Vout3 of ADP1031 not used

Hi baggio,

The inverter/VOUT3 on the ADP1031 can be disable by:

1. removing the inductor connected to SW3, SW3 should be floating.
2. VOUT3 should be tied to GND.
3. FB3 must be supplied within this range 0.8V < VFB3 < 0.8V +10% in reference to VOUT3/GND to disable the SW3 from turning on.
   1. The voltage on FB3 can be generated from VOUT2 through resistor dividers. For example, for 5V VOUT2 – use 10kohm across the FB3 and VOUT3/GND. Use 51.5kohm resistor across VOUT2 and FB3. This resistor divider combination will give 0.818V on FB3 in reference to VOUT3/GND.

This will not only disable the switching of the SW3 but also retain the PWRGD functionality.

Thanks,

Jefferson

Hi baggio,

The inverter/VOUT3 on the ADP1031 can be disable by:

1. removing the inductor connected to SW3, SW3 should be floating.
2. VOUT3 should be tied to GND.
3. FB3 must be supplied within this range 0.8V < VFB3 < 0.8V +10% in reference to VOUT3/GND to disable the SW3 from turning on.
   1. The voltage on FB3 can be generated from VOUT2 through resistor dividers. For example, for 5V VOUT2 – use 10kohm across the FB3 and VOUT3/GND. Use 51.5kohm resistor across VOUT2 and FB3. This resistor divider combination will give 0.818V on FB3 in reference to VOUT3/GND.

This will not only disable the switching of the SW3 but also retain the PWRGD functionality.

Thanks,

Jefferson