TPS74401-EP: DROPOUT VOLTAGE vs IOUT Relationship

Ramesh M41

Prodigy 140 points

Part Number: TPS74401-EP

Hello,

I am planning to use TPS74401MRGWREP.

The design configuration as follows,

1. Vin = Vbias = 3.3V

2. Vout = 2.5V (Vin-Vout = 0.8V)

3. Iout = 2.3A

But in Typical characteristic Dropout voltage vs Iout relationship, Dropout is increasing as output current increases.

And my Question is,

1. will this regulation required high dropout at full load condition

2. Will it work for the above configuration, Because Vin-Vout=0.8V

Thanks,

Ramesh M

over 6 years ago

0 Jason Song over 6 years ago

TI__Mastermind 23361 points

Hi Ramesh,

1. will this regulation required high dropout at full load condition

With Vin and Vbias, the dropout value is higher than the headroom you currently have. For 3A load, the maximum dropout spec is 1.62V.

2. Will it work for the above configuration, Because Vin-Vout=0.8V

With Vin and Vbias, for 2.3A, the dropout number as shown is around 1.2V. You only have 0.8V headroom and the device does not have enough headroom for normal operation.

Regards,
Jason

0 Ramesh M41 over 6 years ago in reply to Jason Song

Prodigy 140 points

Thanks Jason.

Then I have to configure as,

Vbias=5V

Vin=3.3V

Vout=2.5V @2.3A

In this mode only 195mV drop (VDO max)

0 Ramesh M41 over 6 years ago in reply to Ramesh M41

Prodigy 140 points

Vbias=5V

Vin=3.3V

Vout=2.5V @2.3A

In this mode only 195mV drop (VDO max)

Is this configuration will work???

0 Jason Song over 6 years ago in reply to Ramesh M41

TI__Mastermind 23361 points

Hi Remesh,

Yes, with a Vbias - Vout > 1.62V, the dropout for this device at 3A has a dropout max for 190mV.

Regards,

Jason

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TPS74401-EP: DROPOUT VOLTAGE vs IOUT Relationship