MC44BC374T1 データシートの表示（PDF） - Motorola => Freescale

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MC44BC374T1

PLL Tuned UHF and VHF Audio/Video High Integration Modulator

Motorola => Freescale 

Features

1 Features

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 6.5MHz subcarrier frequencies. These frequencies are

selectable using the bus.

The modulation standard is set to System B/G.

The picture-to-sound ratio is adjusted using the bus. In addition, an on-chip video test pattern generator can

be turned ON with a 1KHz audio test signal.

Compared with the MC44BC374C, this modulator has one IIC programming difference, a hardware

standby mode in addition to the software standby mode, and no logic output port.

Compared with the MC44BC374T, this modulator has a different start-up channel.

The MC44BC374T1 also has the following 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 I2C-bus compatible (800kHz)

• Fixed video modulation depth (80%)

• Peak White Clip disabled via the bus

• Programmable picture/sound carrier ratio (12dB and 16dB)

• Integrated on-chip programmable sound subcarrier oscillator

(4.5MHz to 6.5MHz)—No external varicaps

• On-chip video test pattern generator with sound test signal (1kHz)

• Low-power modulator standby mode programmable by I2C bus or

switchable by STBY pin voltage

• Transient output inhibit during PLL Lock-up at power-ON

• Start-up on channel ‘71’ (871.25 MHz)

• Extremely robust ESD protection, minimum 4kV, typical 6kV

2

MC44BC374T1 Technical Data

MOTOROLA

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