Overview
The LC72121 and the LC72121M and the LC72121V are high input sensitivity (20 mVrms at 130 MHz) PLL frequency synthesizers for 3 V systems. These ICs are serial data (CCB) compatible with the LC72131, and feature the improved input sensitivity and lower spurious radiation (provided by a redesigned ground system) required in high-performance AM/FM tuners.
Functions
â High-speed programmable divider
â FMIN: 10 to 160 MHz ... Pulse swallower technique (With built-in divide-by-2 prescaler)
â AMIN: 2 to 40 MHz ... Pulse swallower technique 0.5 to 10 MHz ... Direct division technique
â IF counter
â IFIN: 0.4 to 15 MHz ... For AM and FM IF counting
â Reference frequency
â One of 12 reference frequencies can be selected (using a 4.5 or 7.2 MHz crystal element) 1, 3, 5, 9, 10, 3.125, 6.25, 12.5, 15, 25, 50, and 100 kHz
â Phase comparator
â Supports dead zone control.
â Built-in unlocked state detection circuit
â Built-in deadlock clear circuit
â An MOS transistor for an active low-pass filter is built in.
â I/O ports
â Output-only ports: 4 pins
â I/O ports: 2 pins
â Supports the output of a clock time base signal.
â Operating ranges
â Supply voltage: 2.7 to 3.6 V
â Operating temperature: â 40 to 85°C
â Package
â DIP22S, MFP24S, SSOP24
â Comparison with the LC72131/M
â Serial data compatible (CCB)
â Identical pin functions
â Two VSS pins were added.
â The DIP version is pin compatible (VSS pins were inserted as the DIP22S NC pins.)
â The MFP product provides a modified pin assignment (The MFP20 package was replaced by an MFP24 package, and extra VSS pins were added.)
â The SSOP24 is a newly developed package that has the same pin assignment as the MFP24S product.
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