CAP1128 datasheet(22/75 Pages) MICROCHIP

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CAP1128

DS00001622B-page 22

 2015 Microchip Technology Inc.

5.0

GENERAL DESCRIPTION

The CAP1128 is a multiple channel Capacitive Touch sensor with multiple power LED drivers. It contains eight (8) indi-

vidual capacitive touch sensor inputs with programmable sensitivity for use in touch sensor applications. Each sensor

input automatically recalibrates to compensate for gradual environmental changes.

The CAP1128 also contains two (2) low side (or push-pull) LED drivers that offer full-on / off, variable rate blinking, dim-

ness controls, and breathing. Each of the LED drivers may be linked to one of the sensor inputs to be actuated when a

touch is detected. As well, each LED driver may be individually controlled via a host controller.

Finally, the device contains a dedicated RESET pin to act as a soft reset by the system.

The CAP1128 offers multiple power states. It operates at the lowest quiescent current during its Deep Sleep state. In

the low power Standby state, it can monitor one or more channels and respond to communications normally. The device

contains a wake pin (WAKE/SPI_MOSI) output to wake the system when a touch is detected in Standby and to wake

the device from Deep Sleep.

The device communicates with a host controller using the SPI bus, or via SMBus / I2C. The host controller may poll the

device for updated information at any time or it may configure the device to flag an interrupt whenever a touch is

detected on any sensor pad.

A typical system diagram is shown in Figure 5-1.

CAP1128 Datasheet(PDF) 22 Page - Microchip Technology