PT7C4372A Datasheet, PDF (1/30 Pages) Pericom Semiconductor Corporation – Real-time Clock Module

PT7C4372A/4372C
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Real-time Clock Module (I²C Bus)
Product Features
Product Description
• External quartz oscillator 32.000kHz and 32.768kHz
selectable.
• Supports I²C-Bus's high speed mode (400 kHz)
• Includes time (Hour/Minute/Second) and calendar
(Year/Month/Date/Day) counter functions (BCD
code)
• Select between 12-hr and 24-hr clock display
• Auto calculation of leap years until 2099
• Built-in high-precision clock precision control logic
• Interrupt generation function (cycle time range: 1
month to 0.5 seconds, includes interrupt flags and
interrupt stop function)
• Alarm functions (Alarm_A: Day/Hour/Min)
• 32-kHz clock output (/INTB output)
• Oscillation stop detection function (used to determine
presence of internal data)
• Wide Time keeping voltage range: 1.3 V to 6 V
• Wide interface voltage range: 1.8 V to 6 V
• Low current consumption: 0.4 µA/3.0 V (Typ.)
PT7C4372A/C are I²C bus interface-compliant real-time
clocks that have been adjusted for high precision. In
addition to providing a function for generating six types
of interrupts, a dual alarm function, an oscillation stop
detection function (used to determine presence of valid
internal data at power-on), they includes a digital clock
precision adjustment function that can be used to set
various levels of precision.
Since the internal oscillation circuit is driven at a
constant voltage, 32-kHz clock output is stable and free
of voltage fluctuation effects.
Table 1 shows the diverse functions of the two RTC
circuits. More details are shown in section Overview of
Functions.
Table 1. Diverse functions of RTC circuits
Item
Function
1
Clock
2
Clock adjustment
3
Period interrupt
4
Alarm
5
Oscillation detect
6
32-kHz clock output
7
I²C bus interface with CPU
8
Crystal
PT7C4372A/4372C

 Unit 3.051ppm for 32.768kHz crystal;
3.125ppm for 32.000kHz crystal
 Output from /INTA and /INTB
 /INTA: Alarm_A; /INTB: Alarm_B

 via /INTB enabled by register

 External, 32.768kHz or 32.000kHz selectable
12-07-0001
PT0150-8 07/04/12
1