PT7C4302 Datasheet, PDF (3/16 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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Pin Configuration
PT7C4302
1 VCC2
VCC1 8
2 X1
SCLK 7
3 X2
I/O ⁶
4 _GND
RST ⁵
DIP-8
SOIC-8
Pin Description
Pin no.
1
Pin
Type
Description
VCC2
P Primary power. When VCC2 is greater than VCC1 + 0.2V, VCC2 will power the PT7C4302.
2
X1
I Oscillator Circuit Input. Together with X2, 32.768kHz crystal is connected between them.
3
X2
O Oscillator Circuit Output. Together with X1, 32.768kHz crystal is connected between them.
4
GND
P Ground.
5
RST
I
Reset. The reset signal must be asserted high during a read or a write. This pin has a 40kΩ
internal pull-down resistor.
6
I/O
I/O
Serial Data Input/Output. I/O is the input/output pin for the 3-wire serial interface. The pin
has a 40kΩ internal pull-down resistor.
7
SCLK
I
Serial Clock Input. SCLK is used to synchronize data movement on the 3-wire serial
interface. The pin has a 40kΩ internal pull-down resistor.
Backup power. When VCC2 is less than VCC1, VCC1 will power the PT7C4302. VCC1
provides low-power operation in single supply and battery-operated systems as well as low
8
VCC1
P power battery backup. In systems using the trickle charger, the rechargeable energy source is
connected to this pin. UL recognized to ensure against reverse charging current when used in
conjunction with a lithium battery.
PT0225(11/05)
3
Ver: 0