GENERAL DESCRIPTION

The PCF1178C is a single chip, 4.19 MHz CMOS car clock circuit providing hours, minutes and seconds functions. It is designed to drive a 4-digit duplex liquid crystal display (LCD).

Two external single-pole, single-throw switches will accomplish all time setting functions. Time calibration and voltage regulator are electrically programmable via an on-chip EEPROM. The circuit is battery-operated via an internal voltage regulator and an external resistor.

FEATURES

• Internal voltage regulator is electrically programmable for various LCD voltages

• Time calibration is electrically programmable (no trimming capacitor required)

• LCD voltage adjusts with temperature for good contrast

• 4.19 MHz oscillator

• 12-hour or 24-hour mode

• Operating ambient temperature: −40 to +85 °C

• 28-lead plastic SMD (SO28)

• 1 Hz set mode.