Block Diagram

Pin Description

Pin Name

I/O

Internal

Connection

Description

VSS

¾¾

Negative power supply, ground

RELAY

O

CMOS

RELAY drive output through an external NPN transistor, active high.

TRIAC

O

CMOS

TRIAC drive output

The output is a pulse output when active.

OSCD

I/O

PMOS IN

NMOS OUT

Output timing oscillator I/O

It is connected to an external RC to adjust output duration.

OSCS

I/O

PMOS IN

NMOS OUT

System oscillator I/O

OSCS is connected to an external RC to set the system frequency. The

system frequency is at 16kHz for normal application.

ZC

I

CMOS

Input for AC zero crossing detection

CDS

I

CMOS

CDS is connected to a CDS voltage divider for daytime/night

auto-detection. Low input to this pin can disable the PIR input. CDS a

Schmitt Trigger input with 5-second input debounce time.

MODE

I

CMOS

Operating mode selection input:

VDD: Output is always ON

VSS: Output is always OFF

Open: Auto detection

VDD

¾¾

Positive power supply

VEE

O

NMOS

Regulated voltage output

The output voltage is

-4V with respect to VDD.

RST

I

Pull-High

Chip reset input, active low

OP1P

I

PMOS

Noninverting input of OP1

OP1N

I

PMOS

Inverting input of OP1

OP1O

O

NMOS

Output of OP1

OP2P

I

PMOS

Noninverting input of OP2

OP2N

I

PMOS

Inverting input of OP2

OP2O

O

NMOS

Output of OP2

HT761X

Rev. 1.30

2

October 12, 2009

V o l t a g e

D i v i d e r

C o m p a r a t o r

O P 2 N

O P 2 P

O P 2 O

O P 1 P

O P 1 N

V E E

O P 1 O

L a t c h C i r c u i t

M o d e & C D S

C i r c u i t

R e g u l a t o r

C o n t r o l

C i r c u i t

O u t p u t C i r c u i t

R E L A Y

( T R I A C )

D e l a y C i r c u i t

C o u n t e r

C i r c u i t

Z e r o C r o s s

D e b o u n c e

D e l a y

O s c i l l a t o r

S y s t e m

O s c i l l a t o r

O S C D

O S C S

R S T

M O D E

C D S

V D D

V S S

Z C