Rainbow Electronics AT42QT1012 - Manual (Page 3)

3
9543CS–AT42–02/10
AT42QT1012
1.3 Schematic
Figure 1-1. Basic Circuit Configuration
(active high output, toggle on/off, no auto switch off)
2. Overview of the AT42QT1012
2.1 Introduction
The AT42QT1012 (QT1012) is a single key device featuring a touch on/touch off (toggle) output
with a programmable auto switch-off capability.
The QT1012 is a digital burst mode charge-transfer (QT ™ ) sensor designed specifically for touch
controls. It includes all hardware and signal processing functions necessary to provide stable
sensing under a wide variety of changing conditions; only low cost, noncritical components are
required for operation. With its tiny low-cost SOT-23 package, this device can suit almost any
product needing a power switch or other toggle-mode controlled function, especially power
control of small appliances and battery-operated products.
A unique “green” feature of the QT1012 is the timeout function, which can turn off power after a
specified time delay ranging from minutes to an hour.
Like all QTouch ® devices, the QT1012 features automatic self-calibration, drift compensation,
and spread-spectrum burst modulation in order to provide for the most reliable touch sensing
possible.
VDD
TIME
VSS
2
6
5
OUT
1
Rop
VDD
CS
SNSK
SNS
4
3
RS
Note: bypass capacitor to be tightly
wired between VDD and VSS and
kept close to pin 5.
SENSE
ELECTRODE