TPS24720: TPS24720 -Request for Design Support

Sujith Mohandas

Part Number: TPS24720
Other Parts Discussed in Thread: TPS25985, CSD16401Q5

I have planned to use TPS24720 Hot Swap controller in one of my project.
Below Listed my design requirement

Input Operating Voltage: VIN(NOM) :12V
Upper UVLO Threshold : 10.04V
Lower OVLO Threshold : 13.45
Maximum Load Current: IOUT(MAX ) :30A
Target Current Limit :33A
Fault Response :Latch Off
Please suggest suitable N channel MOSFET for My application ?

I have attached TPS24720 Hot Swap Design Tool calculation.
Could please verify all points and provide your feedback if any

Thanks
Sujith

over 2 years ago

0 Rakesh over 2 years ago

TI__Guru** 105001 points

Hi Sujith,

Welcome to E2E

Please consider TPS25985 eFuse for your application.

If you want to continue with TPS24720, please send the design calculator as attachment for review

Best regards,

Rakesh

+1 Sujith Mohandas over 2 years ago in reply to Rakesh

Prodigy 190 points

Hi Rakesh,

Thanks for your reply. I had explored about TPS25985. I have done some calculation for my requirement .As per design tool calculation minimum recommended number of devices to be in parallel to support Imax A is 1 nos .But there only mentioned " Number of devices selected by user (Must be more than equal to the minimum recommended one ).So i want to confirm whether my design requirement will match with one device or i need to use two device for parallel connection( stackable) ?.Could you please recheck the calculation and provide your feedback. I have attached the excel sheet.

iWave_TPS25985 Design Calculation Tool-11082022.xlsx

Regards,
Sujith

+1 Rakesh over 2 years ago in reply to Sujith Mohandas

TI__Guru** 105001 points

one tps25985 device is enough for your target specifications.

+1 Rakesh over 2 years ago in reply to Rakesh

TI__Guru** 105001 points

Hi Sujith,

We will review the design calculator and get back by early next week.

Best Regards,

Rakesh

+1 Sujith Mohandas over 2 years ago in reply to Rakesh

Prodigy 190 points

Hi Rakesh,

Could you please check the design calculator of TPS24720 ASAP.I have only short duration for this design stage. Hope your reply earlier as possible.

iWave Systems_TPS24720_Design_Calculator_REV_F.xlsx

Regards,
Sujith M

+1 Avishek Pal over 2 years ago in reply to Sujith Mohandas

TI__Mastermind 30915 points

Hi Sujith,

Please see the attached modified design calculator. MOSFET R_DSON and SOA data are modified. May we know the reason for not using TPS25985 in your design?

iWave Systems_TPS24720_Design_Calculator_REV_F__Edited.xlsx

0 Sujith Mohandas over 2 years ago in reply to Rakesh

Prodigy 190 points

Hi Rakesh,

Thanks for the reply. Could you please share the updated design calculator for tps25985 device.

Regards,
Sujith M

0 Sujith Mohandas over 2 years ago in reply to Avishek Pal

Prodigy 190 points

Hi Avishek Pal,

Thanks for sharing. One more Query regarding MOSFET selection of TPS24720 design. Can i go ahead with CSD16401Q5 MOSFET?
Should i use 2nos of MOSFET in my design ?

Regards,
Sujith M

0 Avishek Pal over 2 years ago

TI__Mastermind 30915 points

Hi Sujith,

One TPS25985 is fine for your design.

0 Sujith Mohandas over 2 years ago in reply to Sujith Mohandas

Prodigy 190 points

Hi Avishek Pal,

Im using TPS24720.so please answer above query

Regards,
Sujith M

0 Avishek Pal over 2 years ago in reply to Sujith Mohandas

TI__Mastermind 30915 points

Hi Sujith,

MOSFET steady-state maximum junction temperature is advisable to be limited to 100 C. It depends on MOSFET RDSON at 100C, MOSFET RthJA, ambient temperature, and load current. Please decide the number MOSFETs based on these information.

0 Sujith Mohandas over 2 years ago in reply to Avishek Pal

Prodigy 190 points

Hi Avishek Pal,

Ok noted. Based on the design calculator i had completed TPS24720RGTR schematics design. Attached schematics snaps for your review .Please provide if any feedback on it .

Regards,
Sujith M

0 Avishek Pal over 2 years ago in reply to Sujith Mohandas

TI__Mastermind 30915 points

Hi Sujith,

Schematic looks fine.

0 Sujith Mohandas over 2 years ago in reply to Avishek Pal

Prodigy 190 points

Hi Avishel Pal,

Thanks for your feedback. Could you recheck about Timer fault timeout setting. Initially I have set it to 9.18ms.Since mine max load current is around 30A.While doing initial power up condition,will it cause any fault trigger ?
Do i need to change Fault timeout ?

Regards,
Sujith M

+1 Avishek Pal over 2 years ago in reply to Sujith Mohandas

TI__Mastermind 30915 points

Hi Sujith,

During start-up, all the down stream loads should be turned off except the capacitors at the output of Hot Swap controller. PG signal should to turn on the down stream loads. If you follow this, fault timer duration of 9.18 ms should be fine.

0 Sujith Mohandas over 2 years ago in reply to Avishek Pal

Prodigy 190 points

Hi Avishel Pal,

Thanks for your quick response. Could you go through my power tree architecture. Here one interface directly connected to hotswap controller output. Other interface are power ON through buck regulator with hotswap power good enable.

Regards,

EMFFM-Power protection circuit.pptx

+1 Avishek Pal over 2 years ago in reply to Sujith Mohandas

TI__Mastermind 30915 points

Hi Sujith,

"SOM connector" and "E1.SSD Interface 8Nos Device" are not using Hot Swap controller PGOOD. Therefore, we need to know the startup profiles of these two loads to select the timer capacitor. If it's not known, the timer capacitor has to selected through experimentation.

+1 Sujith Mohandas over 2 years ago in reply to Avishek Pal

Prodigy 190 points

Hi Avishek Pal,

SOM connector we will be plugging SOM ,which include 12V to 5V 30A buck converter TPS53355DQPT which will be enabled by 12V input (Not Hotswap Power good control) and this 5V will be downconverter to lower voltage for peripheral power. As per E1.SSD interface specification(SFF-TA-1009) per device MAX inrush current rating is 2A.Also we can enable E1.SSD by the help of Hotswap controller Power good. Since E1.SSD interface inrush current we have in control.I have attached ppt for your reference.

Power protection circuit-25-08-2022.pptx

Regards,
Sujith M

0 Avishek Pal over 2 years ago in reply to Sujith Mohandas

TI__Mastermind 30915 points

Hi Sujith,

Please let me try to revisit the timer calculation for another time.

+1 Avishek Pal over 2 years ago in reply to Avishek Pal

TI__Mastermind 30915 points

Hi Sujith,

I would recommend you to fine tune the timer capacitor through experimentation with actual startup loads.

0 Sujith Mohandas over 2 years ago in reply to Avishek Pal

Prodigy 190 points

HI Avishek Pal,

Thanks for your replay.one more query regarding PLIM(Power limit ) selection, Currently i have selected it for 64W.Do you have any suggestion on it ?

Regards,
Sujith M

Power management

Power management forum

TPS24720: TPS24720 -Request for Design Support