Overview

The LC72341G/W, LC72342G/W, and LC72343G/W are single-chip microcontrollers with both a 1/4-duty 1/2-bias LCD driver circuit and a PLL circuit that can operate at up to 250 MHz integrated on the same chip. These ICs are ideal for use in portable audio equipment.

Functions

• High-speed programmable divider

• Program memory (ROM)

— LC72341G/W: 2048 words × 16 bits (4KB)

— LC72342G/W: 3072 words × 16 bits (6KB)

— LC72343G/W: 4096 words × 16 bits (8KB)

• Data memory (RAM)

— LC72341G/W: 128 words × 4 bits

— LC72342G/W: 192 words × 4 bits

— LC72343G/W: 256 words × 4 bits

• Instruction cycle time

— 40 µs (for all single-word instructions.)

• Stack

— 4 levels (LC72341G/W)

— 8 levels (LC72342G/W, and LC72343G/W)

• LCD driver

— 48 to 80 segments (1/4-duty 1/2-bias drive)

• Timer interrupts

— One timer circuit providing intervals of 1, 5, 10, and 50 ms.

• External interrupts

— One external interrupt (INT)

• A/D converter

— Two channels (5-bit successive approximation)

• Input ports

— 7 (Of which two can be switched to function as A/D converter inputs)

• Output ports

— 6 (Of which one can be switched to function as the BEEP tone output. Two ports are open-drain ports.)

• I/O ports

— 16 (Of which 8 can be selected to function as LCD ports as mask options.)

• PLL circuit

— Two types of dead band control are supported, and an unlock detection circuit is included.

Reference frequencies of 1, 3, 5, 6.25, 12.5, and 25 kHz can be provided.

• Input frequency range

— FM band: 10 to 130 MHz 130 to 250 MHz

— AM band: 0.5 to 15 MHz