Hi team,
TPS7A1650. VIN and EN are connected together, PG is connect to GND.
We find when VIN rise to 3-5V, which will result a output <5V. During these period, the Iq is 20-30uA. When VIN rise to a larger voltage, like 12V, Iq will be back to 5uA. Could you kindly help evaluate why the Iq will be larger when VIN is <5V?
I guess the PG FET inside driver may cause some current consumption. Not sure if it is correct. Any problem, feel free to let me know.
Regards
Michael
Hi Michael,
Since you are using the fixed 5 V output version, the LDO is still operating in dropout until VIN is large enough for the device to regulate the output. In dropout, the internal control loop drives the pass transistor as hard as possible which may require additional bias current. The typical 5 uA ground current applies when the LDO is properly regulating the output. This requires:
Vin > Vout + Vdo
Where Vdo is the dropout voltage at your application's required output current.
The current used to drive the PG FET is included in the typical ground current specification, and negligible current is consumed by the PG FET since the drain and source are both grounded.
Thanks,
Gerard
