TS4890IDT datasheet(34/46 Pages) STMICROELECTRONICS

Part #	TS4890IDT

Description	Rail-to-rail output 1 W audio power amplifier with standby mode active low

PDF	46 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

Logo

34 / 46 page

Application information

TS4890

34/46

DocID8396 Rev 7

5.4

Power dissipation and efficiency

Hypothesis:

•

Voltage and current in the load are sinusoidal (Vout and Iout)

•

Supply voltage is a pure DC source (Vcc)

Regarding the load we have:

and

Then, the average current delivered by the supply voltage is:

The power delivered by the supply voltage is Psupply = Vcc IccAVG (W).

Then, the power dissipated by the amplifier is Pdiss = Psupply - Pout (W)

and the maximum value is obtained when

and its value is

Remark: This maximum value is only depending on power supply voltage and load values.

The efficiency is the ratio between the output power and the power supply.

OUT

PEAK

ωtV

()

sin

OUT

-------------- A

()

OUT

PEAK

------------------- W

()

Icc

AVG

PEAK

πR

----------------- A

()

Pdiss

22Vcc

---------------------- P

OUT

OUT W

()

–

∂Pdiss

∂P

OUT

-------------------

Pdissmax

2Vcc

----------------- W

()

TS4890IDT Datasheet(PDF) 34 Page - STMicroelectronics

TS4890IDT Datasheet(HTML) 34 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

Datasheet Download

Link URL