NR8576 series
Real-time Clock Modules
OVERVIEW
The NR8576 series devices are serial-interface type real-time clock module ICs with built-in crystal oscillator
elements. They feature timer counter circuits that keep track of time from the current second to the current
year, automatic leap-year adjustment, and a supply voltage detect function. Also, a 32.768kHz/1Hz select output function is incorporated for independent hardware control. They are available in compact 14-pin SOPs
(NR8576A×) and miniature 18-pin SOPs (NR8576B×).
FEATURES
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Crystal oscillator element built-in for adjustmentfree use
Timer counters for second, minute, hour, day, day
of the week, month, and year
2.5 to 5.5V operating voltage range
1.7 ± 0.3V supply voltage detection threshold
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1.0µA at 3.0V (typ) current consumption
Automatic leap-year calendar adjustment
32.768kHz and 1Hz output selectable
Package
• 14-pin SOP (NR8576A×)
• 18-pin SOP (NR8576B×)
PINOUTS
14-pin SOP
18-pin SOP
NC
1
18
NC
NC
2
17
NC
3
16
NC
4
15
NC
5
14
VDD
VSS
1
14
FOUT
NC
2
13
NC
NC
CE
3
12
NC
NC
FOE
FSEL
4
11
DATA
WR
5
10
CLK
9
8
7
VDD
13
NC
12
CLK
8
11
DATA
VSS
NC
6
6
7
CE
FOE
WR
FSEL
9
10
FOUT
NC
PACKAGE DIMENSIONS (Unit: mm)
18-pin SOP
0.35 0.1
5.4
1.8 0.1
0.15
1.27
7.8 0.2
0 10
0.6 0.2
5.0
7.4 0.2
0.10 0.05
3.2 0.1
1.27
11.4 0.2
0 10
0.05 0.05
10.1 0.2
0.6 0.2
14-pin SOP
0.15
0.4 0.1
SERIES CONFIGURATION
Device
NR8576AA
NR8576AB
NR8576BA
NR8576BB
Package
14-pin SOP
14-pin SOP
18-pin SOP
18-pin SOP
Frequency deviation
5 ± 12 ppm
5 ± 23 ppm
5 ± 12 ppm
5 ± 23 ppm
SEIKO NPC CORPORATOIN—1
