The recommended power-up sequence is to apply VCC first, followed by VBAT. This ensures that the internal oscillator is stabilized before the RTC starts counting.
To ensure that the DS1338U-33+T&R retains its clock data during power-down, connect a battery to the VBAT pin. This allows the internal oscillator to continue running, maintaining the clock data.
The maximum frequency for the SQW/OUT pin is 1 Hz to 64 kHz. However, the frequency can be programmed to be as low as 1 Hz or as high as 32.768 kHz in 1 Hz increments.
No, the DS1338U-33+T&R is designed to operate at 3.3V. Applying 5V to the VCC pin may damage the device.
To reset the DS1338U-33+T&R to its default state, pull the RST pin low for at least 100 ns. This resets the device to its power-on default state.