LC5121 PLL Frequency Synthesizer

Overview

This 27 MHz band, PLL frequency synthesizer LSI chip is designed specifically for CB transceivers. The LC7185-8750 incorporates PLL circuitry and a controller for CB applications on a single CMOS chip. The controller handles the PLL circuitry, frequency data ROM, channel preset/recall RAM, and LED display driver. It also supports channel preset/recall, and emergency channel call.
This PLL-circuit use a ROM programmable divide-by-N counter. The ROM-table is programmed from factory.

Pin	Name	Description
1	SA	Display Segment A
2	SB	Display Segment B
3	SC	Display Segment C
4	SD	Display Segment D
5	SE	Display Segment E
6	SF	Display Segment F
7	SG	Display Segment G
8	Vss	Ground
9	XO	X-tal Output
10	XI	X-tal Input
11	GND	Ground
12	F in	VCO Frequency Input
13	Vcc	Positive Voltage Supply
14	AO	Loop filter Amplifier Output
15	AI	Loop filter Amplifier Input
16	DO	Phase Detector Output
17	LD	Loop Detected
18	T/R	Transmit / Receive
19	EMG	Channel 9
20	U/D	Program UP / Program DOWN
21	RFST
22	DI	Display Segment Select output

Explanation of pin function terms

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