TLV700: Regarding max capacitive load of TLV70030DCKR.

Jagdish Karamchandani

Part Number: TLV700

Hello Support,

We intend to use TLV70030 in one of application where device needs LDO supplies with added capacitors in its VCC as shown in attached image. VOUT=3.0V, VIN=3.3V, load current varies from 1mA to 50mA. Could you please advise,

* If TLV70030 be stable with this capacitive on startup, normal operation.

* Do we see any degradation of other parameters apart from stability issues.

Awaiting your response.

Regards,

jagdish

over 2 years ago

0 Andres Sagredo over 2 years ago

TI__Expert 6660 points

Hi Jagdish,

The overall capacitance here seems fairly reasonable, however if you see any issues you can add another 100nF capacitor to decrease the ESR.

You could also increase input capacitance if there are any issues on start-up.

The output capacitance shouldn't degrade other parameters and it is stable with an effective output capacitance greater than 100nF.

Regards,

Andres

0 Jagdish Karamchandani over 2 years ago in reply to Andres Sagredo

Expert 1420 points

Hello Andres,

Sorry for delayed response. If we add 100nF at output to decrease ESR can't it generate startup issues due to low ESR? Please advise. Idea here was to get advise as to how much capacitance TLV70030 can take. Are there any specific figures which should be respected?

Regards,

jagdish

0 Edgar Acosta1 over 2 years ago in reply to Jagdish Karamchandani

TI__Genius 12675 points

Hi Jagdish,

Andres is currently OoO.

As stated, the device only requires 0.1uF minimum capacitance for stability. The image shared shows more than enough capacitance on the output. What Andres was referring in regards ESR is that the maximum ESR for this device should not exceed 200mOhms in order to maintain stability. Decreasing the ESR will not interfere with the startup of the device.

As with the majority of our LDOs, increasing Cout will increase the response time of the LDO when seeing a transient, what this means is that it will take slightly longer times to recover from a transient event, this with the benefit of reducing the undershoot and overshoot.

How close are these capacitors to the LDO? Also, what is being used on the input?

Best,

Edgar Acosta

0 Jagdish Karamchandani over 2 years ago in reply to Edgar Acosta1

Expert 1420 points

Hello Edgar,

Thanks for clarifications regarding startup concerns. Output capacitors will be <=10mm to LDO & input capacitors to LDO will be 4.7uF/25V+0.1uF/50V.

Regards,

jagdish

0 Edgar Acosta1 over 2 years ago in reply to Jagdish Karamchandani

TI__Genius 12675 points

Hi Jagdish,

With a Vout of 3.3V and the given capacitor ratings, you should still meet the capacitance requirements.

Best,

Edgar Acosta

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TLV700: Regarding max capacitive load of TLV70030DCKR.