Rev.1.2_00
S-35390A
2-WIRE REAL-TIME CLOCK
The S-35390A is a low-current-consumption 2-wire CMOS real-time clock IC
that features a wide operating voltage range (1.3 V to 5.5 V) and can be
driven on a variety of supply voltages, from a main supply to a backup
supply. The time keeping current consumption of 0.25 µA and minimum
time keeping operation voltage of 1.1 V enable greatly increased battery
duration.
In a system that operates on a backup battery, the free register incorporated
in the real-time clock can be used for the user backup memory function.
The user register can hold data on a supply voltage as low as 1.2 V (min.),
so the data stored in the register before the main power supply was cut can
be called any time after the voltage is restored.
This product also includes a clock adjustment function that enables wideranging correction of deviation in the frequency of the crystal oscillator at a
minimum resolution of 1 ppm. Also, by combining this function with a
temperature sensor, the clock adjustment value can be set in accordance
with changes in the temperature, which makes it possible to realize a clock
function that retains a high degree of accuracy regardless of temperature
variation.
Features
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Low current consumption:
0.25 µA typ. (VDD = 3.0 V, Ta = 25°C)
Wide operating voltage range:
1.3 to 5.5 V
Minimum time keeping operation voltage: 1.1 V
Built-in clock adjustment function
Built-in free user register
2-wire (I2C-BUS)*1 CPU interface
Built-in alarm interrupter
Built-in flag generator at power down or power on
Auto calendar up to the year 2099, automatic leap year calculation function
Built-in constant voltage circuit
Built-in 32 kHz crystal oscillator circuit (Cd built in, Cg external)
Package: 8-pin SOP (JEDEC), 8-pin TSSOP, SNT-8A
*1. I2C-BUS is a trademark of Philips Electronics N.V.
Applications
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Digital still cameras
Digital video cameras
Electronic power meters
DVD recorders
TVs, VCRs
PHS
Mobile phones
Car navigation
Seiko Instruments Inc.
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