The RTC 3 Click Board™ is based on the BQ32000, a real time clock with an integrated trickle charge circuit for automatic switchover to a backup power supply (the circuit maintains the backup charge with an onboard super capacitor). The clock frequency is derived from an onboard 32.768KHz oscillator. The RTC 3 Click Board™ communicates with the target board microcontroller through mikroBUS I2C lines: SCL, SDA. In addition, the INT pin serves as a configurable interrupt output. The board is designed to use a 3.3V power supply only.
IC/module: BQ32000
BQ32000 is a real time clock/calendar chip that includes an automatic backup supply that can be implemented using a capacitor or non-rechargeable battery. The integrated trickle charger enable automatic switchover to backup supply. It also includes an integrated oscillator-fail detection flag that indicates the status of the RTC oscillator. The STOP bit allows the host processor to put the oscillator out of action.
I2C Interface
RTC3 Click Board™ communicates with the target board MCU through a two-wire serial interface (mikroBUS I2C). The bus includes a data line (SDA) and a clock line (SCL) with off-chip pullup resistors. The INT pin serves as a configurable interrupt output.
Integrated Trickle Charger
RTC3 Click Board™ includes a trickle charge circuit that maintains the charge of the backup supply when using a super capacitor. It is put into operation as a series of three switches that are independently controlled. Even though the trickle charge circuit is projected for use with super capacitors, it can also be used with a rechargeable battery under specified circumstances.