The BUCK regulator configuration pins VSET1 and VSET2 are available on pin header P10 (labeled CONFIG) for custom BUCK startup configuration through compatible resistors values.
Figure 1. VSET schematic
The VSET1 and VSET2 pins are only effective at power up. The external resistor (maximum 5% tolerance) defines the default output voltage setting as found in the following table.
| Resistor value | Output voltage | |
|---|---|---|
| VOUT1 | VOUT2 | |
| < 100 Ω (grounded) | 0 V (OFF) | 0 V (OFF) |
| 4.7 kΩ | 1.0 V | 1.8 V |
| 10 kΩ | 1.2 V | 2.0 V |
| 22 kΩ | 1.5 V | 2.2 V |
| 47 kΩ | 1.8 V (RSET1) | 2.4 V |
| 68 kΩ | 2.0 V | 2.5 V |
| 100 kΩ | 2.2 V | 2.7 V |
| 150 kΩ | 2.5 V | 3.0 V (RSET2) |
| 250 kΩ to 500 kΩ | 2.7 V | 3.3 V |
Note: When using external VSET resistors remember to disconnect the default
VSET jumpers on pin headers P13 and P14.