SX8661Z datasheet(22/87 Pages) SEMTECH

22 / 87 page

ADVANCED COMMUNICATIONS & SENSING

DATASHEET

Revision v4.0, February 2016

www.semtech.com

SX8661Z

Low Power, Capacitive Button Touch and Proximity Controller

(8 sensors) with LED Drivers and Analog Output

3.10 Processing

The first processing step of the raw ticks, coming out of the ASI, is low pass filtering to obtain an estimation of the

average capacitance: tick-ave (see Figure 17).

This slowly varying average is important in the detection of slowly changing environmental changes.

ticks (raw)

compensation DCV

ASI

processing

low pass

tick-diff

tick-ave

processing

GPIO

controller

PWM LED

controller

I2C

SPM

Figure 17

Processing

The difference of the tick average and the raw ticks, tick-diff, is a good estimation of rapid changing input

capacitances.

The tick-diff, tick-ave and the configuration parameters in the SPM are then processed and determines the sensor

information, I2C registers status and PWM control.

3.11 Configuration

Figure 18 shows the building blocks used for configuring the SX8661Z.

micro

processor

MTP

NVM

I2C

SX8661Z

HOST

SPM

QSM

Figure 18

Configuration

The default configuration parameters of the SX8661Z are stored in the Quick Start Memory (QSM). This

configuration data is setup to a very common application for the SX8661Z with 8 buttons. Without any

programming or host interaction the SX8661Z will start up in the Quick Start Application.

The QSM settings are fixed and cannot be changed by the user.

SX8661Z Datasheet(PDF) 22 Page - Semtech Corporation

SX8661Z Datasheet(HTML) 22 Page - Semtech Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87

Datasheet Download

Link URL