Document
Freescale Semiconductor
Document Number: MC44CC375AV Rev 1, 11/2008
PLL Tuned VHF (Channel 3 / 4) Audio / Video Modulator
MC44CC375AV
The MC44CC375 CMOS RF modulator is the latest generation of the legacy MC44BC375 products. www.datasheet4u.com The MC44CC375AV is an audio/video RF modulator for use in VCRs, set-top PLL TUNED VHF boxes, and similar devices. It is designed for applications requiring US broad(CHANNEL 3/4) cast, channel 3 or channel 4, RF outputs. AUDIO/VIDEO MODULATOR A programmable Phase-Locked Loop (PLL) tunes the modulator, and the desired channel 3 or 4 frequency is selected using the external package pin, Channel 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 sound oscillator can be turned ON and OFF by the external package pin Sound Oscillator Control (SOC). A fixed Picture to Sound ratio of 12 dB and 4.5 MHz sound subcarrier are used for MC44CC375AV. A low-power standby mode is selectable via the pin, Power Save (PSAVE), which turns off all internal VCOs and mixers. Also included in this new generation CMOS RF modulator is the Sound AuxilEF SUFFIX iary Input, pin AUX, which bypasses the sound FM modulator. This direct sound SOIC 16 PACKAGE RF modulator has found more and more applications in BTSC stereo systems. CASE 751B-05 • U.S. broadcast frequency for Channel 3 or 4 operation is selected by CHS pin • Sound Oscillator ON/OFF control selectable by pin SOC • Picture to Sound ratio set to 12 dB • Sound subcarrier frequency set to 4.5 MHz • Low-power standby mode selectable by pin PSAVE • Direct RF sound carrier input pin AUX (FM modulator bypassed for stereo sound applications) • ESD protection up to 2 kV • Peak White Clip enabled • Transient output inhibit during PLL Lock-up at power-ON • Available in Pb-free, RoHS compliant, narrow body SOIC 16 package. ORDERING INFORMATION
Device MC44CC375AVEF, R2 Note: For tape and reel, add the R2 suffix. Temp. Range 0°C to +70°C RoHS Yes
MC44CC375AV Video In
Clamp Clip VCO Mixer
Crystal
FM Audio Control
Σ
Mixer
TVOUT
Audio In
AUX
Channel 3/4
This document contains certain information on a new product. Specifications and information herein are subject to change without notice.
© Freescale Semiconductor, Inc., 2008. All rights reserved.
PIN DESCRIPTIONS
SO16 Pin Package
CHS GND
www.datasheet4u.com
1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
PSAVE AUX PLLFLT No Connect VCC RFOUT GND VCC
SOC XTAL PREEM AUDIO SPLFLT VIDEO
Figure 1. Pin Connections Table 1. Package Pin Description
Pin Number 1 2 3* 4 5 6 7 8 9 10 11 12 13 14 15 16 Pin Name CHS GND SOC XTAL PREEM AUDIO SPLFLT VIDEO VCC GND RFOUT VCC No Connect PLLFLT AUX PSAVE Description Channel Select, Low - CH3; High - CH4 Ground Sound Oscillator ON/OFF Control, Low - ON, Open - OFF Crystal Input Pre Emphasis Audio Input Sound PLL Loop Filter Video Input VCC Audio Ground TV Output Plus VCC Do not connect PLL Loop Filter Auxiliary Input Power Save Mode Control, Low - Power Save; High - Normal
* Pin 3, SOC, should not be pulled up to high voltage. It has an internal pull-up of 1.8V.
MC44CC375AV 2 Digital Home Freescale Semiconductor
FUNCTIONAL OVERVIEW
Figure 2 shows a simplified block diagram of the MC44CC375AV device. There are two main sections: 1. A PLL section to synthesize the VHF output channel frequency for channel 3 or channel 4. 2. A modulator section which accepts audio and video inputs and modulates the VHF carrier. The high frequency CMOS technology allows integration of the UHF tank circuit and certain filtering functions eliminating the need for a number of external components.
www.datasheet4u.com
VIDEO
8 Peak White Video Modulator
Internal Control Bus
SPLFLT
7
Clamp 31.25 kHz Sound PFD Program Divider
VCC
12
MODULATOR SECTION
Sound Oscillator and FM Modulator LPF ALC 10 GND 6 Audio Amplifier 5
AUDIO PREEM VCC
RFOUT 11
9
FM RF Sound Modulator
15 AUX VHF Dividers
SOC
3 Control Section Prescaler ÷8
VCO and PLL SECTION
UHF OSC (2 x Fo)
Ref Divider Phase ÷128 Comp. 31.25 kHz
PSAVE 16 CHS
1
÷2
Program Divider ÷N11:N0
XO Prescaler
13
NO CONNECT
XCO
2
14
4
GND
PLLFLT
XTAL (4 MHz)
Figure 2. MC44CC375AV Simplified Block Diagram POWER SUPPLY Do NOT bias any other pin before VCC is applied to the device. STANDBY MODES During standby mode, the modulator is switched to low power consumption. The sound oscillator, UHF oscillator and VHF dividers, video and sound modulator sections bias are internally turned OFF. The modulator is programmed in standby mode when pin 16, PSAVE, is set to a “LO” level TRANSIENT OUTPUT INHIBIT To minimize the risk of interference to other channels while the UHF PLL is acquiring a lock on the desired frequency, the Sound and Video modulators are turned OFF at power-ON (i.e., VCC is switched from 0 V to 3.3 V). There is a time-out of 263 ms until the output is enab.