VT4T5UF2021

The VT4T5UF2021 is a combination tuner, demodulator and modulator in one package. This unit is compatible with North American NTSC television broadcast
signals. An internal Phase-Locked Loop circuit performs all of the required tuning functions. Digital control information is provided to the unit on I2C serial data bus. The tuner and demodulator blocks are internally connected, providing an IF sample point for test purposes. The modulator has separate video and audio inputs and control connections. This single package configuration is useful when there is no need to manipulate the AGC or IF signals prior to demodulation, and provides for a simplified system design. The RF connectors are mounted on the end of the housing so thatthe smallest possible area is used on the rear panel of the end product.

The VT4T5UF2021 feature is electrically controlled via an external interface pin. Output channel 3 or 4 is also electrically selected by asserting 5 V or ground on an external pin. The internal tuner sample point is always active, allowing the tuner and demodulator functions to be used at all times, regardless of the condition of the RF pass-through and the modulator output. Demodulated audio, video AGC and AFT outputs are also provided. The AGC control line from the demodulator to the tuner is not accessible to the system designer.