PMP4844: PMP4844

Sarumathi R

Intellectual 480 points

Part Number: PMP4844

Hi,

Our input requirement is 16VDC-48VDC and output is 24VDC/5A.

Can we able to implement the PMP4844 reference design.

If it is possible can you please provide the design details(like Resistor, Capacitor Formula and calculation)

over 4 years ago

0 John Griffin1 over 4 years ago

TI__Mastermind 34465 points

Hi,

The PMP4844 has an input voltage range of 18V to 54V and an output of 24V 5A.
It also has a UVLO set point of 17.4V.
This means you will need to change the UVLO threshold to about 15V.
If you change R10 from 3.92k to 4.64k then you should be able to use the PMP4844 for your requirements.
The UVLO will then be set at 14.9V

4721.G095024LF r 0.pdf

Also I am attaching the transformer drawing.
You can see that the primary to secondary turns ratio is 2:1 .
The UCC2897A has a maximum duty cycle of 0.7
This means with 16V in the maximum possible output voltage is 16*2*0.7 = 22.4V

So you will need to use a higher turns ratio.
If you use a 2.25:1 turns ratio then the maximum duty cycle required will be about 0.66.

These are the two changes that I think you will require in order to operate at a lower input voltage.

Regards

John