External pull up resistor for EN pin - UC27444-Q1

Prahaladh S

Hi,

We're using UC27444-Q1 for one of our applications. As per the datasheet, the EN pins are pulled up to VDD using 100k ohms. In our application, we're using certain circuitry to turn OFF the UC27444-Q1 in case of over current fault. In this case, an external pull up to EN (eg: 10k) would be an overdo ??

Thanks in advance.

Best Regards,

Prahaladh S

over 1 year ago

+1 Rubas Khalid over 1 year ago

TI__Expert 8791 points

Hi Prahaladh,

It is entirely dependent on if your power supply can handle the increased current load, where I = VDD / R_EN when EN is pulled low. For example, if you do not use an external pull-up resistor and only rely on the 100k internal resistor, you will use 120uA when EN goes low. If you use an external 10k pull-up resistor, then you will use 1.2mA.

Thanks,
Rubas

0 Prahaladh S over 1 year ago in reply to Rubas Khalid

Prodigy 100 points

Thank you for your response Rubas...

Regards,

Prahaladh S

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External pull up resistor for EN pin - UC27444-Q1