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 out-
put function is incorporated for independent hardware control. They are available in compact 14-pin SOPs
(NR8576A
×
) and miniature 18-pin SOPs (NR8576B
×
).
FEATURES
I
I
I
I
Crystal oscillator element built-in for adjustment-
free 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
I
I
I
I
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
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
NC
NC
NC
NC
VDD
NC
CLK
DATA
FOUT
VSS
NC
CE
FSEL
WR
FOE
NC
1
2
3
4
5
6
7
14
13
12
11
10
9
8
FOUT
NC
NC
DATA
CLK
VDD
NC
NC
NC
NC
FOE
WR
FSEL
CE
VSS
PACKAGE DIMENSIONS
(Unit: mm)
14-pin SOP
10.1 0.2
0 10
18-pin SOP
11.4 0.2
0 10
7.4 0.2
7.8 0.2
5.0
5.4
0.10 0.05
1.8 0.1
1.27
0.35 0.1
3.2 0.1
1.27
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
0.05 0.05
0.15
0.6 0.2
0.15
0.6 0.2
NPC [ NIPPON PRECISION CIRCUITS INC ]
