I am considering a step down converter TPS82740B, which is set for Vout = 3V. The system is powered from a Li-ion battery Vin = 3.2- 4.2V. The total load current requirement is typically around 100mA but can go up to 150-160mA for 20-30min. This presents a problem because according to the recommended operating conditions on page 4, the converter output capability is limited, depending on the input voltage:
- For VOUT nom + 0.7V ≤ VIN ≤ 5.5V the output current is 200mA
- For VOUT nom ≤ VIN ≤ VOUTnom +0.7V the output current is 100mA
If I follow the specs, the device can provide 200mA if the input voltage is 3.7V and above. For the input voltage between 3.2V and 3.7V the output current will be limited to 100mA.
TPS82740B is a very attractive option in terms of its size, and it would be great if I could use it, however the 100mA current limit is a major concern. I did some load stress testing on the eval board and the device fine at Vin 3.2V, 200mA. Can somebody from TI clarify the current limits issue?
