LM5165-Q1: R in series with COUT mandatory in COT mode?

Basil

Intellectual 1620 points

Part Number: LM5165-Q1

Team,

is the resistor in series to COUT mandatory in COT operation?

As per the EVM guide snvu511 (http://www.ti.com/lit/ug/snvu511/snvu511.pdf

over 7 years ago

0 Basil over 7 years ago

TI__Intellectual 1620 points

Sorry, incomplete message above. Please find correction below:

Team,

is the resistor in series to COUT mandatory in COT operation?

As per the EVM guide snvu511 (www.ti.com/.../snvu511.pdf), Fig. 28,
we have R11 = 1.5Ohm in series with COUT.

Are there any issues to be expected if I gp with R11 = 0Ohm?

Thanks and regards,
B

0 Ambreesh Tripathi over 7 years ago in reply to Basil

TI__Expert 6860 points

Typical COT hysteretic controllers need a significant amount of output capacitor ESR to maintain a minimum
amount of ripple at the FB pin in order to switch properly and maintain efficient regulation. You may choose electrolytic cpacitor for you application or add ripple injection circuitry as mentioned in this app note .

www.ti.com/.../snva166a.pdf

Ambreesh

Power management

Power management forum

LM5165-Q1: R in series with COUT mandatory in COT mode?