Document Number: MC44BC375U
Rev 3, 8/2006
Freescale Semiconductor
Data Sheet
© Freescale Semiconductor, Inc., 2006. All rights reserved.
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.
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
MC44BC375U
MC44BC375UA
PLL TUNED VHF
(CHANNEL 3 / 4)
AUDIO / VIDEO MODULATOR
D or EF SUFFIX
SOIC 16 PACKAGE
CASE 751B-05
Crystal
Mixer
Mixer
Clamp
Clip
VCO
AM/FM
Audio
Σ
Control
MC44BC375U/UA
Video In
Audio In
TVOUT
Channel 3/4
ORDERING INFORMATION
Device Temp. Range RoHS
MC44BC375UEF, R2
-20°C to +85°C
Yes
MC44BC375UAEF, R2
-20°C to +85°C
Yes
MC44BC375UD, R2
-20°C to +85°C
No
MC44BC375UAD, R2
-20°C to +85°C
No
Note: For tape and reel, add the R2 suffix.
页面指南
