H21AX

Opaque Slotted Photointerrupter

The H21AX is a opaque slotted photointerrupter from Isocom. View the full H21AX datasheet below including key specifications, absolute maximum ratings.

H21AX shares its datasheet with H21A1, whose page lists every part number it covers.

Official H21AX datasheet (PDF) — the source this page was extracted from.

Manufacturer

Isocom

H21AX Key Specifications

Parameter	Value
China RoHS	Compliant
Collector Emitter Breakdown Voltage	30 V
Contact Plating	Tin
Collector Current (Max)	3 mA
Current - DC Forward (If) (Max)	60 mA
Dark Current	100 nA
Forward Current	50 mA
Introduction Date	1987-08-11
Lead Free	Lead Free
Lifecycle Status	Production (Last Updated: 1 month ago)
Max Operating Temperature	85 °C
Min Operating Temperature	-25 °C
Mounting Type	Through Hole, Flange
Number of Circuits	1
Operating Temperature	-55°C ~ 100°C
Output Configuration	Phototransistor
Package / Case	Slotted, PC Pins
Packaging	Tube
Power Dissipation	75 mW
REACH SVHC	Affected
Response Time	8µs, 50µs
RoHS	Compliant
Sensing Distance	0.118" (3mm)
Sensing Method	Through-Beam
Standard Pack Qty	50
Collector-Emitter Breakdown Voltage	30 V

H21AX Overview

Part: H21A1 — Isocom Components

Type: Opaque Slotted Photointerrupter (GaAs IR LED + NPN Phototransistor)

Description: Single-channel opaque photointerrupter with a 3 mm gap between a GaAs infrared LED and an NPN silicon phototransistor, with 30 V VCEO and a minimum on-state collector current of 0.15 mA at IF = 5 mA (H21A1).

Operating Conditions:

Supply voltage: not applicable
Operating temperature: -25 to 85 °C
Forward current (LED): up to 50 mA (absolute maximum)

Absolute Maximum Ratings:

Input forward current: 50 mA
Input reverse voltage: 5 V
Input power dissipation: 75 mW
Collector current: 20 mA
Collector-emitter voltage: 30 V
Emitter-collector voltage: 5 V
Output power dissipation: 100 mW
Storage temperature: -55 to 100 °C
Lead soldering temperature (10 s): 260 °C

Key Specs:

Forward voltage VF: 1.2 V typ, 1.6 V max (IF = 20 mA)
Reverse current IR: 100 μA max (VR = 5 V)
Collector-emitter dark current ICEO: 100 nA max (VCE = 10 V)
On-state collector current IC(ON), H21A1/H22A1: 0.15 mA min (IF = 5 mA, VCE = 5 V)
Collector-emitter saturation voltage VCE(SAT): 0.4 V max (IF = 20 mA, IC = 0.25 mA)
Output rise time tr: 3 μs typ, 15 μs max (VCE = 5 V, IC = 2 mA, RL = 100 Ω)
Output fall time tf: 4 μs typ, 20 μs max (same conditions)

Features:

High gain
3 mm gap between LED and detector
Polycarbonate case protects against ambient light
Pb free and RoHS compliant
Safety approvals pending
H21Ax provides flanges for screw mounting

Applications:

Copiers, printers, facsimiles
Record players, cassette decks
Optoelectronic switches

Package:

PWB-mount polycarbonate housing with screw-mount flanges (H21A series)
Bulk packing, 500 pcs

H21AX Features

High Gain
3mm Gap between LED and Detector
Polycarbonate Case Protection against Ambient Light
Pb Free and RoHS Compliant
Safety Approvals Pending

H21AX Applications

Copiers, Printers, Facsimiles
Record Players, Casette Decks
Optoelectronic Switches

H21AX Absolute Maximum Ratings

Stresses exceeding the absolute maximum ratings can cause permanent damage to the device.

Exposure to absolute maximum ratings for long periods of time

Variants on the same datasheet

These parts have exact links to the same datasheet. They are candidates to compare, not verified drop-in replacements; check package, pinout and electrical limits.

Part Number	Manufacturer	Package
H21A1	Isocom	Slotted, PC Pins
H21A2	onsemi	Slotted, PC Pins
H21A3	onsemi	Slotted, PC Pins
H22A1	Isocom	Slotted, PC Pins
H22A2	onsemi	Slotted, PC Pins
H22A3	onsemi	Slotted, PC Pins

More datasheets

All Isocom datasheets (3)

Data on this page is extracted from publicly available manufacturer datasheets using automated tools including AI. It may contain errors or omissions. Always verify specifications against the official manufacturer datasheet before making design or purchasing decisions. See our Terms of Service. Rights holders can submit a takedown request.

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