LM4755: Calculation of current passing through IC

Hi, Deepak,

We will take a look at this and will answer as soon as possible.

Best regards,
Luis Fernando Rodríguez S.

Hi Luis,

Did you get time to look into this?

Regards,

Deepak

Hi Deepak,

Unfortunately this device does not provides efficiency plots, those plots are useful to guess the device current.

However you can try by looking at the Output Power vs Power Dissipation plot, this can give an idea of the efficiency, and then based on that you can make a rough estimate of the current, based on the supply voltage.

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuator

Hi Ivan,

Thanks for the reply.

I looked for the Graph, Graphs are for the TO-220 Packages not for the DDPAK that i am using.

Power consumption also shown at RL=4OHM and 8OHM, in my case it is 45ohm.

P=V^2/R

P=(5*5)/45=O.55W

Looking at the Figure 22

Power Dissipation=4.5W

Output power=0.55w

Efficiency=12%

Could you please help me Getting power dissipation for RL=45ohm.. to have exact value?

Hi Ivan,

I even check the Tina simulation for the same load and Measured current through VCC (inserting Virtual Ammeter)->It shows 12mA Which is less than calculated by Efficiency perspective.

What is that Note 7 marked on Figure 40?

Deepak,

Note 7 says:
Note 7: The TO-263 Package is not recommended for VS > 16V due to impractical heatsinking limitations.

I think using the model is the best available option now, unfortunately there is no evaluation module available for this device and since it is legacy and fairly old device the information available is pretty much what is online already.

Best regards,
-Ivan Salazar
Applications Engineer - Low Power Audio & Actuator