OPA2379: About Load(Output) current vs Supply current Graph

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Guru 21045 points

Part Number: OPA2379

Hi Team,

Could you please let us know “Load(Output) current vs Supply current Graph” if you have any information?

We understand that Quiescent Current per Amplifier(Iq) is 10uA(max) at VS = 5.5V, IO = 0.

However, we would like to know Supply current at IO = some conditions.

Regards,

Hide

over 4 years ago

0 Ron Michallick over 4 years ago

TI__Guru**** 150436 points

Hello Hide,

If output current is positive (flows out of the output pin) then that current increases V+ current by the same amount. V- current is unchanged.

If output current is negative (flows in to output pin) then that current increases V- current by the same amount. V+ current is unchanged.

0 Caro Walter over 4 years ago

TI__Mastermind 19357 points

Hey Hide,

Do you have an example of the graph that you are asking for?

I believe that using the equation below for supply current should answer the question to a specific system.

I_supply = I_quiescent + I_Load

Iq changes with temperature or supply voltage (Figure 12 and Figure 5 show these trends).

All the best,
Carolina

0 Hide over 4 years ago in reply to Caro Walter

Guru 21045 points

Hi Ron-san, Carolina-san,

Thank you for your prompt reply.

Carolina-san,

Our conditions are the following.

[Conditions]

-VS is 3.3V (V+ is 3.3V and V- is GND)

-Input signal (+IN) is 3.3V Square wave

-IOUT is from 0mA to 10mA

- Voltage follower circuit

Regards,

Hide

0 Ron Michallick over 4 years ago in reply to Hide

TI__Guru**** 150436 points

Hide,

A PMOS transistor (or PNP if you can accept base current loss) used as a 'high side switch' would do the job better.

The OPA2379 won't provide 10mA reliably. See figure 6 on page 6 of the data sheet.

0 Hide over 4 years ago in reply to Ron Michallick

Guru 21045 points

Hi Ron-san,

Thank you for kind support.

10mA is plan level.

Could you please let us know the maximum load current values at our conditions and “Load(Output) current vs Supply current Graph” if you have any information?

Regards,

Hide

0 Ron Michallick over 4 years ago in reply to Hide

TI__Guru**** 150436 points

Hide,

Here is the chart with a 330 ohm load line (10mA @ 3.3V)

So typically the output current would be dependent on temperature per the intersections.

Can you describe the load in more detail?

0 Hide over 4 years ago in reply to Ron Michallick

Guru 21045 points

Hi Ron-san,

Thank you very much for your help.

I greatly appreciate your cooperation.

Regards,

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OPA2379: About Load(Output) current vs Supply current Graph