REF34-Q1: Thermal hysteresis of ENABLE pin threshold

Yuta Kurimoto

Expert 8260 points

Part Number: REF34-Q1

Hello Team,

I'm Yuta Kurimoto TIJ FAE.

I got some question from customer about the hysteresis of Enable pin threshold. The part number is REF3450QDBVRQ1.

Q. How much thermal hysteresis the ENABLE pin threshold has? Typical value is OK.

Thanks,

Yuta Kurimoto

over 5 years ago

0 Ethan T over 5 years ago

TI__Expert 3835 points

Hi Kurimoto-san,

Unfortunately we do not specify the enable threshold pin this way . The REF34-Q1 datasheet provides the enable pin voltage specification (VEN) at the bottom of table 7.5. It provides the maximum value that is required for an EN = 0 and minimum value for EN = 1 across temperature. If the customer provides within these max/min voltage, then they can guarantee EN = 0 or EN = 1.

The difference between the value is 1.1V. Which could be one way to estimate the thermal hysteresis of the pin as well.

Hope this helps,
Ethan

0 Yuta Kurimoto over 5 years ago in reply to Ethan T

TI__Expert 8260 points

Hello Ethan,

Thanks for your answer. Let me confirm one thing.

Do you mean the VEN value is guaranteed across temperature(-40C to 125C)?

I though it is guaranteed only at Ta=25C...

Thanks,

Yuta Kurimoto

0 Ethan T over 5 years ago in reply to Yuta Kurimoto

TI__Expert 3835 points

Hi Kurimoto-san,

Our min and maximum values are taken across temperature. Our typical values are taken at Ta = 25C.

Thanks,

Ethan

0 Yuta Kurimoto over 5 years ago in reply to Ethan T

TI__Expert 8260 points

Hello Ethan,

Thanks for your answer. Let me confirm one thing.

Below is my understanding, Is it correct?

In customer's system, the EN voltage may be chatter so they want this device to have hysteresis.

Is it possible for you to measure "OUT(Y-axis) vs VEN(X-axis)" curve in order to know the hysteresis value?

Thanks,

Yuta Kurimoto

0 Ethan T over 5 years ago in reply to Yuta Kurimoto

TI__Expert 3835 points

Hi Kurimoto-san,

I will be out for US holiday for the next few days, but will get you this data sometime before the end of next week. Thanks for your patience.

Thanks,
Ethan

0 Ethan T over 5 years ago in reply to Ethan T

TI__Expert 3835 points

Hi Kurimoto-san,

I have sent you an email regarding the results, feel free to give me your feedback here or by email.

Thanks,
Ethan

0 Yuta Kurimoto over 5 years ago in reply to Ethan T

TI__Expert 8260 points

Hello Ethan,

Thanks. I got the data.

Yuta Kurimoto

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REF34-Q1: Thermal hysteresis of ENABLE pin threshold