TPS548D22: RSP and RSN Feedback Resistors Consult

Stanley Dai

Part Number: TPS548D22

Hi Team,

Customer is asking do we have additional requirements for RSP and RSN feedback resistors besides less than 100kohm? Pls help us here. Thanks.

Best,

Stanley

over 3 years ago

+1 Alec Biesterfeld over 3 years ago

TI__Expert 5310 points

Hi Stanley,

The reason why we recommend resistor divider values below 100kohm has to with the leakage current that flows into the feedback pin. If the feedback resistors are too large, the current that can flow through the feedback resistor network may be limited such that a larger percentage of the current flowing from the output through the top feedback resistor leaks into the feedback pin (RSP in the case of the TPS548D22) and the feedback voltage begins to droop as the divider resistors increase.

The following article explains this in greater detail:

/cfs-file/__key/communityserver-discussions-components-files/196/Design-considerations-for-a-resistive-feedback-divider-in-a-DCDC-converter.pdf

Regards,

Alec Biesterfeld

Power management

Power management forum

TPS548D22: RSP and RSN Feedback Resistors Consult