TPS7A02: Unable to get 3.3V output voltage

Sundaresan Thangeswaran1

Intellectual 360 points

Part Number: TPS7A02

Hi,

I have bought the TPS7A0233PDBVR, TPS7A0233PDQNR from Mouser electronics

I have input 2.8 V and I am getting output of 2.7v and also it keep changing not a fixed voltage.

Both the Package SOT 23 and DQN not working for me.

I have attached schematic of both package. Could you please help me to resolve the issue.

SOT 23 package

DQN package

Regards,

Sundar

over 3 years ago

0 Juliette over 3 years ago

TI__Mastermind 18466 points

Hi Sundar,

In order to get a 3.3V output voltage from the TPS7A02, your input voltage needs to be Vout + Vdo. Your dropout voltage changes depending on the load, but if you're using a max load of 200mA, your Vin (minimum) needs to be 3.3+.270 = 3.57V.

Best,

Juliette

0 Sundaresan Thangeswaran1 over 3 years ago in reply to Juliette

Intellectual 360 points

Hi Juliette,

Thanks for the answer.

I thought it is a voltage regulator and gives 3.3V fixed output for variable input voltage.

Am I understood wrong?

What is the output voltage I can get for no load condition.

Regards,

Sundar

0 Juliette over 3 years ago in reply to Sundaresan Thangeswaran1

TI__Mastermind 18466 points

Hi Sundar,

So the information you see on the datasheet is the dynamic range of inputs the part can support with the fixed output, and not be damaged [not necessarily be functional]. Because of how an LDO works, the voltages can only step-down. A 3.3V part will only output that voltage if the input voltage is greater than the output voltage by the dropout voltage.

You can find more info on how LDO's function in the LDO Basics App Note.

If you need a part that can step up your voltage, you will have to look into Boost Converters.

Best,

Juliette

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TPS7A02: Unable to get 3.3V output voltage