LM5050-1: LM5050-1

Bosco N

Prodigy 100 points

Part Number: LM5050-1

Tool/software:

we did try using LM5050-1 OR-ing for our redundant dual Power supply

1. PS-1 =24V
2. PS-2 =50V

if both the PS is connected. the o/p is always 50V even if we switch off the second LM5050-1.

Can you pl support.

Thanks

2 days ago

0 Shiven Dhir 1 day ago

TI__Mastermind 47130 points

Hi Bosco,

Please share the waveforms and schematics.

Probe VIN1, VIN2, VOUT, GATE1, GATE2

Also, are you switching OFF second LM5050-1 or the second power rail? (50V)

Regards,

Shiven Dhir

0 Bosco N 1 day ago

Prodigy 100 points

Hi Shiven,

Thanks for the reply.

the voltages are as below.

VIN1(PS1)= 24V, VIN2(PS2)=50V, VOUT=50V, GATE1=21V, GATE2=21V

The first LM5050-1 OFF pin is grounded (always ON).

we are switching off the second LM5050-1 (3.3V is fed to OFF pin).

When the second LM5050-1 is OFF. the output voltage should be 24V. But we are getting 50V

The Oring schematic was taken from the datasheet

0 Shiven Dhir 1 day ago in reply to Bosco N

TI__Mastermind 47130 points

Hi Bosco,

I think there is some misunderstanding. When the controller is turned-off, the MOSFET will turn-off but the body diode will still be active and power up the output voltage.

This is an expected behavior.

Regards,

Shiven Dhir

0 Bosco N 1 day ago in reply to Shiven Dhir

Prodigy 100 points

Hi Shiven,

Oh. So then, to get my requirement, what is the way out?

Thanks

0 Shiven Dhir 20 hours ago in reply to Bosco N

TI__Mastermind 47130 points

Hi Bosco,

Please consider LM74800

Regards,

Shiven Dhir

0 Bosco N 18 hours ago in reply to Shiven Dhir

Prodigy 100 points

Hi Shiven,

Thanks.

Will LM74800 work for our requirement? (PS1=24V 30A, PS2=50V 30A.) PS1 should always drive the load, and when PS1 is off, then PS2 should take over.

how to achieve this using LM74800? pl., suggest

Regards

0 Shiven Dhir 7 hours ago in reply to Bosco N

TI__Mastermind 47130 points

Hi Bosco,

Please check this note.

Priority Power MUX using Ideal Diodes in Automotive Zonal Modules

Regards,

Shiven Dhir

Power management

Power management forum

LM5050-1: LM5050-1