LMZM23601: No load

Atsuo Nakano

Prodigy 70 points

Part Number: LMZM23601

Hi Ti,

We are considering LMZM23601 with the following configuration:
Module Type=Adjustable
Vin=24V
Vout=5V
Mode=FPWM

With this configuration, the output may become unloaded. Is this a problem?

Is a bleeder resistor or similar component necessary?

Best regards,

8 months ago

0 Joshua Austria 8 months ago

TI__Mastermind 32810 points

Hi Atsuo,

No, a bleeder resistor is not necessary. The device can remain unloaded and will still regulate.

Thank you,

Joshua Austria

0 Atsuo Nakano 8 months ago in reply to Joshua Austria

Prodigy 70 points

Hi Joshua,

Thank you for your response.

I would appreciate further clarification.

When operating in Mode=FPWM under no-load conditions, does the oscillation frequency change?

Best regards,

0 Joshua Austria 8 months ago in reply to Atsuo Nakano

TI__Mastermind 32810 points

Hi Atsuo,

In FPWM mode, the device should not have its oscillation frequency change in all load conditions.

The frequency can be reduced when your input-output voltage ratio results in a minimum on-time or minimum off-time limit, but that should not be a function of your load for the most part.

Thank you,

Joshua Austria

0 Atsuo Nakano 8 months ago in reply to Joshua Austria

Prodigy 70 points

Hi Joshua,

Thank you for your response.

Is it stated in the datasheet that in FPWM mode, the oscillation frequency remains constant even under no-load conditions?

Best regards,

+1 Joshua Austria 8 months ago in reply to Atsuo Nakano

TI__Mastermind 32810 points

Hi Atsuo,

Please see below the excerpt from section 7.3.7.1 of the datasheet:

Thank you,

Joshua Austria

Power management

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LMZM23601: No load