TPS53319: About EN pin

Tsukui Yusuke

Guru 21930 points

Part Number: TPS53319

Hi,

Customer is trying to control sequence by controlling EN with CPLD

Customers connect the EN pins of multiple devices to one signal source.
In the background, customers are looking into pull-up resistor constraints.

１．Does TPS53319 have a Zener diode and pull-down resistor inside the EN pin?
　　Could you tell me the Zener voltage and pull-down resistor value?

２．When dividing the control voltage of the EN pin externally,
　　Is there a restriction on the voltage dividing resistor value?
　　Customer is using a pull-up voltage of 12V. This voltage is divided to 3V.

３．Please advise on the precautions when sharing EN signals with multiple devices.

Regards,
Yusuke

over 5 years ago

0 Peter James Miller over 5 years ago

TI__Guru 56795 points

Tsukui Yusuke

The TPS53319 converter's enable pin definition is in the datasheet:

There is an internal current source of 1uA that will need to be accounted for by the shared circuitry. There is an ESD clamping circuit on the EN pin that can clamp the EN voltage if it exceeds a device threshold above the Vreg voltage. There is no internal pull-down resistor.

0 David_Daniels over 5 years ago

TI__Mastermind 23695 points

The 5-V LDO is not controlled by the EN pin. The LDO starts-up any time VDD rises to approximately 2 V.

Enable pin voltage should not be higher than VREG by 0.8 V.

Typical turn-on enable threshold voltage is 1.3 V. Typical enable turn-off threshold voltage is 1.0 V.

The absolute maximum voltage rating is 7V on the enable pin.

I will ask development team regarding a diode on enable pin.

0 Tsukui Yusuke over 5 years ago in reply to David_Daniels

Guru 21930 points

Hi David-san, Peter-san,

Thank you for your kind support.
I will report your information to the customer.

I will continue to look forward to your contact.
"I will ask development team regarding a diode on enable pin."

Best regards,
Yusuke

0 Peter James Miller over 5 years ago in reply to Tsukui Yusuke

TI__Guru 56795 points

You are welcome.

0 David_Daniels over 5 years ago in reply to Tsukui Yusuke

TI__Mastermind 23695 points

Yusuke-san,

If the EN pin voltage is less than the VREG votlage, there is no resistor on the node. If the EN pin voltage is greater than VREG, a pmos transistor is turned on with about 1000kOhm of resistors on the node.

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TPS53319: About EN pin