MC145149 Datasheet (Motorola) - Dual PLL Frequency Synthesizer

MC145149, Dual PLL Frequency Synthesizer

INPUT PINS OSCin, OSCout Reference Oscillator Input/Output (Pins 15, 16) These pins form a reference oscillator when connected to terminals of an external parallel *resonant crystal.

Frequency *setting capacitors of appropriate value must be connected from OSCin and OSCout to ground.

MOTOROLA SEMICONDUCTOR TECHNICAL DATA Order this document by MC145149/D MC145149 Dual PLL Frequency Synthesizer Interfaces with Dual Modulus Prescalers The MC145149 contains two PLL Frequency Synthesizers which share a common serial data port and common reference oscillator.

The device contains two 14 stage R counters, two 10 stage N counters, and two 7 stage A counters.

All six counters are fully programmable through a serial port.

The divide ratios are latche

MC145149 Features

* ternal reference, OSCout should be left open. fin1, fin2 Frequency Inputs (Pins 4, 7) Input frequency from an external VCO output. Each rising

* edge signal on fin1 decrements the N counter, and when appropriate, the A counter of PLL 1. Similarly, fin2 decrements the counters of PLL 2. These