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TPS259827LEVM: About Thermal shutdown limit time margin

Part Number: TPS259827LEVM

Hi team,

Our customer evaluated this EVM in below condition.

Vin : 19V

Load : capacitance load 1400uF only (They assume Fly back circuit total input cap)

Iout: max 3A

setting : 

J9   = 5-6 (Programmable Fault Timer = 20ms)
J10 = 3-4 (Programmable Current Limit = 3A)
J6   = 1-2 (Current Monitor Scaling = 0.13V/A)
J11 = Open (Retry delay setting = 200us)
J4   = 3-4 (NRETRY = 16times)
J12 = 1-2 or 3-4 (Output Slew Rate Control = 1.5V/ms or 0.5V/ms)

And they observed thermal shutdown asserted when start up by inrush current. So they are selecting appropriate Tdvdt and Cdvdt value now.

When the Cdvdt is over 0.04uF, thermal shutdown was not asserted and start up correctly the power dissipation was under 1.33W from equation 21, 22.

We reference figure 53 in datasheet, but figure 53 shows only over 3W.

In datasheet, it is said that "It is safe to have 30% margin to allow for variation of system parameters such as load, component tolerance, and input voltage."

Do you have the data under 3W? And I would like to know your opinion on the operation at the around 1W power dissipation.

If you recommend other device which has more power capacity, let me introduce.

best regards,

teritama