iC-OW

INCREMENTAL OPTO ENCODER

Rev A1, Page 2/7

B-

A+

B+

A-

Z

TIP

TIN

NTEST

AGND

GND

VCC

A

B

Z

NERR

LED

CLR

IZ

ILR

DESCRIPTION

iC-OW is an evaluator iC for optical incremental linear and rotary motion sensors, such as glass scales or

shaft encoders, for example. A photodiode array, amplifiers, comparators and TTL-compatible push-pull

output drivers are integrated monolithically.

Two tracks, A and B, are evaluated differentially, with index track Z as constant light. The integrated LED

current control with a driver stage enables a transmitter LED with a series resistor to be directly connected to

the device and ensures a constant optical receive power. Two external resistors are used to set the

comparator threshold of the relative index track and to determine the receive photocurrents.

The internal logical AND operation of index track Z to tracks A and B can be switched off for adjustment.

A monitoring circuit generates an error message when the LED current control range is violated. The error

output, designed as an open collector, is low active and functions simultaneously as an input which can turn

off the AND operation of the index track.

All pins are protected against destruction by ESD. The outputs are short-circuit-proof.

CHIP LAYOUT

PAD DESCRIPTION

Name

Function

VCC

+5V Supply Voltage

A

Track A Output

B

Track B Output

Z

Track Z Output

NERR

Error Output (low active) / AND Gate

Disable Input

LED

LED Current Control Output

CLR

Capacitor for LED Current Control

IZ

Index Track Threshold Adjust

ILR

LED Current Control Setup

GND

Ground

AGND

Reference Ground for

ILR, IZ, CLR circuitry

TIP

Positive Test Aid Input

TIN

Negative Test Aid Input

NTEST

Test Enable Input, low active