TL431A: Stability Boundary Conditions on the datasheet P16

Hirotaka Matsumoto

Part Number: TL431A

Hi all

Would you mind if we ask TL431A?

Is "Figure16. Stability Boundary Conditions" on the datasheet P16 with ceramic cap or aluminum cap?
We would like to know the effect of ESR.
Does ESR(cap type) affect stablity?

Kind regards,

Hirotaka Matsumoto

over 7 years ago

0 kai klaas69 over 7 years ago

Guru 140200 points

Hi Hirotaka,

you should read the application note SLVA482. You will find the link in section 10.2.2.2.3 of datasheet.

Kai

0 Hirotaka Matsumoto over 7 years ago in reply to kai klaas69

Guru 27585 points

Kai san

Thank you so much for your reply!

Just in case, we would like to confirm one point.

On the document SLVA482 Figure.5 to Figure.8, these figures show the minimum recommended series resistance to add for desired output capacitance.

For example "Figure 5. ESRs @ Vka=2.5V", in case of "condtion = 2.5V 3.2mA" and CL=0.01uF, ESR requires more than 30ohm.
Is our recognition correct?

Kind regards,

Hirotaka Matsumoto

0 kai klaas69 over 7 years ago in reply to Hirotaka Matsumoto

Guru 140200 points

Hi Hirotaka,

yes, that's correct.

Kai

0 Marcoo Z over 7 years ago in reply to kai klaas69

TI__Mastermind 19580 points

Hi Hirotaka,

I agree with Kai's answers. The TL431 is not very stable for values between 10nF and 4 uF. So the addition of a ESR resistor is needed to make this work. We do have devices in our portfolio, such as the LM4041-N which are stable for any load capacitor.

-Marcoo Z

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TL431A: Stability Boundary Conditions on the datasheet P16