PTH08T250W: DESIGN REVIEW INPUT=12V, OUTPUT=0.85V,50A WITH OUTPUT ON/OFF AND TRANSIENT=2mV/A @ 50% Load

Ganesh B

Prodigy 45 points

Part Number: PTH08T250W

Tool/software:

PTH08T250WAD_DESIGN.pdf

Request for review of schematic attached.

1) Design parameters considered are,

Input = 12V, Output = 12V, 50A,

ON/OFF of Output

Transient Deviation= 50mV @ 50% Load i.e 25A

Transient = 2mV/A,

Output Capacitor (Co) for 2mV/A transient = 3000uF

8 months ago

0 Calan Elaya 8 months ago

TI__Genius 11435 points

Hello,

A response will be posted this week.

Thanks,

Calan

0 Savith Kumar Rayakanti 8 months ago in reply to Calan Elaya

TI__Expert 5990 points

Looking at the schematic, it is fine.

1. is the output 12V or 0.85V?

2. Looking at the Rtt value and Co value provided, is it correct to assume you are using TypeC capacitors? if so 1kohm Rtt is correct.

3. as for UVLO/Inhibit pin I have already answered in a different in e2e post
https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1459854/pth08t250w-can-pth08t250w-be-used-in-air-tight-enclosure-without-airflow?tisearch=e2e-sitesearch&keymatch=PTH08T250W#

Thank you
Savith

0 Ganesh B 8 months ago in reply to Savith Kumar Rayakanti

Prodigy 45 points

1. Output is 0.85V.

2. Output Capacitors (Co) used are Polymer Electrolytic with ESR= 4mOhm. Product of (C x ESR)= (330uF x10 x 4)= 13200.

In order to achieve 2mV/A transient 3300uF (330 x 10) capacitors used. Is this correct ?

3. ok

0 Calan Elaya 8 months ago in reply to Ganesh B

TI__Genius 11435 points

Hello,

Savith will respond to this next week.

Thanks,

Calan

0 Savith Kumar Rayakanti 8 months ago in reply to Calan Elaya

TI__Expert 5990 points

Hi Ganesh

2. Output Capacitors (Co) used are Polymer Electrolytic with ESR= 4mOhm. Product of (C x ESR)= (330uF x10 x 4)= 13200.

In order to achieve 2mV/A transient 3300uF (330 x 10) capacitors used. Is this correct ?

from sections 9.1.1.4.1.1 and 9.1.1.4.2.1 RTT Resistor Selection

when Co>=3300uF, Rtt is short to ground, 0ohm. Having place holder at Rtt is enough and can be populated with 0ohm resistor

Thank you

Savith

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PTH08T250W: DESIGN REVIEW INPUT=12V, OUTPUT=0.85V,50A WITH OUTPUT ON/OFF AND TRANSIENT=2mV/A @ 50% Load