LM5067: LM5067

Jainendra Bahadur

Part Number: LM5067
Other Parts Discussed in Thread: CSD19532Q5B, TPS23523, CSD19536KTT, LM5064

Hello,

We are using Hot swap controller part#LM5067 in one of our design.

The calculated current passing though mosfet will be 28 amps @ -ve 48V.

Kindly suggest the mosfet and other discrete parts also.

Regards,

Jainendra Bahadur

over 7 years ago

0 Rakesh over 7 years ago

TI__Guru** 105361 points

Hi Jainendra,

Welcome to E2E!
Can you share more information about your project.

Please use the design calculator to check the design feasibility www.ti.com/.../toolssoftware . Start with MOSFET CSD19532Q5B or PSMN4R8-100BSE.

Best Regards,
Rakesh

0 Jainendra Bahadur over 7 years ago

Intellectual 490 points

Hello Rakesh,

Thanks for the reply.

We want to design the Power supply module for the chassis. Input voltage is -ve 48VDC and the total power to be delivered is 2X1344=2688 watts.

We will use two hotswap controller IC for one module. one HS for fan's power supply and other for Line+Controller card's power supply.

I have attached the design calculator sheet for your reference. The mosfet which we have selected is partPSMN4R8-100BSE. But the sheet shows some red blocks.

Kindly suggest accordingly.

Regards,

Jainendra

LM5067_Design_Calculator_BAYTOP.xlsx

0 Rakesh over 7 years ago in reply to Jainendra Bahadur

TI__Guru** 105361 points

Hi Jainendra,

Thanks for the details about your system.
Forgot to inform you. We have new device TPS23523 which offers better current limit accuracy and fast short circuit response over LM5067 device. Can you check and confirm. If you are interested to switch to the new device, please send filled up design sheet of TPS23523 device for review.

Best Regards,
Rakesh

0 Jainendra Bahadur over 7 years ago in reply to Jainendra Bahadur

Intellectual 490 points

Hello Rakesh,

We require two hot swap controller because one of the supply goes to FAN controller card which can introduce noise.
The LM5067 has lesser cost than TPS23523.

So we would like to use the LM5067 device.

Kindly provide the design feasibility of LM5067 w.r.t. our requirement .

Thanks,
Jainendra

0 Rakesh over 7 years ago in reply to Jainendra Bahadur

TI__Guru** 105361 points

Hi Jainendra,

Please refer the attached design calculator .

We need to use 3 FETs in parallel to meet SOA margin. The MOSFET on-resistance is extrapolated and taken as 10mOhm at TjDC of 105C. Let me know if you have any questions.

7851.LM5067_Design_Calculator_BAYTOP.xlsx

Best Regards,

Rakesh

0 Jainendra Bahadur over 7 years ago in reply to Rakesh

Intellectual 490 points

Hello Rakesh,

Thanks for the support.

Using 3 FETs with IC LM5067 doesn't look cost effective and performance wise better solution rather if we can use device TPS23523 suggested by you with only single mosfet.

I have attached the design calculator sheet for your reference.

Kindly provide the feedback.

Regards,

Jainendra

TPS2352X_Excel_Tool_Baytop.xlsx

0 Rakesh over 7 years ago in reply to Jainendra Bahadur

TI__Guru** 105361 points

Hi Jainendra,

You will need more than single MOSFET even with TPS23523 device to manage Ron loss at 28A load current and for better SOA margin. The advantage with TPS23523 device is you can use different type of MOSFETs for Q1 and Q2 to optimize the system cost and performance.
Please consider CSD19536KTT for Q1 and CSD19532Q5B for Q2.

Please get in touch with any TI-sales person to get TPS23523 evaluation board. The control approach is different and would be good to explore before going into design.

Best Regards,
Rakesh

0 Jainendra Bahadur over 7 years ago in reply to Rakesh

Intellectual 490 points

Hello Rakesh,

Thanks for the support.

We would use the device TPS23523 with the specified CSD19536KTT for Q1 and CSD19532Q5B for Q2. mosfets.

Kindly fill the design calculation sheet for our reference.

PFA.

