Single for Video SCART interface

Summary: in many SCART application, due to the complex signal switching requirements, usually through a dedicated IC for SCART connection.

This single application will bring cost SCART on pressure.

This article describes the circuit is an optional programme to deliver high quality SCART interface without the need for additional switches or multiplexer.

In Europe, external and televisions, set-top box, video recorder (VCR) and other video peripherals connect through SCART Peritel connector completed, EN50049 on its PIN length definition.

According to the specific purpose of SCART connector (SCART, AUX SCART TV or VCR SCART), the connector can be used as input, output, or at the same time as the input/output.

In addition, the request will be RED and S-VHS Cvbs pin (15 foot and 20 feet) and chroma (C) and the brightness (Y) signal pin multiplexing, making the interface more complex.

The vast majority of cases, taking into account the complexity of signal switching, usually requires the use of dedicated SCART interface IC, but for a small, one-way applications resulted in a significant cost pressures.

The simplest structure is based on the TV input and encoder output SCART Switch of sin.

The following circuits provide an alternative, to achieve high quality SCART connection and requires no additional switches or multiplexer.

Illustration, a four-channel video MAX4384 operational amplifier for R/chroma and Cvbs/brightness format of multiplexing and buffering.

MAX4451 dual channel video amplifier on the BLUE and GREEN signals provide buffering. Figure 1 shows the output SCART to SCART input in Figure 2, Figure 3 is bi-directional SCART.

　　

　　

Figure 1. Use MAX4384 and MAX4451 SCART output

　　

　　

Figure 2. Use MAX4384 and enter SCART MAX4451 constitute

　　

　　

Figure 3. Dual SCART

MAX4384 and circuit design to MAX4451 is to transmit the configuration to gain 2-phase amplifier, using equivalent input and feedback resistor.

Resistance values can not be too large to avoid band pole; nor too small, so as not to affect the linear drive. For input or output SCART, chroma/luma enabling signal after connecting to the RP rear Red/Cvbs in enable, control through a single PIN, discrete resistors (Rdrive and Rterm) as a driver and termination. Figure 3 shows a two-way SCART, enabling output SCART and enter it into the ground, making RD/T after operational amplifier output to ground, thereby using output SCART drive resistor (Rdrive) as input SCART of the termination (Rterm). Typically, driven by the DAC output SCART, close the DAC to pull all input to ground potential.

Due to the dedicated number enter SCART Switch does not contain a Cvbs and Y/C/Red multiplexer, input or output SCART in MAX4384 can complement these switch expansion.

The audio portion of the SCART interface can adopt MAX4493-MAX4495 series audio amplifier that can constitute a stereo schema or left and right channel audio mixing schemas.