Multi-Standard Audio/Video Modulator

The MC44BC374T1 is a Phase-Locked Loop (PLL) tuned, Ultra High Frequency (UHF) and Very High Frequency (VHF), audio/video (A/V), high integration modulator, integrated circuit (IC). It is intended for use in VCRs, Games, and Set-Top box systems. This device uses "T" software.

The MC44BC374T1 is the same hardware package as the MC44BC374T and MC44BC374C. The only difference is the software and the startup channel.

The MC44BC374T1 starts up on Channel '71' (871.25 MHz) and is compatible with the following formats:

• PAL—Phase Alternation Line (European TV format)
• NTSC—National Television System Committee

An on-chip high-speed I²C compatible bus receiver sets the channel. It is tuned by a PLL over the full range of the UHF bands. The modulator incorporates a sound subcarrier oscillator and uses a second PLL to derive 4.5, 5.5, 6.0, and 6.5MHz subcarrier frequencies, which are selectable using the bus.

The modulation standard is chosen using a control bit that selects between System L and System B/G.

The picture-to-sound ratio may be adjusted using the bus. In addition, an on-chip video test pattern generator can be switched ON with a 1KHz audio test signal.

The MC44BC374T1 is available in a 16-pin (SO16NB) package.