The Rx5C338A are CMOS real-time clock ICs connected to the CPU by three signal lines CE (Chip Enable), SCLK (Serial Clock), and SIO (Serial Input/Output), and configured to perform serial transmission of time and calendar data to the CPU. These models incorporate different functional circuits.
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. 0.35 µA 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 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. SSOP10 and SSOP10G packages are available.
|Timekeeping supply voltage||1.45 to 5.5 V|
|Supply Current||Typ. 0.35 µA (VDD=3V)|
|Connected to the CPU||Three signal lines (SCLK, SIO, and CE), Maximum clock frequency of 2 MHz (with VDD of 5 V)|
|Functions||Time counters (counting hours, minutes, and seconds) and calendar counters (counting years, months, days, and weeks) (in BCD format)|
|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|
|2 alarm circuits (Alarm_W for week , hour , and minute alarm settings and Alarm_D for hour and minute alarm settings)|
|Oscillation halt sensing circuit which can be used to judge the validity of internal data|
|Supply voltage monitoring circuit with two supply voltage monitoring threshold settings|
|Automatic identification of leap years up to the year 2099|
|Selectable 12-hour and 24-hour mode settings|
|Clock Output||32-kHz (CMOS output, equipped with a control pin)|
|Built-in Circuits||Oscillation stabilization capacitors (CG and CD)|
|High precision oscillation adjustment|
|Product Name||Package||Quantity per Reel|