6N137SD

The 6N137SD is a high-speed optocoupler with TTL-compatible output and an enable input, in a surface-mount (SD) package. It provides galvanic isolation between input and output (commonly used up to several kilovolts RMS), making it ideal for linking microcontroller or digital logic to high-voltage or noisy circuitry.
Key points
- Input side: infrared LED; output side: photodetector plus a TTL buffer.
- Output: TTL-compatible, open-collector style; requires a pull-up resistor to a suitable logic supply.
- Enable input: an enable pin allows gating the output (disable/tri-state when asserted, depending on configuration).
- Package: 8-pin package, with SD variant for surface-mount.
Typical uses
- Isolated digital interfaces between microcontrollers and higher-voltage / noisy systems.
- Data communication links requiring fast, buffer-friendly isolation.
- Any design needing a simple, fast, isolated logic signal with optional output enable.
Note: Check the exact pinout and operating ranges in the specific datasheet for the SD variant you’re using, as packaging and pin assignments can differ slightly.

6N137SD is a high‑speed optocoupler with TTL‑compatible logic output. Key features:
- High-speed optocoupler with TTL/CMOS compatible output gate
- Output is open-collector; requires pull-up resistor to Vcc
- Isolation rating: typically 5 kV RMS (input/output)
- Data rate: up to about 10 Mbps
- Fast propagation: typical tPHL/tPLH in the tens of ns (e.g., ~45 ns)
- CTR range: wide and IF‑dependent (typical 50%–600% depending on IF)
- Input LED: forward current roughly 1 mA–2 mA (recommended) for logic operation
- Output supply: Vcc ≈ 4.5–5.5 V (TTL level)
- Package: 8‑pin DIP or SOIC (SD variants)
- Applications: fast digital isolation in microcontroller, logic interfaces, and data buses
Note: exact numbers vary by manufacturer revision (SD suffix), so consult the specific datasheet for your batch.

8-pin DIP (dual-inline package), through-hole.

- Pin count: 8 pins (DIP-8/SO-8).
- Function: High‑speed optocoupler with TTL‑compatible (open‑collector) output and an enable input. The input is an LED; the output side provides isolated TTL logic and requires a pull‑up resistor. The enable input can disable the output.

Manufacturer: NEC Electronics (now Renesas Electronics Corporation).
What kind of company: A Japanese multinational semiconductor and electronics company that designs and manufactures semiconductors and related components.

6N137SD is a high-speed, TTL-compatible optocoupler with an open-collector output. Applications: galvanic isolation of fast digital signals between voltage domains (MCUs, DSPs, FPGAs); isolation of data interfaces (SPI, I2C, parallel buses); protection against noise and ground loops in industrial automation, medical and telecom equipment, and computer gear; isolated feedback/drive interfaces in switch‑mode power supplies.

6N137SD is a high-speed, TTL‑compatible optocoupler (open‑collector). Direct equivalents/cross‑refs include:
- 4N137 (same family, DIP‑8, TTL output)
- HCPL‑0630 / HCPL‑0631 (Broadcom/Avago high‑speed optocouplers with TTL‑like outputs)
Note: pinouts and electrical specs (speed, CTR, isolation) vary by part; always verify datasheets before substituting.