Low power analogue video decoder for automotive camera systems

October 25, 2013 // By Graham Prophet
The TW9990 NTSC/PAL/SECAM decoder featuring differential inputs reduces the bill of materials and enhances performance in in-car systems

Intersil's TW9990 is a highly integrated analogue video decoder that eliminates the need for external op amps while enabling performance advantages through programmable short-to-battery and short-to-ground detection. The TW9990 video decoder is suitable for automotive rear camera displays and other camera systems.

The low power analogue video decoder supports NTSC/PAL/SECAM single-ended, differential, and pseudo differential composite video inputs as well as S-Video. A single 27 MHz crystal is all that is needed to decode all analogue video standards. Typical power consumption is approximately 100 mW for composite inputs. A power-down mode further reduces consumption.

Most automotive analogue cameras are cabled as differential twisted pair to reduce common mode noise. Traditional analogue video decoders only support single-ended inputs, meaning automotive system designers must place a video op amp in front of the decoder to convert differential signals to single-ended. The TW9990 video decoder eliminates the need for the external op amp and the associated cost, as it supports differential composite video signals directly, and has built-in programmable short-to-battery and short-to-ground detection.

It features;

- NTSC/PAL/SECAM 4H adaptive comb filter Y/C separation

- Two 10-bit ADCs and analogue clamping circuit

- Fully programmable static gain or automatic gain control for the Y channel

- Built-in analogue anti-alias filter

- Image enhancement with peaking and CTI

- Advanced synchronisation processing and sync detection for handling non-standard and weak signals

- Short-to-Battery and Short-to-Ground Detection

- Available in a wettable flank QFN package, which enables visual solder inspection.

- AEC-Q100 Grade 2 Qualified

In a 32-lead 5 x 5mm WFQFN it costs $2.60 (1000).

Intersil; www.intersil.com/products/TW9990