R2033K Datasheet, PDF (43/50 Pages) RICOH electronics devices division – 3 wire interface Real-Time Clock ICs

R2033K/T
• Connection of INTR Pin
The INTR pin follows the N-channel open drain output logic and contains no protective diode on the power
supply side. As such, it can be connected to a pull-up resistor of up to 5.5v regardless of supply voltage.
INTR
OSCIN
OSCOUT
VDD
VSS
System power supply
A
*1)
B
Backup power supply
32768Hz
*1) Depending on whether the INTR pin is
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.
• Connection of 32KOUT Pin
As the 32KOUT pin is CMOS output, the supply voltage of the R2033K/T and any devices to be connected
should be the same. When the device is powered down, the 32KOUT output pin should be disabled.
When the CLKC pin is connected to the system power supply through the pull-up resistor, the pull-up resistor
should be 0Ω to 10kΩ, and the 32KOUT pin should be connect to the host device through the resistor (approx.
10kΩ)
CLKC
32KOUT
VDD
VSS
R3111
XXXXC
CPU Power Supply
CLKC
32KOUT
Back-up Power Supply
0 to 10KΩ ^{CPU Power Supply}
CPU
Approx.10KΩ
Back-up Power supply
VDD
VSS
43