PT7C433833 Datasheet, PDF (2/17 Pages) Pericom Semiconductor Corporation – Real-time Clock Module (I2C Bus)

PT7C433833
Real-time Clock Module (I²C Bus)
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Pin Assignment
Pin Description
PT7C4338
1 X1
VCC 8
2 X2
SQW/OUT 7
3 VBAT
SCL 6
4 _GND
SDA ⁵
SOIC-8
MSOP-8
Pin no.
1
2
6
Pin
Type
Description
32.768kHz Crystal Connections. The internal oscillator circuitry is designed for operation with
X1
I _{a crystal having a specified load capacitance (CL) of 12.5pF. Pin X1 is the input to the oscillator}
and can optionally be connected to an external 32.768kHz oscillator. The output of the internal
oscillator, pin X2, is floated if an external oscillator is connected to pin X1. An external
X2
O 32.768kHz oscillator can also drive the PT7C4338. In this configuration, the X1 pin is connected
to the external oscillator signal and the X2 pin is floated.
SCL
I Serial Clock Input. SCL is used to synchronize data movement on the I²C serial interface.
5
SDA
I/O
Serial Data Input/Output. SDA is the input/output pin for the 2-wire serial interface. The SDA
pin is open-drain output and requires an external pull-up resistor.
Square-Wave/Output Driver. When enabled and the SQWE bit set to 1, the SQW/OUT pin
7
SQW/OUT O outputs one of four square-wave frequencies (1Hz, 4kHz, 8kHz, 32kHz). It is open drain and
requires an external pull up resistor. Operates with either VCC or VBAT applied.
Supply Voltage. When voltage is applied within normal limits, the device is fully accessible and
8
VCC
P
data can be written and read. When a backup supply is connected to the device and VCC is
below VPF, reads and writes are inhibited. However, the timekeeping function continues
unaffected by the lower input voltage.
+3V Battery Input. Backup supply input for any standard 3V lithium cell or other energy
3
VBAT
P
source. Battery voltage must be held between the minimum and maximum limits for proper
operation. If a backup supply is not required, VBAT must be grounded. UL recognized to ensure
against reverse charging when used with a lithium battery.
Ground. DC power is provided to the device on these pins. VCC is the primary power input.
When voltage is applied within normal limits, the device is fully accessible and data can be
4
GND
P written and read. When a backup supply is connected to the device and VCC is below VPF, reads
and writes are inhibited. However, the timekeeping function continues unaffected by the lower
input voltage.
12-07-0001
PT0321-6 07/04/12
2