+

E+

D

2

0.129 (3.3)

0.119 (3.0)

0.433 (11.0)

0.422 (10.7)

0.315 (8.0)

0.110 (2.8)

0.091 (2.3)

1

3

4

0.020 (0.51) (SQ)

0.472 (12.0)

0.457 (11.6)

0.249 (6.35)

0.243 (6.15)

0.39 (1.00)

0.34 (0.85)

0.103 (2.60) NOM

0.125 (3.2)

0.119 (3.0)

Ø 0.133 (3.4)

Ø 0.126 (3.2)

(2X)

0.755 (19.2)

0.745 (18.9)

L

C

CL

L

C

Optical

CL

0.972 (24.7)

0.957 (24.3)

.295 (7.5)

.272 (6.9)

PIN 1 ANODE

PIN 2 CATHODE

PIN 3 COLLECTOR

PIN 4 EMITTER

PACKAGE DIMENSIONS

FEATURES

• Opaque housing

• Low cost

• .035” apertures

NOTES:

1. Dimensions for all drawings are in inches (mm).

2. Tolerance of ± .010 (.25) on all non-nominal dimensions

unless otherwise specified.

PHOTOTRANSISTOR

OPTICAL INTERRUPTER SWITCH

DESCRIPTION

The H21A series are gallium arsenide infrared emitting diode coupled with a silicon photodarlington in a plastic housing. The

packaging system is designed to optimize the mechanical resolution, coupling efficiency, ambient light rejection, cost and

reliability. The gap in the housing provides a means of interrupting the signal with an opaque material, switching the output

from an “ON” to an “OFF” state.

4

3

1

2

SCHEMATIC



 2001 Fairchild Semiconductor Corporation

DS300291

6/05/01

1 OF 4

www.fairchildsemi.com

H21A4

H21A5

H21A6