| The RV5C387A is a CMOS real-time clock IC connected to the CPU by two signal, SCL and
SDA, and configured to perform serial transmission of time and calendar data to the CPU. The periodic interrupt
circuit is configured to generate interrupt signals with six selectable interrupts ranging from 0.5 seconds
to 1 month. The 2 alarm circuits generate interrupt signals at preset times. The oscillation circuit is driven
under constant voltage so that fluctuations in oscillation frequency due to voltage are small and supply current
is also small (TYP. 0.35µA for the RV5C387A at 3 volts). The oscillation halt sensing circuit can be
used to judge the validity of internal data in such events as power-on. The supply voltage monitoring circuit
is configured to record a drop in supply voltage below two selectable supply voltage monitoring threshold settings.
The 32-kHz clock output function (Nch. open drain) is intended to output sub-clock pulses for the external
microcomputer. The oscillation adjustment circuit is intended to adjust time counts with high precision by
correcting deviations in the oscillation frequency of the crystal oscillator. The 32-kHz clock circuit can
be disabled by certain register settings. This model comes in an ultra-compact 10-pin
SSOP-G (with a height of 1.20mm and a pin pitch of 0.5mm). |
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 Timekeeping
supply voltage ranging from 1.45 to 5.5 volts |
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| Low
supply current |
TYP. 0.35µA (MAX. 0.8µA) at 3 volts |
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| Only
two signal lines (SCL, SDA) required for connection to the CPU. (I2C bus compatible, 400kHz at VDD>=2.5V,
address 7bits) |
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| Time
counters (counting hours, minutes, and seconds) and calendar counters (counting years, months, days, and weeks)
(in BCD format) |
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| 1900/2000
identification bit for Year 2000 compliance |
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| Interrupt
circuit configured to generate interrupt signals (with interrupts ranging from 0.5 seconds to 1 month) to the
CPU and provided with an interrupt flag and an interrupt halt circuit |
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| 2
alarm circuits (Alarm_W for week, hour, and minute alarm settings and Alarm_D for hour and minute alarm settings) |
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| 32-kHz
clock circuit (Nch. open drain output) |
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| Oscillation
halt sensing circuit which can be used to judge the validity of internal data |
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| Supply
voltage monitoring circuit with two supply voltage monitoring threshold settings |
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| Automatic
identification of leap years up to the year 2099 |
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| Selectable
12-hour and 24-hour mode settings |
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| Built-in
oscillation stabilization capacitors (CG and CD) |
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| High
precision oscillation adjustment circuit |
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| CMOS
process |
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| Ultra-compact 10-pin
SSOP-G (with a height of 1.20mm and size 4.0mm×2.9mm) |
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Communication devices (multi function phone, portable phone, PHS
or pager) |
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OA devices (fax, portable fax)
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Computer (desk-top and mobile PC, portable word-processor, PDA, electric note
or video game) |
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AV components (portable audio unit, video camera,camera, digital camera or remote
controller) |
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Home appliances (rice cooker, electric oven) |
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Other (car navigation system, multi-function watch) |
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