TLV62585: Maximum Load Capacitance

Eben Louw

Part Number: TLV62585

Hello,

In the datasheet the recommended output capacitance for the TLV62585 dc/dc converter with a 1uH inductor is 47uF.

I want to use this part with a 5V input and 3.8V output, to power a GSM module. The GSM module has a capacitance on it's input of ( 470uF x 2 ). This capacitance will essentially sit on the output of the TLV62585 part.....will this pose as a problem ? If this part is not suitable, please advise.

Regards,

Eben

over 4 years ago

0 Excel Regidor over 4 years ago

TI__Mastermind 30871 points

Hi Eben,

Are you aware what type of capacitor is the 470uF? Ceramic or electrolytic? And how far is the TLV62585 to the GSM module?

Best regards,

Eben

0 Eben Louw over 4 years ago in reply to Excel Regidor

Prodigy 80 points

Hello,

Thanks for the reply.

There are 2 x 470uF capacitors in parallel to handle the GSM peak currents. These caps are mounted very close to the GSM module's power input pins. They are Polymer Electrolytic Capacitors, low esr,... Kemet Part# T520D477K006ATE030, datasheet here : https://content.kemet.com/datasheets/KEM_T2076_T52X-530.pdf

The distance from TLV62585 to GSM is 30mm, so very close proximity.

Regards,

Eben

0 Excel Regidor over 4 years ago in reply to Eben Louw

TI__Mastermind 30871 points

Hi Eben,

I did the bode plot simulation based on below PCB trace parameters and the loop control looks stable with phase margin of 78.96 deg.

For further verification, I recommend to make an actual bode plot measurement on the application then check the phase margin which should be => 45 deg.

Best regards,

Excel

0 Excel Regidor over 4 years ago in reply to Excel Regidor

TI__Mastermind 30871 points

Hi Eben,

If you don't have further queries, then I will close this thread.

Thank you.

Best regards,

Excel

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TLV62585: Maximum Load Capacitance