Audio characteristics

AN2583

10/18

2.2.3

Getting more power

One technique for increasing the deliverable power is to add a negative supply equal in

magnitude to the positive supply. This is depicted in Figure 10. With this addition, the

thus removing any frequency roll off effects due to using an imperfect, real-world capacitor.

Figure 10.

Amplifier with symmetric supplies

Figure 11.

Output of amplifier with symmetric supplies

As before, the continuous power to the load is

Thus, compared to Equation 1, by adding the negative supply, the maximum power

circuit of Figure 7.

But either way, adding a supply or doubling the voltage can be costly. It is preferred to get

the increase in power without such additional costs.

+

–

+

–

+

–

Q2

Q1

GND

ai13936

0

ai13937

L

2

PK

-

L

AV

-

L

R

2

V

P

=

L

2

DD

L

2

PK

-

L

max

-

AV

-

L

R

2

V

R

2

V

P

=

=