TS4851

Application Information

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5 Application Information

5.1 BTL configuration principles

The TS4851 integrates 3 monolithic power amplifier having BTL output. BTL (Bridge Tied Load) means

that each end of the load is connected to two single-ended output amplifiers. Thus, we have:

Single ended output 1 = Vout1 = Vout (V)

Single ended output 2 = Vout2 = -Vout (V)

and

Vout1 - Vout2 = 2Vout (V)

The output power is:

For the same power supply voltage, the output power in BTL configuration is four times higher than the

output power in single ended configuration.

5.2 Power dissipation and efficiency

Hypotheses:

Regarding the load we have:

and

and

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

The power delivered by the supply voltage is:

Then, the power dissipated by each amplifier is

Pdiss = Psupply - Pout (W)

)

W

(

R

)

Vout

2

(

Pout

L

2

RMS

=

----------------- (A)

2

---------------------- (W)

AVG

= 2

-------------------- (A)

)

W

(

P

P

R

V

2

2

P

OUT

OUT

L

CC

diss

−

π

=