8051 Microcontroller

• A dual version of NE556 consists of two precision timers that operate in both monostable and astable modes.
• It is specified for operation from 4.5 V to 16 V.
• TTL compatible output which can source or sink current of up to 150mA.
• Adjustable duty cycle.
• It can produce a timing delay from microseconds to hours.
• The operating temperature range is from 0 to 70 degrees Celsius.
• It has temperature stability better than 0.005% per C.

The DS1307 serial real-time clock (RTC) is a lowpower, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM. Address and data are transferred serially through an I2C, bidirectional bus. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. The DS1307 has a built-in power-sense circuit that detects power failures and automatically switches to the backup supply. Timekeeping operation continues while the part operates from the backup supply.