Regards,

Jainendra1055.TPS2352X_Excel_Tool_Baytop.xlsx

0 Rakesh over 7 years ago in reply to Jainendra Bahadur

TI__Guru** 105361 points

Hi Jainendra,

Please let me know where you faced challenge while filling the design sheet.

Best Regards,
Rakesh

0 Jainendra Bahadur over 7 years ago in reply to Rakesh

Intellectual 490 points

Hello Rakesh,

I have filled the excel sheet but need clarification on some points mentioned below :

	ROW number in the excel sheet	Heading	Remarks	TI response
1	E16	output capacitance	For inrush current 0.4A the capacitance is calculated, Is it ok?
2	E23	Selected Rsns	Can we select any value near to calculated Rsns (Row E22)
3	E30	Q1 Cgs (Gate to source capacitance)	how to decide the value
4	E41	Required to pass ATIS 06003.2013 "Fig 1" or other brown out test?	The brown out should be used or not ??
5	E50	Target Ilim, switch	How to decide
6	E59 to E66	Current handling	How to put data
7	E82	Should selected values be nearly same as Computed values ?
8	Next sheet “brownout “	Some values are missing	Should we ignore the things if brown out not use “

The input voltage is -ve 48VDC at 28 Amps. Output is also same.

Kindly review all the values fill in the sheet.

Regards,

Jainendra

TPS2352X_Excel_Tool_Baytop_edit.xlsx

0 Rakesh over 7 years ago in reply to Jainendra Bahadur

TI__Guru** 105361 points

Hi Jainendra,

Please refer the last column for the response.

Best Regards,

Rakesh

0 Jainendra Bahadur over 7 years ago in reply to Rakesh

Intellectual 490 points

Hello Rakesh,

Thanks for the response.

We would like to control the UVEN pin with a controlling device. To make the hostswap controller OFF the voltage at UVEN pjn should be lower than 1.015Vdc as per the datasheet (correct me if wrong).
By default TPS23523 should be off.
Kindly suggest the suitable Mosfet and the components for our requirement.

Regards,
Jainendra

0 Rakesh over 7 years ago in reply to Jainendra Bahadur

TI__Guru** 105361 points

Hi Jainendra,

You should set below 0.985V at UVEN pin to make sure that the device is OFF.

As shown below for LM5064, an external FET at UVEN pin provides you controllability. Any 60V rated N-FET would be enough.

Best Regards,

Rakesh

0 Jainendra Bahadur over 7 years ago in reply to Rakesh

Intellectual 490 points

Hello Rakesh,

We have made the schematic using the device TPS23523.

Here we have used UVEN pin for an on/off functionality also and a mosfet part#NDS7002A is used for

the said purpose.

I have attached the design calculator in which used values are different than the calculated one.

Kindly review the schematic and provide the feedback.

Regards,

Jainendra

BAYTOP_tps23523_edit.pdf 5684.TPS2352X_Excel_Tool_Baytop_edit.xlsx

0 Rakesh over 7 years ago in reply to Jainendra Bahadur

TI__Guru** 105361 points

Hi Jainendra,

Looks fine.
One clarification:- to allow 35.4A at minimum input voltage of 38V, the target current limit should be set to 35A.
Any reason to use 40mV for sense voltage instead of 25mV for lower loss?

Best Regards,
Rakesh

0 Jainendra Bahadur over 7 years ago in reply to Rakesh

Intellectual 490 points

Hello Rakesh,

The current consumption of the units connected via hot swap would not be more than 28 amps, so we have entered 28amps @ 48V but the calculated load current comes 35.4 amps.

We have changed the value to 25mV. Please find the attached excel sheet.

Please verify the schematic as well as the selected components in the excel sheet.

Regards,

Jainendra

8713.TPS2352X_Excel_Tool_Baytop_edit.xlsx

0 Rakesh over 7 years ago in reply to Jainendra Bahadur

TI__Guru** 105361 points

Hi Jainendra,

Ok.
Please use 0.75mOhm for Rsns, rest of the circuit is fine.

Best Regards,
Rakesh

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LM5067: LM5067