Real-time Clock IC
SM8577B
NIPPON PRECISION CIRCUITS INC.
Real-time Clock IC
OVERVIEW
The SM8577B is a CMOS serial-interface type realtim...
Description
SM8577B
NIPPON PRECISION CIRCUITS INC.
Real-time Clock IC
OVERVIEW
The SM8577B is a CMOS serial-interface type realtime clock IC that operates at 32.768 kHz. It employs a 3-line serial interface to transfer time and date data. It incorporates a supply-voltage detect function to determine data validity/invalidity. It features an output interrupt with 32 kHz or 1 Hz output frequency. It is available in 8-pin SOPs.
PINOUT
CE DATA CLK FOUT
1
8
VDD XTN XT VSS
8577B
FEATURES
s s s s s
4
5
s s s s s
2.5 to 5.5 V operating voltage range 1.0 µA at 3.0 V (typ) current consumption 3-line serial interface 1.7 ± 0.3 V supply voltage detection threshold Timer counters for second, minute, hour, day, day of the week, month, and year Automatic leap-year calendar adjustment 32.768 kHz and 1 Hz output interrupt selectable Crystal oscillator circuit built-in (CD built-in) 24-hour time mode 8-pin SOP
PACKAGE DIMENSIONS
Unit: mm
8-pin SOP
0.15− 0.05
+ 0.10
4.4 0.2 6.2 0.3
5.2 0.3
0 to 10∞
ORDERING INFOMATION
Device SM8577BS Package 8pin SOP
0.4 0.1
NIPPON PRECISION CIRCUITS—1
0.05 0.05
1.5 0.1
1.27
4.4 0.2
SM8577B
BLOCK DIAGRAM
VDD VSS
XT XTN
OSC
Divider
Timer Counter
FOUT
Output Controller Voltage Detect
Shift Register
DATA CLK CE
I/O Controller
Controll Circuit
PIN DESCRIPTION
Number 1 2 3 Name CE DATA CLK I/O I I/O I Description Chip enable. With pull-down resistor built-in. HIGH: Enable LOW: DATA goes high impedance; input on CLK and DATA stops; and the TM ...
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