MC44BC375U Datasheet, PDF (1/16 Pages) Freescale Semiconductor, Inc – PLL Tuned VHF (Channel 3 / 4)Audio / Video Modulator

Freescale Semiconductor
Data Sheet
Document Number: MC44BC375U
Rev 3, 8/2006
PLL Tuned VHF (Channel 3 / 4)
Audio / Video Modulator
The MC44BC375U and MC44BC375UA are audio/video RF modulators for
use in VCRs, set-top boxes, and similar devices. They are designed for applica-
tions requiring National Television System Committee, NTSC, channel 3 or chan-
nel 4, RF outputs. The difference between the two modulators is the RF output
power level. The nominal RF_OUT level for the MC44BC375U is 76 dBµV (typical)
and the RF_OUT level for the MC44BC375UA is 80 dBµV (typical).
A programmable Phase-Locked Loop (PLL) tunes the modulator, and the de-
sired channel 3 or 4 frequency isselected using the external package pin, Chan-
nel Selection (CHS). No external tank circuit components are required, reducing
the sensitivity of the PCB design and the need for external adjustments. The PLL
obtains its reference from a 4.0 MHz crystal oscillator.
The modulators incorporate a sound subcarrier oscillator and use a second
programmable PLL to derive subcarrier frequencies. The 4.5 MHz or 5.5 MHz
sound carrier frequency is selectable via the package pin, Sound Frequency Se-
lection (SFS). The Picture to Sound subcarrier ratio is also selectable by the pin,
Picture to Sound Selection (PSS), to choose either a 14 dB or 16 dB ratio.
A low-power standby mode is selectable via the pin, Psave/LO, which turns off
all internal VCOs and mixers and simultaneously switches ON an output pin,
Logic Output Port (LOP), which may be used as an antenna switch driver.
MC44BC375U
MC44BC375UA
PLL TUNED VHF
(CHANNEL 3 / 4)
AUDIO / VIDEO MODULATOR
D or EF SUFFIX
SOIC 16 PACKAGE
CASE 751B-05
Features
• Two RF output power levels offered:
• MC44BC375U has typical RF_OUT power of 76 dBµV
• MC44BC375UA has typical RF_OUT power of 80 dBµV
• U.S. broadcast frequency for Channel 3 or 4 operation is selected by CHS pin
• Programmable VHF oscillator and sound subcarrier oscillator. No external varicaps,
diodes/inductors, or tuned components required.
• Programmable Picture/Sound Carrier Ratio (14 dB or 16 dB) is selected by PSS pin
• Programmable Sound Subcarrier Oscillator (4.5 or 5.5 MHz) is selected by SFS pin)
• Peak White Clip
• Low-power standby mode is selected by the Psave/LO pin
• Logic Output Port is selected by Psave/LO pin (Antenna Switch Driver)
• Transient output inhibit during PLL Lock-up at power-ON
• Available in Pb-free, RoHS compliant, narrow body SOIC 16 package
• Also available, for a limited time, in the standard Pb package with the D suffix
Video In
Crystal
Audio In
MC44BC375U/UA
Clamp
Clip
VCO
Mixer
Σ
AM/FM
Audio
Control
Mixer
Channel 3/4
TVOUT
ORDERING INFORMATION
Device
Temp. Range
MC44BC375UEF, R2 ^{-20°C to +85°C}
MC44BC375UAEF, R2 ^{-20°C to +85°C}
MC44BC375UD, R2 -20°C to +85°C
MC44BC375UAD, R2 ^{-20°C to +85°C}
Note: For tape and reel, add the R2 suffix.
RoHS
Yes
Yes
No
No
© Freescale Semiconductor, Inc., 2006. All rights reserved.