TL432: IS IT NEED LOAD CAPACITANCE FOR TL432?

HYUNCHUL LIM

Part Number: TL432
Other Parts Discussed in Thread: TLVH432

Hello.

I hope you understand my lack of English.

We are using TL432 for OCP circuits.

As shown in the picture below, there is an oscillation phenomenon for some TL432 samples with the corresponding point voltage, and the oscillation phenomenon is removed when parts are replaced.

In this case, I understand that connecting LOAD CAPACITOR will improve the problem, is it right? Then, how much capacity do we need?

And do we have to connect to the load capacitor?

thank you.

11 months ago

0 Walter Zollinger 11 months ago

TI__Expert 6660 points

Hello,

This graph from the data sheet shows the stability regions of load capacitance and input current. Please use a load capacitance greater than 10uF or smaller than 0.01uF.

I would also suggest to lower the value of R358 to a value smaller than 20k Ohms. The TL432 needs a minimum current of 1mA.

Best,

Walter

0 kim do yoon 11 months ago in reply to Walter Zollinger

Prodigy 40 points

Hi Walter

thanks your answer

Is it a problem that two 24V (30kohm + 240kohm) / 5V (4.7kohm) voltage sources are connected to the anode of TL432?

Best,

0 Walter Zollinger 11 months ago in reply to kim do yoon

TI__Expert 6660 points

Hello,

Can you clarify the function of the schematic? Is the 5V powering the TL432 through R395 and the TL432 creates an offset voltage for the op-amp? A lower resistance value should be used for R395. The output of the TL432 should not be 1.23V. Is a different part like TLVH432 being used?

Best,

Walter

0 kim do yoon 11 months ago in reply to Walter Zollinger

Prodigy 40 points

Hi Walter

It was used as TLVH432.
Apply the offset voltage of the opamp with a 5 volt power supply.
The reason why 5V and 24V are used at the same time is because of the sequence.
After 5 volts is applied, 24 volts will be output.
The defective phenomenon is the occurrence of oscillations in the anode voltage waveform.
As for the normal waveform, a 1.24V oscillation-free waveform is measured.

Best

0 Walter Zollinger 11 months ago in reply to kim do yoon

TI__Expert 6660 points

Hello,

Have you tried adding a load capacitor 1uF or larger to the TLVH432 output?

Best,

Walter

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TL432: IS IT NEED LOAD CAPACITANCE FOR TL432?