W85C178 Datasheet PDF – Real Time Clock IC

Part Number : W85C178

Function : Real Time Clock With 128-Byte RAM

Package : DIP 24P

Manufacturers : Winbond


W85C178 Real Time Clock

Description :

The Real Time Clock with 128-byte RAM is a peripheral device for use with various microprocessors. The W85C178 is designed to be a direct replacement for the MC146818A. The device’s function include a time-of-day clock, an alarm, a one-hundred-year calendar, a square wave generator, programmable interrupts, and 114 bytes of nonvolatile static RAM. The device uses CMOS technology and interfaces with most microprocessor buses. The device consumes very little power.

Pinouts :

W85C178 datasheet


1. 14 bytes of clock and control / status registers
2. 128 bytes of general nonvolatile storage
3. BCD or binary representation of time, calendar, and alarm registers
4. Counts seconds, minutes, hours, days of the week, days of the month, momths, years
5. 12-hour to 24-hour clock with AM and PM in 12-hour mode
6. Daylight saving time option
7. Automatic leap-year adjustment
8. Programmable square wave output signal
7. Time base input option : 4.194304 MHz, 1.048576 MHz, 32.768 kHz
8. Automatic end of month recognition


Other data sheets within the file : MC146818A, 85C178

W85C178 Datasheet PDF Download

W85C178 pdf

NE555N Datasheet – General-purpose Timer

Part Number : NE555N

Function : General-purpose Single Bipolar Timer

Package :  DIP 8 Pin Type

Manufacturers : STMicroelectronics


NE555N Timer IC


The NE555, NE555N, SA555, and SE555 monolithic timing circuits are highly stable controllers capable of producing accurate time delays or oscillation. In the time delay mode of operation, the time is
precisely controlled by one external resistor and capacitor. For a stable operation as an oscillator, the free running frequency and the duty cycle are both accurately controlled with two external resistors and one capacitor. The circuit may be triggered and reset on falling waveforms, and the output structure can source or sink up to 200 mA. […]


NE555N datasheet pinout


1. Low turn-off time
2. Maximum operating frequency greater than 500 kHz
3. Timing from microseconds to hours
4. Operates in both astable and monostable modes
5. Output can source or sink up to 200 mA
6. Adjustable duty cycle
7. TTL compatible
8. Temperature stability of 0.005% per °C

NE555N ordering information

NE555N Datasheet