IC FOR OPTO DETECTOR

AM 336

analog microelectronics

February 2005

4/12

FUNCTIONAL DIAGRAM

FUNCTIONAL DESCRIPTION

GENERAL:

The AM 336 is designed for proximity and barrier applications with the possibility of external

synchronisation (mode selection by Pin P/B).

The circuit contains different functional modules.

Oscillator:

Oscillator thresholds refer to VCC/2, driver output for IR–LED, emitting–pulse length and duty

cycle adjusted by external components RO and CO.

Amplifier:

Current to voltage converter, ambient light rejection.

Csc

+

Rtd2

+

Rtd1

Ro

+

C

+

IRD

BARRIER

PROXIMITY

+

VZ

VCC

short circuit

pulse

generatation

CSC

VS

+

RS

current

regulation

Rs

+

QC

+

T1

T2

T

D

Re

+

Co

FO

P/B

:128

:4

QO

+

FFA

FFB

D Q

A

A

Rtb

Rta

VTA

+

Rin

IND

Cin

Ra

Ca

ALR

OUTA

Rb

B

I(Rd,Rh)

VTB

VR

D Q

B

A B SC LED

T1 T2

+

+

LED

X X L

T1

L

L H

L

L H H

T2

H H

H

H

B

A

SC

+

GN

INA

Rd

Rh

RH

RD

+

Figure 1: Functional circuit