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). The circuit is battery-operated via an internal voltage regulator and an external resistor.
The PCF1178C is a single-chip, 4.19 MHz CMOS car clock circuit designed to drive a 4-digit duplex liquid crystal display (LCD). It features an internal voltage regulator that is electrically programmable for various LCD voltages and includes time calibration that is also electrically programmable, eliminating the need for trimming capacitors. The circuit operates in either 12-hour or 24-hour modes and is battery-operated via an internal voltage regulator and an external resistor.
The device utilizes two external single-pole, single-throw switches to accomplish all time-setting functions, including hours and minutes adjustment. It incorporates a debounce circuit to protect against contact bounce and parasitic voltages. The chip is available in a 28-lead plastic SMD (SO28) package or as an uncased chip.
| Oscillator Frequency | 4.19 MHz |
|---|---|
| Operating Ambient Temperature | -40 to +85 °C |
| Package Type | 28-lead plastic SMD (SO28) |
| Supply Voltage Range | 3 to 6 V |
| Supply Current | 700 µA (Typ) |
| External Capacitance | 47 µF |
| Oscillator Start Time | 200 ms |
The device includes a 4.19 MHz oscillator.
The internal voltage regulator is electrically programmable for various LCD voltages via the VPP pin.
No, time calibration is electrically programmable, so no trimming capacitor is required.
It is available in a 28-lead plastic SMD (SO28) package.