4N35 — Datasheet Summary, Specs & Alternatives

01 — Overview

This Vishay datasheet covers the 4N35, 4N36, and 4N37 optocouplers, which feature a phototransistor output with an exposed base pin. Designed for isolating digital signals between high-voltage and low-voltage circuits, these components support applications like AC mains detection, relay driving, and switch-mode power supply feedback. Key electrical parameters include a maximum isolation test voltage of 5000 V RMS, a typical current transfer ratio (CTR) exceeding 100%, a forward input voltage of 1.5 V at 10 mA, and a collector-emitter breakdown voltage of 70 V. The devices operate within a temperature range of -55 to +100 °C and are available in a standard dual-in-line 6-pin package.

02 — Key specifications

Datasheet parameters

Parameter	Min	Typ	Max	Conditions
output current	—	—	50 mA	mA
rds on	—	—	1.01 kOhm	VIO = 500 V, Tamb = 25 °C
forward voltage	900 mV	1.3 V	1.7 V	IF = 10 mA, Tamb = - 55 °C
operating temperature	-55 °C	—	100 °C
power dissipation	—	—	70 mW	mW
reverse voltage	—	—	6 V	V
forward current	—	—	50 mA	mA
reverse leakage current	—	100 nA	10 µA	VR = 6 V
breakdown voltage ds	—	—	70 V	V
isolation voltage	—	—	5 kV	VRMS
junction capacitance	—	50 pF	—	VR = 0 V, f = 1 MHz
dark current	—	5 nA	—

03 — Alternatives

Closest matches to 4N35

TLP185GB 2.9× higher power dissipation, 2.0× higher dark current, 2.0× higher isolation voltage

MOC3010M 10.0× lower reverse leakage current, 2.0× higher dark current, 2.0× higher output current

PC817 2.9× higher power dissipation, 1.2× higher operating temperature, 1.1× lower forward voltage

TCUT1350X01 5.0× lower dark current, 2.0× lower forward current, 2.0× lower junction capacitance

LTV-354T 20.0× higher dark current, 2.4× higher power dissipation, 2.0× lower breakdown voltage ds

LTV-217-G 1.3× lower isolation voltage, 1.2× higher operating temperature, similar forward current

MOC3063S 3.6× higher power dissipation, 1.3× higher operating temperature, 1.1× lower forward voltage

TLP7820 1.4× higher operating temperature, similar power dissipation, similar isolation voltage

04 — FAQ

Frequently asked questions

What is the breakdown voltage ds?

The breakdown voltage ds is 70 V.

What is the maximum dark current for the 4N35?

The dark current is 5 nA.

What is the forward current of the 4N35?

The forward current is 50 mA.

What is the forward voltage when IF = 10 mA and Tamb = - 55 °C?

The forward voltage is 1.3 V.

What is the isolation voltage of the 4N35?

The isolation voltage is 5 kV VRMS.

What is the junction capacitance of the 4N35?

The junction capacitance is 50 pF at VR = 0 V and f = 1 MHz.

What is the maximum operating temperature of the 4N35?

The operating temperature is 100 °C.

What is the output current of the 4N35?

The output current is 50 mA.