RV5C339A Datasheet, PDF (42/51 Pages) RICOH electronics devices division – 3-WIRE SERIAL INTERFACE REAL-TIME CLOCK ICs WITH VOLTAGE MONITORING FUNCTION

RV5C339A
6.2 Connection of INTRA and INTRB Pins
The INTRA and INTRB pins follow the N-channel open drain output logic and contain no protective diode on the
power supply side. As such, it can be connected to a pull-up resistor of up to 5.5 volts regardless of supply voltage.
RV5C339A
INTRA or INTRB
OSCIN
OSCOUT
VDD
VSS
System power supply
A
B ^*1
32.768kHz
Backup battery
*1) Depending on whether the INTRA and INTRB pins are to be
used during battery backup, it should be connected to a pull-up
resistor at the following different positions:
1) Position A in the left diagram when it is not to be used during
battery backup.
2) Position B in the left diagram when it is to be used during
battery backup.
6.3 Connection of 32KOUT Pin
The 32KOUT pin follows the Nch. open drain output and contains no protective diode on the power supply side. As
such, it can be connected to a device with a supply voltage of up to 5.5 volts regardless of supply voltage, provided
that such connection involves considerations for the supply current requirements of a pull-up resistor, which can be
roughly calculated by the following equation:
I=0.5×(VDD or VCC)/ Rp
RV5C339A
32KOUT
OSCIN
OSCOUT
VDD
VSS
System power supply (VCC)
Rp
A
B ^*1
32.768kHz
Backup battery
(VDD)
*1) Depending on whether the 32KOUT pin is to be used during
battery backup, it should be connected to a pull-up resistor at
the following different positions:
1) Position A in the left diagram when it is not to be used during
battery backup.
2) Position B in the left diagram when it is to be used during
battery backup.
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