LM1881, LM1881-X Video Sync Separator is a video sync separator chip produced by Texas Instruments. It has a wide input signal range, strong anti-interference ability and high reliability. It can be widely used in TV, computer, mobile phone and other electronic devices.
The LM1881 family extracts composite, vertical sync, burst/back‑porch, and odd/even field information from NTSC, PAL, and SECAM video signals. It operates from a single 5 V‑12 V supply and requires only a few external components (decoupling capacitor, input coupling capacitor, and a resistor on pin 6 to set internal current levels). The device can handle input amplitudes from 0.5 V to 2 V p‑p and works over an ambient temperature range of –40 °C to +85 °C (LM1881‑X).
Four primary outputs are provided: composite sync, vertical sync, burst/back‑porch, and an odd/even field indicator. These outputs enable applications such as video‑camera lock‑in, frame‑memory field identification, sync recovery, and color‑burst extraction for downstream processing.
| Supply Voltage | 5 V DC to 12 V DC |
|---|---|
| Operating Temperature (LM1881‑X) | –40 °C to +85 °C |
| Power Supply Drain Current | < 10 mA |
| Output Sink Current (Pins 1, 3, 5) | 5 mA |
| Output Sink Current (Pin 7) | 2 mA |
| Vertical Sync Output Pulse Width | 140 ps – 300 ps (typ.) |
The device operates from a single supply voltage between 5 V DC and 12 V DC.
Pin 7 provides an odd/even field indicator that identifies which video field (odd or even) is present at the input, useful for frame‑memory storage and field‑based processing.