HT761X

Rev. 1.30

4

October 12, 2009

OSCD

OSCD is an output timing oscillator input pin. It is con-

nected to an external RC to obtain the desired output

turn-on duration. Variable output turn-on durations can

be achieved by selecting various values of RC or using a

variable resistor.

RELAY (TRIAC)

RELAY is an output pin set as a RELAY driving (active

high) output for the HT761xA, or as a TRIAC driving (ac-

tive low) output for the HT761xB.

The output active duration is controlled by the OSCD os-

cillating period.

HT761xA

HT761xB

OUTPUT

RELAY

TRIAC

CDS

CDS is a CMOS Schmitt Trigger input structure. It is

used to distinguish between day time and night time.

When the input voltage of CDS is high the PIR input is

enabled. On the other hand, when CDS is low the PIR

input is disabled. The input disable to enable debounce

time is 5 seconds. Connect this pin to VDD when this

function is not used. The CDS input is ignored when the

output is active.

CDS

Status

PIR

LOW

Day Time

Disabled

HIGH

Night

Enabled

MODE

MODE is a tristate input pin used to select the operating

mode.

MODE

Status

Operating

Mode

Description

VDD

ON

Output is always ON:

RELAY outputs high for relay driving.

TRIAC pulse train output is syn-

chronized by ZC for triac driving.

VSS

OFF

Output is always OFF:

RELAY outputs low for relay driving.

TRIAC outputs high for triac driving.

Open

AUTO

Outputs remain in the off state until

activated by a valid PIR input trigger

signal. When working in the AUTO

mode, the chip allows override con-

trol by switching the ZC signal.

O S C D

Output Timing Oscillator

1

f

´ 21504

< 5 s e c

d i s a b l e

C D S

P I R

e n a b l e

5 s e c

e n a b l e

R S T B

Z C

T e s t

e n a b l e

C o m p a r a t o r

o u t p u t

R E L A Y

( T R I A C )

1 0 s

4 0 s w a r m - u p t i m e

< 3 s

O F F / O N o n e o r t w o t i m e s b y m a s k o p t i o n

> 0 . 3 4 s

O N

f l a s h o r n o t b y m a s k o p t i o n

O N

O N

O N

> 3 2 s

*

f l a s h 3 t i m e s i n 1 H z

O F F

#

2 s

2 s

2 s

* : f l a s h 3 t i m e s a t a 1 H z r a t e

f l a s h o r n o t b y m a s k o p t i o n

# : f l a s h 3 t i m e s a t a 2 H z r a t e

f l a s h o r n o t b y m a s k o p t i o n

2 s

2 s