RSE RS RSW RW RNW 16 RST IRQ VDD VSS 15 14 13 12 RS 11 RSW 10 RW 9 RNW 1 2 3 4 5 SCL VDD VSS SCL SDA AD0 SOUNDER MPR081Q MPR081EJ 13 12 11 10 9 6 SDA 7 AD0 8 SOUNDER Figure 2. MPR081 Pinout MPR081 4 Sensors Freescale Semiconductor CLEAR SDA SCL RST AD0 I2C SERIAL INTERFACE EMI BURST/NOISE REJECT FILTER RATE CAPACITANCE MEASUREMENT A.F.E. SET CONFIGURATION AND STATUS REGISTERS IRQ INTERRUPT CONTROLLER MAGNITUDE COMPARATOR AND RECALIBRATOR MASKS NNW NW NWW W SWW SW SSW N NNE NE NEE E SEE SE ROTARY POSITION ROTARY POSITION DECODER 8 8 8 S SSE SOUNDER SOUNDER CONTROLLER 16 POSITION ROTARY Figure 3. Internal Block Diagram MPR081 Sensors Freescale Semiconductor 5 DETAILED DESCRIPTION FUNCTIONAL OVERVIEW The MPR081user interface controller monitors various combinations of capacitive touch pads, capacitive sliders, capacitive rotaries, and mechanical keys. The device includes a piezo buzzer driver which generates key click sounds to provide audible feedback of pad touches and/or Table 7. MPR08 Family Overview Product MPR081 MPR082 2 key presses. The MPR081 also uses a standardized user register set to configure the part on power up, and to read pad, slider and key status. The commonality between products in the MPR08 family of controllers simplifies migration between parts. Bus I C with RST I2C with RST Sounder Yes Yes Rotary Slider 16-Positions — Touch Pad Array — 20 Pads(1) Main Attribute Highest resolution rotary Two independent arrays of 10 touch pads 1. The 20 pads are implemented by two independent arrays of 10 touch pads. A quick word on terminology: – A mechanical keyswitch is a switch containing, at its simplest, two contacts which have either a high (>10 MΩ) or a low resistance (