SX8661 Datasheet, PDF (1/88 Pages) Semtech Corporation – Low Power, Capacitive Button Touch and Proximity Controller

SX8661
Low Power, Capacitive Button Touch and Proximity Controller
(8 sensors) with LED Drivers and Analog Output
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
GENERAL DESCRIPTION
The SX8661 is an ultra low power, fully integrated 8-
channel solution for capacitive touch-button and
proximity detection applications. Unlike many
capacitive touch solutions, the SX8661 features
dedicated capacitive sense inputs (that requires no
external components) in addition to 8 general
purpose I/O ports (GPIO). Each of the 8 on-chip
GPIO/LED driver is equipped with independent PWM
source for enhanced visual effect such as dimming,
and breathing.
The SX8661 includes a capacitive 10 bit ADC analog
interface with automatic compensation up to 100pF.
The high resolution capacitive sensing supports a
wide variety of touch pad sizes and shapes and
allows capacitive buttons to be created using thick
overlay materials (up to 5mm) for an extremely
robust and ESD immune system design.
The SX8661 incorporates a versatile firmware that
was specially designed to simplify capacitive touch
solution design and offers reduced time-to-market.
Integrated multi-time programmable memory
provides the ultimate flexibility to modify key firmware
parameters (gain, threshold, scan period, auto offset
compensation) in the field without the need for new
firmware development.
The SX8661 supports the 400 kHz I²C serial bus
data protocol and includes a field programmable
slave address. The tiny 4mm x 4mm footprint makes
it an ideal solution for portable, battery powered
applications where power and density are at a
premium.
TYPICAL APPLICATION CIRCUIT
KEY PRODUCT FEATURES
 Complete 8 Sensors Capacitive Touch-Button Solution
o Up to 8 LED Drivers for individual Visual Feedback with
Auto Lightening
o Configurable Single or Continuous Fading Mode
o 256 steps PWM Linear and Logarithmic control
 Proximity Sensing up to several centimetres
 High Resolution Capacitive Sensing
o Up to 100pF of Offset Cap. Compensation at Full
Sensitivity
o Capable of Sensing up thru 5mm thick Overlay Materials
 Up to 2 Analog Output Interfaces (AOI-A and AOI-B)
o Enable button detection thru host’s ADC
 Support of buzzer for audible feedback
 User-selectable Button Reporting Configuration
o Report Single or Report Strongest
 Extremely Low Power
o 8uA (typ) in Sleep Mode
o 70uA (typ) in Doze Mode (195ms)
o 200uA (typ) in Active Mode (30ms)
 Programmable Scanning Period from 15ms to several seconds
 Auto Offset Compensation
o Eliminates false triggers due to environmental factors
(temperature, humidity)
o Initiated on power-up and configurable intervals
 Multi-Time In-Field Programmable Firmware Parameters
for Ultimate Flexibility
o On-chip user programmable memory for fast, self
contained start-up
 No External Components per Sensor Input
 Internal Clock Requires No External Components
 Differential Sensor Sampling for Reduced EMI
 Optional 400 KHz I²C Interface with Programmable Address
 -40°C to +85°C Operation
APPLICATIONS
 LCD TVs, Monitors
 White Goods
 Notebook/Netbook/Portable/Handheld computers
 Consumer Products, Instrumentation, Automotive
 Mechanical Button Replacement
ORDERING INFORMATION
Part Number Temperature
Range
Package
SX8661I07AULTRT¹ -40°C to +85°C Lead Free MLPQ-UT28
1 _{3000 Units/reel}
* This device is RoHS/WEEE compliant and Halogen Free
Revision v3.2, January 2011
© 2011 Semtech Corp.
1
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