Hello,
I am using TPS74601 to generate 3.3V o/p with i/p from 3.7V to 5V. I am not able to get expected o/p. Even I change values of F/B resistors R18 to 33K & R20 to 6.6K, Still o/p is not 3.3V constant. F/B pin voltage is stable 0.55V. Below are measured values at TP19. What can be wrong in this ?
| R20 & R18 | o/p Voltages (V) | ||
| Resistor Combination | @3.7 ip | @4.3 i/p | @5 i/p |
| 4.7k & 23.5K | 1.9 +/- 0.2 | 2.5 +/- 0.2 | 3.2 +/- 0.2 |
| 1K & 5K | 1.9 +/- 0.2 | 2.5 +/- 0.2 | 3.2 +/- 0.2 |
| 6.6k & 33K | 1.9 +/- 0.2 | 2.5 +/- 0.2 | 3.2 +/- 0.2 |
| 55K & 275K | 1.9 +/- 0.2 | 2.5 +/- 0.2 | 3.2 +/- 0.2 |
