Inquiry regarding TL783 required time to be stabled

Atsushi Okui

Genius 4015 points

Other Parts Discussed in Thread: TL783, LM317

Hello, all

Now we have one inquiry regarding TL783 required time to be stabled from our customer.

Please refer to the item below, and feedback us with your comment.

Now we are going to use this device for generating constant current.

Here is the detailed condition for using this device:

Vin = 60V and Iout = 80mA

On this condition, we would like to know how long should it be considered from powering up this device to make the output current stabled.

We thank you in advance for your information.

Best regards,

over 11 years ago

0 Ron Michallick over 11 years ago

TI__Guru**** 166116 points

Atsushi-san.

I don't know the answer. I can run some lab test this week to see.

0 Atsushi Okui over 11 years ago in reply to Ron Michallick

Genius 4015 points

Ronald-san,

Thank you for your prompt reply.

Please send your test result as soon as you could get any test results.

We thank you once again for your information.

Best regards,

0 Ron Michallick over 11 years ago in reply to Atsushi Okui

TI__Guru**** 166116 points

Atsushi,

Do you have any information about the output load impedance?
At minimum a need to know the range of output voltage compliance needed to make sure there is enough headroom for the TL783.

0 Atsushi Okui over 11 years ago in reply to Ron Michallick

Genius 4015 points

Ronald-san,

Thank you for your taking in consideration regarding TL783 inquiry from our customer.

At last, we could get detailed information of output load impedance.

Please refer to the items below;

The object for supplying constant current is LEDs which is connected 83 pieces in parallel.

On supplying into LEDs, we also use LM317 with TL783 in parallel.

Therefore, the output impedance of TL783 is equal to Vf characteristic on the LEDs.

We thank you once again for your information.

Best regards,

0 Ron Michallick over 11 years ago in reply to Atsushi Okui

TI__Guru**** 166116 points

Atsushi-san,

I have DC sweeps with TL783 and 15 ohm resistor (84mA).
I also have AC signals for 16V and 60V fast rise time input voltage. Output was 50 ohm load.
Upon fast power in, the TL783 had a substantial shoot through current.

My input pulses had very high slew rate. 9V/nS for 60V input step ans 2.3V/nS for 16V input step.
Please see data figure 13 and text at bottom of page 9 to see warnings for voltage slew rate.

TL783 + 15ohm Current Source.zip

0 Atsushi Okui over 11 years ago in reply to Ron Michallick

Genius 4015 points

Ronald-san,

Thank you for your sending your test result on TL783 constant current measurement.

Please let us see your schematic of test board that you measured for this test.

We thank you once again for your information.

Best regards,

0 Ron Michallick over 11 years ago in reply to Atsushi Okui

TI__Guru**** 166116 points

Atsushi-san,

Here is the test setup schematic.

Power management

Power management forum

Inquiry regarding TL783 required time to be stabled