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onsemi 4N35SM — Optoisolators

4N35SM onsemi Optoisolator – 4170Vrms, 100% CTR

MPN4N35SM
Active

onsemi 4N35SM, single-channel DC-input transistor-output optoisolator, 4170Vrms isolation, 100% min CTR at 10mA, 6-SMD Gull Wing, -40°C to 100°C, tube packaging.

$0.7400Ref. price · indicative, final on quote
onsemi 4N35SM datasheet (PDF)
Packaging6-SMD, Gull Wing
RoHSROHS3 Compliant
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Aug 2026

Specifications

4N35SM specifications
ParameterValue
Input typeDC
Output typeTransistor with Base
MountingSurface Mount
Voltage - isolation4170Vrms
Voltage - output30V
Voltage - forward (Vf)1.18V
Current transfer ratio100% @ 10mA
Current - DC forward (If)60 mA
Operating temperature-40°C ~ 100°C
PackageTube
Case6-SMD, Gull Wing
Channels1
Vce saturation300mV
Turn on (Turn off time)2µs, 2µs

Product details

4170Vrms isolation with transistor base access

The 4N35SM is a single-channel optoisolator from onsemi that provides 4170Vrms of galvanic isolation between a DC input LED and a phototransistor output with a separate base terminal. The base access lets you tailor the switching threshold or add negative bias to improve noise margin in industrial environments.

100% CTR floor and 2µs switching

Typical turn-on and turn-off times of 2µs each support 250kHz-class switching, adequate for PLC digital inputs, isolated serial links, and motor-drive fault feedback.

Active production, SMD Gull Wing package

The 6-SMD Gull Wing package is pick-and-place ready and shares the same 6-pin footprint as the through-hole 4N35VM, easing board migration from DIP to SMT.

Industrial temperature range and collector rating

Maximum collector-emitter voltage is 30V, and the output transistor saturates at 300mV max — enough headroom for 24V logic rails and 5V/3.3V microcontroller inputs with a pull-up resistor.

Frequently asked questions

What is the difference between 4N35SM and the standard through-hole 4N35?

The 4N35SM uses a 6-SMD Gull Wing surface-mount package, while the standard 4N35 (e.g., 4N35VM) is a 6-pin DIP through-hole package. All other key ratings — 4170Vrms isolation, 100% min CTR, 2µs switching, -40°C to 100°C range — are identical between the two variants.

Can 4N35SM replace 4N28SM in an existing design?

The 4N35SM offers a lower Vce saturation of 300mV max versus 500mV max for the 4N28SM, which improves output voltage swing at low collector currents. Both share the same 4170Vrms isolation, 2µs switching, and 6-SMD Gull Wing package, so a drop-in replacement is possible if the CTR and saturation specs meet your circuit margin.