The LC72131 and LC72131M are PLL frequencysynthesizers for use in tuners in radio.
- • High speed programmable dividers
— FMIN: 10 to 160 MHz ……….pulse swallower
(built-in divide-by-two prescaler)
— AMIN: 2 to 40 MHz …………..pulse swallower
0.5 to 10 MHz ………..direct division
• IF counter
— IFIN: 0.4 to 12 MHz ………..AM/FM IF counter
• Reference frequencies
— Twelve selectable frequencies
(4.5 or 7.2 MHz crystal)
1, 3, 5, 9, 10, 3.125, 6.25, 12.5, 15, 25, 50 and 100 kHz
• Phase comparator
— Dead zone control
— Unlock detection circuit
— Deadlock clear circuit
• Built-in MOS transistor for forming an active low-pass
filter
• I/O ports
— Dedicated output ports: 4
— Input or output ports: 2
— Support clock time base output
• Serial data I/O
— Support CCB format communication with the
system controller.
• Operating ranges
— Supply voltage……………………4.5 to 5.5 V
— Operating temperature…………–40 to +85°C
• Packages
— DIP22S/MFP20
I found such a chip in an old music center.The chip comes with 20 and 22 pins
Here is the connection of this chip in the music center
