Other Parts Discussed in Thread: TPS63027,
From TPS63027 datasheet results a maximum Vout = 5V, without a clear specification about current. So we bought TPS63027EVM-870 EV board, changing feedback resistors (R1 and R2 in datasheet) according to these three attempts:
ATTEMPT 1: R1 = 430 kOhm, R2 = 82 KOhm;
ATTEMPT 2: R1 = 1000 KOhm, R2 = 180 KOhm (the attempt resulted from datasheet advice to mantain R2 in range of 180 KOhm);
ATTEMPT 3: R1= 523 Kohm, R2 = 100 Kohm (suggested by TI technical support).
However, the result still remains the same: in output we obtain 4,8 V in all cases (in attempt 2, the resistors sizing lead to Vout = 5,2V !). Besides, with a load of 0.5A, we get this value after a very slow ramp, during at least 1 hour (from a starting Vout = 3.3).
In the setup we provide the supply voltage (from 4.5V to 5.4V) to the board, whose output is connected to 10 Ohm resistors (in photo are shown two resistors in parallel, but we tried also a single resistor. Respectively, outputs current are 1A and 0.5A). The current values lies on datasheet rated range (measured by bench power supply), instead output voltage is measured by bench multimeter.
In conclusion, the trouble is that is obtained a lower voltage than indicated by datasheet (4,8V), through a too much slow ramp (last of two hours, regardless about the load).
So, in your opinion, how can we fix this?
