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PT7C4302 Datasheet, PDF (1/16 Pages) Pericom Semiconductor Corporation – Real-time Clock Module (3-wire Interface)
Data Sheet
PT7C4302
Real-time Clock Module (3-wire Interface)
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Features
Description
• Using external 32.768kHz quartz crystal
• Real-time clock (RTC) counts seconds, minutes
hours, date of the month, month, day of the week,
and year with leap-year compensation valid up to
2099
• 31-byte, nonvolatile (NV) RAM for data storage
• 2.0V to 5.5V full operation
• Uses less than 300nA at 2.0V
• Simple 3-wire interface
• Serial I/O for minimum pin count
• Burst mode for reading/writing successive addresses
in clock/RAM
• TTL-compatible (VCC = 5V)
• Optional industrial temperature range: -40°C to
+85°C
• Battery backup
• Trickle charger on chip for rechargeable energy
source backup
The PT7C4302 serial real-time clock is a low-
power clock/calendar with a programmable square-wave
output and 31 bytes of nonvolatile RAM.
Address and data are transferred serially via a 3-
wire bus. The clock/calendar provides seconds, minutes,
hours, day, date, month, and year information. The date
at the end of the month 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.
Table 1 shows the basic functions of PT7C4302.
More details are shown in section: overview of functions.
Ordering Information
Part Number
Package
PT7C4302P
8-Pin DIP
PT7C4302W
8-Pin SOIC
Note: Lead free package is available by adding “E” after each
part number. For example: PT7C4302PE.
Table 1 Basic functions of PT7C4302
Item
Function
Source: Crystal: 32.768kHz
1
Oscillator Oscillator enable/disable
Oscillator fail detect
2
Time
Time display
Century bit
12-hour
24-hour
Time count chain enable/disable
2-wire I2C bus
Communicat
3
3-wire bus
ion
Burst mode
Write protection
4
Control
External clock test mode
Power-on reset override
5
RAM
6
Charger
7
Battery backup
PT7C4302
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