Video-Signal Conditioners with AGC and Back-Porch Clamp

The MAX7450/MAX7451/MAX7452 complete front-end video-signal conditioners are designed to improve the quality of standard-definition video signals. The devices restore the DC level of the video input, correct for amplitude errors up to ±6dB, detect fault conditions, and filter out-of-band noise. The MAX7450/MAX7451/MAX7452 optimize the signal quality for further video processing through a crosspoint switch or video decoder (ADC). Each device integrates an input video clamp, automatic gain control (AGC), loss-of-sync (LOS) detector, and an out-of-band noise/lowpass filter. These devices also incorporate a user-selectable buffer gain (0 or +6dB) and an AGC-disable function.

The MAX7450 and MAX7451 operate from dual power supplies of ±5V or ±3.3V respectively, and they restore the video blanking level to GND. The MAX7452 operates from a single +5V supply and features a user-adjustable clamp level.

The devices are available in an 8-pin SO package with an exposed pad and are specified for operation over the extended (-40°C to +85°C) temperature range.

Applications

* Security Video Systems * Signal Conditioner for Standard-Definition * Video Inputs * Video Routing and Switching Systems

* Back-Porch Clamp to GND (MAX7450/MAX7451)

* Adjustable Back-Porch Clamp (MAX7452)

* Automatic Gain Control (±6dB Range) Normalizes Signals to Standard Video Level

* Input Fault Detection with LOS Output

* Inherent 50Hz/60Hz Input Rejection of 60dB

* Single-Supply Operation: MAX7452 (+5V)

* Out-of-Band Noise Filter

* Output Buffer Drives Standard 150Ω Video Load with 0dB or +6dB Gain

* Dual-Supply Operation

* MAX7450 (±5V)

* MAX7451 (±3.3V)

* Tiny 8-Pin SO Package