SMSC CAP1088 8路容性触摸传感器参考设计

SMSC公司的CAP1088是带LED驱动器的8路容性触摸传感器,包括有可编程灵敏度的8路单独的容性触摸传感器,每个传感器可自动进行重新校准,以补偿环境的变化.主要应用在台式计算机和笔记本电脑,LCD监视器,打印机和家用电器.本文介绍了CAP1088主要特性,方框图, 系统方框图以及容性触摸传感器参考设计电路图.

8 Channel Capacitive Touch Sensor with 8 LED Drivers

The CAP1088 is a multiple channel Capacitive Touch sensor with multiple power LED drivers. It contains eight (8) individual Capacitive Touch sensor inputs with programmable sensitivity for use in touch sensor applications. Each sensor automatically recalibrates to compensate for gradual environmental changes.

The CAP1088 also contains eight (8) LED drivers that offer full-on / off, variable rate blinking, dimness controls, and breathing. Each of the LED drivers may be linked to one of the sensors to be actuated when a touch is detected. As well, each LED driver may be individually controlled via a host controller.

The CAP1088 offers multiple power states operating at low quiescent currents.

During the Standby mode of operation, one or more Capacitive Touch Sensors are active and all LEDs may be used. If a touch is detected, then it will wake the system using the WAKE/SPI_MOSI pin.

The Deep Sleep mode of operation is the lowest power state available drawing 3uA of current. During this mode, no sensors are activethough all LEDs may be used. Driving the WAKE/SPI_MOSI pin or communications will wake the device.

CAP1088主要特性:

□ Eight (8) Capacitive Touch Sensor Inputs

— Programmable sensitivity

— Automatic recalibration

— Individual thresholds for each button

□ Flexible Capacitive Touch Sense algorithm

□ Multiple Communication interfaces

— SMBus / I2C compliant interface

— SMSC BC-Link interface

— SPI communications

— Pin selectable communications protocol and multiple slave addresses (SMBus / I2C only)

□ Low Power operation

— 3uA quiescent current in Deep Sleep

— Samples one or more channels in Standby

□ Eight (8) LED Driver Outputs

— Open Drain or Push-Pull

— Programmable blink, breathe, and dimness controls

— Can be linked to Capacitive Touch Sensors

□ Dedicated Wake output flags touches in low power mode

□ System RESET pin

□ Available in 24-pin 4mm x 4mm RoHS compliant QFN package

CAP1088应用:

□ Desktop and Notebook PC’s

□ LCD Monitors

□ Printers

□ Appliances

图1.CAP1088方框图

图2.CAP1088系统方框图

CAP1088容性触摸传感器参考设计


图3.容性触摸传感器参考设计电路图