Rx5C348A/B Specifications
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| The Rx5C348A/B are CMOS real-time clock ICs connected to the CPU by four signal lines,
CE, SCLK, SI, SO, 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 interrupt circuits generate interrupt signals at preset times. As the oscillation
circuit is driven under constant voltage, fluctuation of the oscillator frequency due to supply voltage is
small, and the time keeping current is small(TYP. 0.35ľA at 3V: Rx5C348A, TYP.0.55ľA at 3V: Rx5C348B). 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 32.768kHz clock output function (N-channel open drain output)
is intended to output sub-clock pulses for the external microcomputer. The 32-kHz clock circuit can be disabled
by certain register settings for the Rx5C348A but cannot be disabled by any register settings for the Rx5C348B.
The oscillation adjustment circuit is intended to adjust time counts with high precision by correcting deviations
in the oscillation frequency of the crystal oscillator. These models come in an ultra-compact SSOP10 (RS5C348A/B), SSOP10G (RV5C348A/B), TSSOP10G (RT5C348B) |
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Package |
32-kHz Clock Output |
| RS5C348A |
SSOP10 (Pin
Pitch 0.5mm, Height1.25mm,6.4mm ×3.5mm) |
Controllable by command |
| RS5C348B |
Keeping output enabled |
| RV5C348A |
SSOP10G (Pin
Pitch 0.5mm, Height1.2mm,4.0mm ×2.9mm) |
Controllable by command |
| RV5C348B |
Keeping output enabled |
| RT5C348B |
TSSOP10G (Pin
Pitch 0.5mm, Height0.85mm,4.0mm ×2.9mm) |
Keeping output enabled |
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 Timekeeping
supply voltage ranging from 1.45 to 5.5V |
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| Low
supply current |
Rx5C348A: 0.35 µA TYP (0.8 µA MAX) at VDD=3V
Rx5C348B: 0.55 µA TYP (1.0 µA MAX) at VDD=3V |
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| Only
four signal lines (CE, SCLK, SI, and SO) required for connection to the CPU. |
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| Maximum
clock frequency of 2MHz (with VDD=5V) |
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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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| 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 |
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| 2
alarm interrupt 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 output circuit (Nch. open drain output) |
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Rx5C348A is designed to disable 32-kHz clock output in response to a command from the host computer and the
Rx5C348B is designed to keep 32-kHz output enabled. |
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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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| Ultra-compact SSOP10 (RS5C348A/B), SSOP10G (RV5C348A/B), TSSOP10G (RT5C348B) |
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| CMOS
process |
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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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Product Catalog
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| Selection guide is available for download in PDF format. |
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