Build with 4N35 — Datasheet Specs & AI Design Help

00 — Overview

What the 4N35 does

The 4N35, 4N36, and 4N37 are optocouplers featuring a phototransistor output with a base connection. These devices interface with common logic families while maintaining 5000 V RMS isolation and input-output coupling capacitance below 0.5 pF. They operate with a 6 V reverse voltage limit and 50 mA forward current, delivering a DC current transfer ratio of 100% at 10 mA. Engineers typically use them for AC mains detection, reed relay driving, and switch mode power supply feedback. The parts also support logic ground isolation and high frequency noise rejection within a standard dual-in-line 6 pin package.

Next step

Start building with 4N35 → Every number above is cited straight from the datasheet — ask what they mean for your design, and the assistant answers from the same source documents.

01 — Key specifications

Datasheet parameters

Datasheet parameters for 4N35
Parameter	Min	Typ	Max	Conditions	Source
output current	—	50 mA	—		Vishay datasheet, p. 1 — APPLICATIONS
forward voltage	900 mV	1.3 V	1.7 V	IF = 10 mA, Tamb = - 55 °C; INPUT	Vishay datasheet, p. 2 — APPLICATIONS
operating temperature	-55 °C	—	100 °C		Vishay datasheet, p. 2 — Vishay Semiconductors Optocoupler, Phototransistor Output, with Base C…
power dissipation	—	70 mW	—		Vishay datasheet, p. 1 — APPLICATIONS
forward current	—	50 mA	—		Vishay datasheet, p. 1 — APPLICATIONS
breakdown voltage ds	70 V	—	—	IC = 100 µA, IB = 1 µA; 4N35; collector; OUTPUT	Vishay datasheet, p. 2 — APPLICATIONS
isolation voltage	—	5 kV	—		Vishay datasheet, p. 1 — APPLICATIONS
dark current	—	5 nA	—	VCE = 10 V, IF = 0	Vishay datasheet, p. 2 — APPLICATIONS
output count	—	1	—		Vishay datasheet, p. 1
channel count	—	1	—		Vishay datasheet, p. 1

02 — Alternatives

Closest matches to 4N35

TLP785 2.0× higher dark current, 1.3× higher power dissipation, 1.2× higher operating temperature

LTV-357T 20.0× higher dark current, 3.1× lower output current, 1.3× lower isolation voltage

LTV-354T 20.0× higher dark current, 2.1× higher power dissipation, 1.3× lower isolation voltage

MOC3010M 10.0× lower reverse leakage current, 4.7× higher power dissipation, 2.0× higher dark current

TLP185 20.0× higher forward current, 2.7× higher breakdown voltage ds, 2.1× higher power dissipation

TLP185GB 20.0× higher forward current, 2.7× higher breakdown voltage ds, 2.1× higher power dissipation

AOTE-DCC-AT1019-CUH-L 20.0× higher dark current, 5.0× lower forward current, 1.2× lower output current

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

03 — FAQ

Frequently asked questions

What is the breakdown voltage ds for the 4N35 collector output when IC = 100 µA and IB = 1 µA?

The breakdown voltage ds is 70 V.

What is the channel count of the 4N35?

The channel count is 1.

What is the dark current of the 4N35 when VCE = 10 V and IF = 0?

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 for the INPUT?

The forward voltage is 1.3 V.

What is the isolation voltage of the 4N35?

The isolation voltage is 5 kV.

What is the maximum operating temperature of the 4N35?

The operating temperature is 100 °C.

What is the output count of the 4N35?

The output count is 1.

What is the maximum output current?

The maximum output current is 50 mA.

What is the power dissipation of the 4N35?

The power dissipation is 70 mW.