PCF1178C is a single chip, 4.19 MHz CMOS car clock circuit providing hours, minutes and seconds functions.
The PCF1178C is a single chip, 4.19 MHz CMOS circuit providing hours, minutes, and seconds functions designed to drive a 4-digit duplex LCD display without requiring trimming capacitors. It features an internal voltage regulator that is electrically programmable for various LCD voltages and includes time calibration via an on-chip EEPROM.
The device operates in either 12-hour or 24-hour modes, selectable by connecting the MODE pin to Vpp or Vss respectively. Time setting functions are accomplished using two external single-pole, single-throw switches (S1 and S2) which control hour and minute adjustments. The circuit is battery-operated via an internal voltage regulator and an external resistor.
| Operating Ambient Temperature | -40 to +85 °C |
|---|---|
| Package Type | 28-lead plastic SMD (S028) |
| Display Type | 4-digit duplex LCD |
The adjustable voltage regulator controls the supply voltage in relation to temperature for good contrast, with programming done via the DATA input and SEL pin.
The device operates within an ambient temperature range of -40 to +85 °C.
When the temperature reaches +85 °C, the voltage drops from 4.5 V to 4 V.
Connecting the TS pin to Vss stops all counters for seconds, minutes, and hours.