Hi,
we are working with a customer that wishes to minimize capacitance on their PCB and have determined that they do not need the B0 rail but they do want to keep using this particular PMIC. Is it possible to leave pins 8,9,10 floating or grounded and disable that rail?
If not, please define the minimum capacitance that is required for overall device performance if the B0 rail is to be unused.
Respectfully,
Blake Kisshauer
This PMIC uses the same enable pin (EN1) to control all 4 bucks. To successfully leave buck0 unused/unconnected, you would need to do the following:
For the PCB:
1. Connect FB_B0 to GND.
2. Leave SW_B0 unconnected/floating.
On boot:
1. Pull EN1 signal low immediately upon boot.
2. Write to the BUCK0_CTRL1 register:
Change EN_BUCK0 to 0x00 and change EN_PIN_CTRL0 to 0x00.
3. EN1 can be pulled high now and the PMIC can proceed with the power sequencing, while leaving BUCK0 disabled.
Kind regards,
Conner Gillette
