SLVUCK8 September 2022
3.1 Output Voltage Setpoint
To change the output voltage of the EVM, change the value of resistor R7 (RUPPER) and R9 (RLOWER). The value of R7 and R9 for a specific output voltage can be calculated using Equation 1 and refer to Table 3-1 for some recommendation values. See the TPS56C231 3.8-V to 17-V Input , 12-A Synchronous Step-Down Converter data sheet. See Table 3-1 to set the switching frequency.
Equation 1. 
Table 3-1 Recommended Component Values
| VOUT (V) | RLOWER (kΩ) | RUPPER (kΩ) | fSW (kHz) | LOUT (µH) | COUT(min) (µF) | COUT(max) (µF) | CFF (PF) |
|---|---|---|---|---|---|---|---|
| 0.6 | 10 | 0 | 400 | 0.68 | 300 | 500 | — |
800 | 0.47 | 100 | 500 | — | |||
1200 | 0.33 | 88 | 500 | — | |||
| 1.2 | 10 | 10 | 400 | 1.2 | 100 | 500 | — |
800 | 0.68 | 88 | 500 | — | |||
1200 | 0.47 | 88 | 500 | — | |||
| 3.3 | 10 | 45.3 | 400 | 2.4 | 88 | 500 | 100-220 |
800 | 1.5 | 88 | 500 | 100-220 | |||
1200 | 1.2 | 88 | 500 | 100-220 | |||
| 5.5 | 10 | 82.5 | 400 | 3.3 | 88 | 500 | 100-220 |
800 | 2.4 | 88 | 500 | 100-220 | |||
1200 | 1.5 | 88 | 700 | 100-220 |