UTCTDA2030 LINEAR INTEGRATED CIRCUIT

12

QW-R107-004,B

It is essential to take into account all the working conditions, in particular mains fluctuations and supply voltage

variations with and without load. The UTC2030(Vsmax=44V) is particularly suitable for substitution of the standard

IC power amplifiers(with Vsmax=36V) for more reliable applications.

An example, using a simple full-wave rectifier followed by a capacitor filter, is shown in the table and in the diagram

of Fig.27.

A regulated supply is not usually used for the power output stages because of its dimensioning must be done

taking into account the power to supply in signal peaks. They are not only a small percentage of the total music

signal, with consequently large overdimensioning of the circuit.

Even if with a regulated supply higher output power can be obtained(Vs is constant in all working conditions),the

additional cost and power dissipation do not usually justify its use. using non-regulated supplies, there are fewer

designee restriction. In fact, when signal peaks are present, the capacitor filter acts as a flywheel supplying the

required energy.

In average conditions, the continuous power supplied is lower. The music power/continuous power ratio is greater

in case than for the case of regulated supplied, with space saving and cost reduction.

0

0.4

0.8

1.2

1.6

2.0

28

30

32

34

36

Vo(V)

Io(A)

Fig.27 DC characteristics of

50W non-regulated supply

Vo

3300

µF

220V

0

2

4

Ripple

(Vp-p)

Ripple

Vout

Mains(220V)

Secondary Voltage

DC Output Voltage(Vo)

Io=0

Io=0.1A

Io=1A

+20%

28.8V

43.2V

42V

37.5V

+15%

27.6V

41.4V

40.3V

35.8V

+10%

26.4V

39.6V

38.5V

34.2V

—

24V

36.2V

35V

31V

-10%

21.6V

32.4V

31.5V

27.8V

-15%

20.4V

30.6V

29.8V

26V

-20%

19.2V

28.8V

28V

24.3