MC44BS374T1/374T1A Advance Information

Functional Overview

4 Functional Overview

Figure 2 shows a simplified block diagram of the MC44BS374T1/374T1A device.

The MC44BS374T1/374T1A device has three main sections:

2. A PLL section to synthesize the UHF/VHF output channel frequency (from an integrated

UHF oscillator, divided for VHF output)

3. A modulator section, which accepts audio and video inputs, then uses them to modulate the

UHF/VHF carrier

An on-chip video test pattern generator with an audio test signal is included.

The MC44BS374T1/374T1A operates as a multi-standard modulator and can handle the following systems

using the same external circuit components: B/G, I, D/K, M/N.

High frequency BiCMOS technology allows integration of the UHF tank circuit and certain filtering

functions.

Figure 2. MC44BS374T1/374T1A Simplified Block Diagram

8

13

1

2

6

11

14

9

4

12

7

3

10

15

16

TVOVCC

TVOUT

LOP

VIDEO

SPLLFLT

AUDIO

VCCA

GND

PREEM

XTAL

PLLFLT

GNDD

VCCD

SCL

SDA

BUS SECTION

VCO and PLL SECTION

MODULATOR

SECTION

Clamp

Peak

White

31.25KHz

4MHz

XCO

Ref Divider

/128

Phase

Comp

PLL

Prog

Divider

Prescaler/8

VHF Dividers

Video

Modulator

LPF

LPF

RF Sound

Modulator

ALC

LPF

Prog

Divider

Audio

Amplifier

Sound

Oscillator

and FM

Modulator

Sound

PFD

High Speed

Receiver

UHF OSC

75

Ω

5

GND

Clip

31.25

kHz

FM

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com