# How can i find total power consumption of the device from its datasheet?

In datasheet which parameter should I consider as a power consumption of a device? What is Icc? what is Iin? To get total power consumed by device can I multiply input current Iin with input voltage Vin. P= Vin*Iin ?

Is this correct?

Only study the datasheet is enough to get the power consumption of any device?

Thanks!!

• Do you have a specific device in mind? Mar 31 '15 at 7:29
• Thank you for your response..How can I find power consumption of TPS7A7001 regulater?
– TmP
Mar 31 '15 at 8:57

How can I find power consumption of TPS7A7001 regulator?

Assuming that Vin = 2.5 volts and Vout = 1.8 volts with a 1A load (just me putting some numbers together), the first thing to note is that the voltage dropped across the regulator is 2.5v - 1.8v = 0.7v and this voltage multiplied by the 1 A current will produce heat directly from the device at a power of 0.7 watts.

The feedback resistors R1 and R2 (in series across the output) are, according to table 1 in the data sheet something like 100kohm and this will consume 32 micro watts (barely nothing compared to the main power dissipation above).

There is some ground pin current and this is only loosely specified as 3mA - this is drawn from the incoming power rail hence it will dissipate 2.5v x 3mA = 7.5mW (again this is trivial compared to the 700mW main dissipation.

Datasheets will give the typical and maximum values.

To find the actual power consumption, you have to find the current drawn from the sources. The sources includes the power supply (DC source) and the signal source. If you have $n$ number of sources, then power consuption can be calculated as:

$$P_{consumed} = \sum_{i=1}^{n} V_iI_i$$

Where $V_i$ is the voltage and $I_i$ is the current drawn from the $i^{th}$ source. You have to use RMS values of voltage and current for alternating sources.