Rev. 1.0 11/10

Copyright © 2010 by Silicon Laboratories

Si1102

Si1102

Features

Applications

Description

The Si1102 is a high-performance (0–50 cm) active proximity detector.

Because it operates on an absolute reflectance threshold principle, it avoids

the ambiguity of motion-based proximity systems.

The Si1102 consists of a patented, high-EMI immunity, differential photodiode

and a signal-processing IC with LED driver and high-gain optical receiver.

Proximity detection is based on measurements of reflected light from a

strobed, optically-isolated LED. The standard package for the Si1102 is an 8-

pin ODFN.

Functional Block Diagram

detector with a sensing range of up

to 50 cm

system power

strobe frequency

enables controlling devices to

avoid missing a detection

shielded packaging

–40 to +85 °C

and ultra-low power of 1 mA typical

saturated LED driver output

IR

Signal

processing

PRX

SREN

TXO

VSS

FR

LED

Drive

Shutdown

control

Oscillator

VDD

Infrared

emitter

Product

Case

Hi-Lo

Threshold

Output

Reflectance-Based Proximity Detection

U.S. Patent 5,864,591

U.S. Patent 6,198,118

U.S. Patent 7,486,386

Other patents pending

Pin Assignments

FR

VSS

TXO

TXGD

SREN

VDD

PRX

DNC

1

2

3

4

8

7

6

5

Si1102

ODFN