A high-speed optocoupler for isolating digital signals, in DIP-8. An input LED (anode/cathode) drives an internal photodiode and a logic-gate output stage, giving a clean open-collector logic output that keeps up to 10 Mbit/s, far faster than a phototransistor optocoupler like the PC817. An output enable pin (VE) gates the output and lets several share a bus. It is the standard way to cross an isolation barrier for a UART, SPI clock, encoder signal, or gate-drive command while blocking high voltage and breaking ground loops. Needs a pull-up on the open-collector output. Pin 4 is not connected.

Pinout

Pin	Name	Type	Function
1	NC	unconnected	No internal connection. Leave floating or tie to ground per PCB layout preference.
2	ANODE	input	Anode of the input AlGaAs LED. Typical forward current IF = 5 mA (max 15 mA), VF ~1.4-1.75 V. Drive with a current-limiting resistor from the logic source.
3	CATHODE	input	Cathode of the input AlGaAs LED. Return path for the LED forward current; typically driven low by the source logic gate through a series resistor.
5	GND	power_in	Output-side ground reference. Must be well-decoupled to VCC (pin 8) with a 0.1 uF ceramic capacitor placed close to the device.
6	VO	output	Open-collector Schottky-clamped output. Requires an external pull-up resistor (typ. 350 Ω to VCC). Sinks up to 13 mA in the low state; propagation delay ~48 ns (10 MBd data rate).
7	VE	input	Enable input. When held high (or left open with internal pull-up considerations), the output responds to LED current. When pulled low, the output is disabled (held high). Tie to VCC if not used.
8	VCC	power_in	Output-side supply voltage, 4.5 V to 5.5 V (absolute max 7 V). Bypass to GND (pin 5) with a 0.1 uF ceramic capacitor placed close to the device.

Key specifications

Parameter	Value
Type	High-speed logic optocoupler
Data rate	10 Mbit/s
Input	LED (anode/cathode)
Output	open-collector logic (needs pull-up)
Enable	VE output-enable pin
Isolation	~3750 Vrms
CTR/coupling	logic-level (not linear)
Package	PDIP-8 (pin 4 = NC)

Ordering variants

6N137 (PDIP-8)
6N137S (SOIC-8, gull-wing)

CAD (KiCad official)

Symbol: Isolator:6N137
Footprint: Package_DIP:DIP-8_W7.62mm
3D model: DIP-8 (KiCad packages3D)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: onsemi datasheet (12 pp, sha256 4926d748b1db9af4, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF