TL783: Is there a problem of TL783 two series configuration?

Bob Lee62837

Part Number: TL783
Other Parts Discussed in Thread: TVS3300

Dear Support member.

My customer used TL783.

I would like to configure it in two series for the purpose of distributing the voltage at the time of rush.
Is there a problem with how to use like this?

I attached about question file.
Could you check attached file?

Best regard.

Bob Lee.

TL783_Question_180329.pdf

over 7 years ago

0 kai klaas69 over 7 years ago

Guru 140200 points

Hi Bob,

why do you want to do this?

Kai

0 Ryan Eslinger over 7 years ago

TI__Guru 55940 points

Hi Bob,

This is a valid way to help spread the voltage drop and therefore dissipated power. Please note that since neither Vref nor the Resistor for each TL783 will be exactly the same, the current through the LED will be set by the lower resistor/regulator combination.

Very Respectfully,
Ryan

0 Bob Lee62837 over 7 years ago in reply to Ryan Eslinger

Mastermind 7230 points

Dear Ryan Eslinger,

Thank you very much for reply.

In the present circumstances,
There is inrush voltage problem.

In the application, input supply become 220V AC.
My customer use diode bridge, convert to DC voltgae.

There are times when the inrush voltage is 180V DC.

Can I distribute spread the inrush voltage in this two series way?

Best regard.
Bob Lee.

0 kai klaas69 over 7 years ago in reply to Bob Lee62837

Guru 140200 points

Hi Bob,

220V AC mains voltage? You know, that mains voltage comes from hell and can have huge surges and voltage spikes of thousands of volts?

Kai

0 Bob Lee62837 over 7 years ago in reply to kai klaas69

Mastermind 7230 points

Dear Kai,

I'm Sorry.
I lacked of information.

TVS3300 is connected in parallel between TL783 INPUT terminal and ADJ terminal as a surge countermeasure.

It will be the same question,

Q1
Can I distribute spread the inrush voltage in this two TL783 series way?

Best regard.
Bob Lee.

0 Ryan Eslinger over 7 years ago in reply to Bob Lee62837

TI__Guru 55940 points

Hi Bob,

Yes since TL783 can have a Vin to Vout delta of 125 V and your application would have Vout equal to Vref, you are within the device operating conditions by stacking two in series.

Very Respectfully,
Ryan

Power management

Power management forum

TL783: Is there a problem of TL783 two series configuration?