TPS561243: Request for Detailed EN Pin Zener Diode Characteristics – TPS561243

BEROSE ABDUL KADAR A

Part Number: TPS561243

Dear TI Support Team,

I am currently working on a design using the TPS561243 buck converter and need detailed information about the internal Zener diode connected to the Enable (EN) pin.

Specifically, I would like to know: - The exact Zener voltage and tolerance. - Maximum allowable current through the Zener diode. - Power dissipation limits. - Dynamic resistance or any relevant electrical characteristics under breakdown conditions.

Our understanding is specified enable pull down current 1uA will vary if VEN = 3 to 5V is the right understanding ?

This information will help ensure proper resistor sizing and reliable operation in my application. Thank you for your assistance.

24 days ago

0 Haseen Reddy Siripi Reddy 23 days ago

TI__Expert 8060 points

Hi Berose,

We will check ad get back on this.

Regards,

Haseen.

0 Manish Gautam 23 days ago in reply to Haseen Reddy Siripi Reddy

TI__Expert 5100 points

Hi Berose,

We are in touch with Design guys, once they will respond after that we will get back to you.

Regards,

Manish

0 Manish Gautam 17 days ago in reply to Manish Gautam

TI__Expert 5100 points

Hi Berose,

In datasheet, it is clearly mentioned about the pullup resistor value (100k ohm).

Sorry, we can't share the internal details of zener diode.

Regards,

Manish

0 BEROSE ABDUL KADAR A 17 days ago in reply to Manish Gautam

Prodigy 10 points

Thanks for the response,

If the enable pin voltage (V_EN) exceeds 1.5V, the pull-down current (I_EN) is not fixed at 1 µA — it becomes variable?

For example, when V_EN = 4.5V, the internal Zener diode attempts to clamp the voltage to around 2V, resulting in a pull-down current of approximately 167 µA.

This behaviour confirms that I_EN increases with higher V_EN, due to the internal Zener regulation is the understanding correct?

0 Manish Gautam 16 days ago in reply to BEROSE ABDUL KADAR A

TI__Expert 5100 points

Hi Berose,

If EN pin value will be 1.5V then Zener will not go into the breakdown and yes, that pull down current will not be fixed.

I_EN increases with increase in V_EN voltage.

Regards,

Manish

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TPS561243: Request for Detailed EN Pin Zener Diode Characteristics – TPS561243