MC44BC374B数据手册恩XP中文资料规格书

描述 Description

Overview The MC44BC374B is a Phase-Locked Loop (PLL) tuned Ultra High Frequency (UHF) and Very High Fre-quency (VHF) audio/ video (A/V) modulator integrated circuit (IC). It contains an antenna booster/ splitter for VCR, Games, and Set-Top box systems. The MC44BC374B has dual television outputs. The MC44BC374B 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 is used to set 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 can be 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 gener-ator can be switched ON with a 1KHz audio test signal. The dual output modulated signal is added to both antenna booster/ splitter outputs. The MC44BC374B is available in two different size 24-pin packages:SO24-WB (wide body) TSSOP24

特性 Features

•No external varicaps diodes/ inductor or tuned components
•Channel 21-69 UHF operation
•VHF range possible by internal dividers (30MHz–450MHz)
•Integrated on-chip programmable UHF oscillator
•Extremely low external components count
•High speed read and write I2C-bus compatible (800kHz)
•Fixed video modulation depth (80% in PAL and 90% in SECAM)
•Peak White Clip disabled
•Programmable picture/sound carrier ratio (12dB and 16dB)
•Integrated on-chip programmable sound subcarrier oscillator (4.5MHz to 6.5MHz)—No external vari-caps
•On-chip video test pattern generator with sound test signal (1kHz)
•Low-power programmable modulator standby mode (booster active)
•Transient output inhibit during PLL Lock-up at power-ON
•Logical Output Port controlled by bus
•Integrated Antenna Booster/ Splitter (40Mhz to 860Mhz)
•Custom masked versions with unique start-up settings possible (no I2C bus programming required)
•Extremely robust ESD protection, minimum 4kV, typical 6kV