How do I use external clock when low standby current is required for the S6BP20xA family?
To use external clock with the S6BP20xA family:
- Choose a part number (MPN) for the S6BP20xA family with SYNC_IN function (See Product Lineup in the device datasheet).
- Connect MODE pin to GND.
- Set the SYNC pin to L in the system standby condition, and feed external clock signal to the SYNC pin after the system wakes up. PMIC will now operate in automatic PWM/PFM mode with internal clock to reduce quiescent current in system standby, and in fixed PWM mode with external clock signal during system wake-up.
To ensure normal operation when using external clock, the internal clock frequency set by RT pin resistor (RRT) must be lower than the minimum of the external clock frequency (Fex_min) applied. Choose a RRT value using the following equation:
Fex_min × 21.7×10−12