MC44BS374CA中文资料PLL Tuned UHF and VHF Audio/Video High Integration Modulator数据手册恩XP规格书

描述 Description

Overview The MC44BS374CA is a multi-standard, PAL/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.

特性 Features

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