The MC44BS373CA audio and video modulator is for use in VCRs, set-top boxes, and similar devices.

• Supports multiple standards
• TV output level 82 dBµV typical
• 5- and 3.3-V compatible I2 C bus

The MC44BS373CA is a multi-standard, PAL/SECAM/NTSC modulator. The channel is set by an on-chip high-speed I2C-compatible bus receiver. A phase-locked loop (PLL) tunes the modulator over the full UHF range. The modulator incorporates a sound subcarrier oscillator and uses a second PLL to derive 4.5-, 5.5-, 6.0-, and 6.5-MHz subcarrier frequencies. These frequencies are selectable by bus. The modulation standard can be chosen using a control bit that selects between positive and negative

modulation. 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 1-kHz audio test signal.

The MC44BS373CA also has the following features:

• Integrated on-chip programmable UHF oscillator
• No external varicaps diodes/inductor or tuned components
• Extremely low external component count
• Channel 21–69 UHF operation
• VHF range possible by internal dividers (30–450 MHz)
• Boosted TVOUT level (82 dBµV typical)
• High-speed read and write I2C bus compatible (800 kHz)
• I2C address selectable by pin (four choices) using external resistor (available only in QFN20 package)
• I2C bus 5- and 3.3-V compatible
• Fixed video modulation depth (93% typical in system L and 82% typical in the other standards)
• Peak white clip disabled by bus
• Programmable picture/sound carrier ratio (12 and 16 dB)
• Integrated on-chip programmable sound subcarrier oscillator (4.5, 5.5, 6.0 and 6.5 MHz)—no
• external varicaps
• Programmable sound reference frequency (31.25 and 62.5 kHz)
• Direct RF sound modulator input (FM and AM modulator bypassed) for NICAM or stereo sound applications (available only in QFN20 package)
• On-chip video test pattern generator with sound test signal (1 kHz)
• Low-power programmable modulator standby mode
• Transient output inhibit during PLL lock-up at power-on
• Logical output port controlled by bus
• ESD protection, minimum 4 KV