TPS73101 unstable at 5.2 to 5@100mA

Aaron Jones

Intellectual 760 points

Other Parts Discussed in Thread: TPS731

Hi All,

I'm hearing about some stability issues with the TPS73101.

The system set up:

Input = 5.2
Output = 5V
Current = < 100mA
"Had to put a 1Ohm resistor in series to stabilize the device to achieve the desired 45 deg phase margin"

They do not want to have to use the resistor to maintain stability. Is this the expected behavior?

Regards,

Aaron

over 9 years ago

0 Ryan Eslinger over 9 years ago

TI__Guru 55940 points

Hi Aaron,

Could you provide a scope shot and schematic for us to be able to help debug?

Please note that while TPS731 is stable without an output capacitor, the addition of an output capacitor and a feedforward capacitor will improve transient response.

Very Respectfully,
Ryan

0 Ryan Eslinger over 9 years ago in reply to Ryan Eslinger

TI__Guru 55940 points

Hi Aaron,

To be clear for the scope shot, please include Vin (DC), Iload (DC), and Vout (AC).

Very Respectfully,
Ryan

Power management

Power management forum

TPS73101 unstable at 5.2 to 5@100mA