SM8578BV
Real-time Clock IC
OVERVIEW
The SM8578BV is a serial interface, real-time clock IC that uses a 32.768kHz crystal oscillator for its reference timing. It comprises second-counter to year-counter clock and calendar circuits that feature automatic
leap-year adjustment, alarm and timer interrupt functions, as well as oscillator stop, timer reloading, and other
detection functions. Data is transferred to and from an external controller using a 3-wire serial interface. It is
available in compact 8-pin VSOP packages, making it ideal for use in all types of portable, hand-held equipment.
FEATURES
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ORDERING INFORMATION,
VDD
DATA
XTN
XT
VSS
CLK
CE
5
4
PACKAGE DIMENSIONS
(Unit: mm)
Device
Package
SM8578BV
8-pin VSOP
0 to 10 °
0.5 ± 0.2
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8
1
6.4 ± 0.3
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INTN
4.4 ± 0.2
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(Top view)
+ 0.1
0.05
0.15 −
0.575TYP
3.1 ± 0.3
1.15 ± 0.05
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1.6 to 5.5V wide operating voltage range
0.5µA (typ.) current consumption
(VDD = 3.0V, CE = Low)
3-wire serial interface control
Day, day-of-week, hour, and minute alarm interrupt function
1/4096 seconds to 255 minutes presettable interval
timer interrupt function
Time update detection function
Abnormal oscillation detection function
Automatic leap-year adjustment function
(Western and Japanese calendars)
Oscillator capacitor CD built-in
Molybdenum-gate CMOS process
Miniature 8-pin VSOP package
0.65
0.10
0.1 ± 0.05
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PINOUT
0.22 ± 0.1
0.12 M
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