HT7703
Touc h Dim mer
Pin Assignment Block Diagram
General Description
The HT7703 is a monolithic CMOS circuit de-
signed for brightness control of incandescent
lamps. The output of the HT7703 triggers a
triac connected in series with the lamp. There
are four specified levels of brightness through
which th e ou tp ut can b e ste pp ed . T h e s tep pi ng
function may be selected to operate in one of two
different modes by a MODE selector.
Features
•Wide operating voltage: 8V~12V
•Provided brightness control of incandescent
lamps without using mechanical switches
•Reducing the power dissipation
•Operating on 60/50 Hz line frequency
•Touch sensitive sensor input
1 26th Mar ’97
Pin Description
Pin No. Pin Name Descri ption
1 ZC Zero crossing input
2 OSC1 Oscillator 1
3 OSC2 Oscillator 2
4 SENSE Touch sense input
5 T1 Touch signal detector 1
6 T2 Touch signal detector 2
7 VDD Positive power supply
860/
50 60/50 Hz selection
9 MODE Mode selection
10 NC No connection
11 OUT Trigger output
12 NC No connection
13 VSS Negative power supply
14 PWR Power on reset
Electrical C hara cteristics
Symbol Parameter Test Conditi on Min. Typ. Max. Unit
VDD Condition
VDD Operation Voltage — — 8 10 12 V
IDD Operation Current 10V No load — 0.5 1 mA
VIL “Low” Input Vol t age 10V — — — 2 V
VIH “High” Input Voltage 10V — 8 — — V
RPU1 Pull-Up Resistance (60/50, MODE) 10V VI=0V 400 600 800 KΩ
RPU2 Pull-Up Resistance (PWR) 10V VI=0V 1 1.5 2 MΩ
IOL Sink C urrent (OUT) 10V VOUT=1V 25 80 — mA
IOH Source Current (OUT) 10V VOUT=9V –20 –60 — µA
FCLK Clock Frequency 10V Rosc=68K — 180K — Hz
HT7703
2 26th Mar ’97
Function Description
The operating mode of the circuit is selected by a MODE input as follows:
After powe r on, the initial state stays off. Following that, whenever the sensor plate is touched, the
output jumps to the next level of brightness.
Application Circuit
HT7703
3 26th Mar ’97
