Can IR38165 VOUT be set without PMBUS or I2C? Similar to IR3846

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tomnewton
Level 1
Level 1
First like given First question asked Welcome!

I'm migrating a design from the IR3846 to the IR38165. 

If I do not use the PMBUS/I2C lines (pull them high), can I set VOUT by configuring the control loop in the same way as the IR3846? Basically, in the absence of PMBUS/I2C communication, will the IR38165 default to operating in the same analog way as the IR3846, or does it need to have a VOUT value sent to its registers in order to work.

Thanks

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1 Solution
Nishanth
Moderator
Moderator
Moderator
50 likes received 100 solutions authored 10 likes given

Hello @tomnewton,

Thank you for contributing to the Infineon community.

IR38165 cannot be operated similarly to an analog-only mode such as IR3846.

However, you can consider using IR3806X series SupIRBuck™ DC-DC Regulator based on your design.IR3806X  series does not have the INTEL SVID interface.

Steps in Analog mode configuration for IR3806X series:

Refer to the numbers highlighted in the below Figure.

Nishanth_0-1666245792282.png

  1. Select R connected to Rt/SYNC pin to determine the switching frequency
  2. Leave the ADDR pin floating for analog mode.
  3. Select OCset voltage (Vcc\Float\Gnd) to determine the Over Current  Protection limit. 
  4. Calculate compensation parameters
  5. Set the Vsns pin divider ratio to match the FB pin divider ratio.
  6. Connect a resistor of 100K Ohm from TRACK_EN to P1V8 to avoid OTP start-up issues.

Reference voltage setting in Analog mode for IR3806X series::

Analog mode comes with a predefined factory set configuration. A reference voltage of 0.5V is set at the feedback pin in the factory set configuration. We have to match the resistor divider of the Vsns pin and Fb pin in order to set the output voltage. It is to be noted that the parts that come with evaluation boards have a predefined reference voltage set at 1.2V.

Please feel free to reach out to us if you need further clarification on this topic. 

Regards,

Nishanth

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1 Reply
Nishanth
Moderator
Moderator
Moderator
50 likes received 100 solutions authored 10 likes given

Hello @tomnewton,

Thank you for contributing to the Infineon community.

IR38165 cannot be operated similarly to an analog-only mode such as IR3846.

However, you can consider using IR3806X series SupIRBuck™ DC-DC Regulator based on your design.IR3806X  series does not have the INTEL SVID interface.

Steps in Analog mode configuration for IR3806X series:

Refer to the numbers highlighted in the below Figure.

Nishanth_0-1666245792282.png

  1. Select R connected to Rt/SYNC pin to determine the switching frequency
  2. Leave the ADDR pin floating for analog mode.
  3. Select OCset voltage (Vcc\Float\Gnd) to determine the Over Current  Protection limit. 
  4. Calculate compensation parameters
  5. Set the Vsns pin divider ratio to match the FB pin divider ratio.
  6. Connect a resistor of 100K Ohm from TRACK_EN to P1V8 to avoid OTP start-up issues.

Reference voltage setting in Analog mode for IR3806X series::

Analog mode comes with a predefined factory set configuration. A reference voltage of 0.5V is set at the feedback pin in the factory set configuration. We have to match the resistor divider of the Vsns pin and Fb pin in order to set the output voltage. It is to be noted that the parts that come with evaluation boards have a predefined reference voltage set at 1.2V.

Please feel free to reach out to us if you need further clarification on this topic. 

Regards,

Nishanth