preliminary

preliminary

iC-OG

8-BIT DIFFERENTIAL SCANNING OPTO ENCODER

Rev D1, Page 2/10

DESCRIPTION

iC-OG is an optoelectronic sensor IC for linear and

rotary motion control systems, such as glass scales

or shaft encoders, for example.

Photodiodes,

amplifiers,

comparators and TTL-

compatible push-pull output drivers are integrated

monolithically. Each of the 8 tracks is evaluated dif-

ferentially; 3 tracks feature additional high-side and

low-side current sources and output a push-pull ana-

log signal.

The integrated LED current control with its driver

stage connects to the encoder LED and ensures a

constant optical received power. A series resistor

is used here as current limiter, and thus defines the

control’s operating range. If the LED current control

reaches operating limits, error message output NER

indicates a low signal (LED end-of-life, or open loop

conditions).

Tracks 0 and 1 with their differential scanning pho-

todiodes provide a sum current for LED controlling,

averaged by the capacitor at pin CSR. The sum cur-

rent is compared with the setpoint adjusted by the

external resistor at pin ISET.

Two test pins (TIP, TIN) allow a full test of all chip

functions to be carried out excluding the photodiodes.

All push-pull and analog outputs are protected

against ESD and short-circuit damage.

The error

message output NER is also protected against short-

circuiting and can be used in bus systems due to its

open-collector output.

PACKAGES

PAD LAYOUT / CHIP LAYOUT

Chip size 3.05 mm x 5.1 mm

PAD FUNCTIONS

No.

Name Function

See pin functions.

Notes

The optical sensor axis is not exactly

the chip center.