UA723: Current foldback circuit for positive floating regulator.

Bala Thirumavalavan

Prodigy 110 points

Part Number: UA723

Hi,

This is from the data sheet of UA723. Can this equations be applied to Figure7?

Thanks,

Bala T.

over 4 years ago

0 Stephen Ziel over 4 years ago

TI__Mastermind 35105 points

Hi Bala,

The equations apply to the circuit in figure 6.
You would need to take R3 and R4 from figure 6 and add them to figure 7 to obtain current foldback using these equations.

Thanks,

- Stephen

0 Bala Thirumavalavan over 4 years ago in reply to Stephen Ziel

Prodigy 110 points

Hi Stephen,

Thank you so much for you quick response again!

I will try this method to achieve 45 V output with current foldback feature.

Best Regards,

Bala T.

0 Bala Thirumavalavan over 4 years ago in reply to Stephen Ziel

Prodigy 110 points

Hi Stephen,

Could you tell me how to calculate R3 and R4 for foldback current limiting (figure 6)?

Thanks,

0 Stephen Ziel over 4 years ago in reply to Bala Thirumavalavan

TI__Mastermind 35105 points

Hi Bala,

I have been away from the office. Do you still need assistance with this?
If you know your knee current, Ios value and output voltage, then you have 2 equations and 3 unknowns (Rsch, R3, R4).

The knee current, Ios value and output voltage should be understood as initial requirements before designing the resistors.

You have some flexibility here with 3 unknowns and 2 equations so set one of the unknowns and use the equations to choose the other two values.

Thanks,

- Stephen

0 Bala Thirumavalavan over 4 years ago in reply to Stephen Ziel

Prodigy 110 points

Hi Stephen,

I am glad to hear from you. Your detail explanation was very helpful -thanks.

Best Regards,

Bala T.

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UA723: Current foldback circuit for positive floating regulator.