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7

APPLICATION IDEAS

In fig. 23 a circuit is suggested to obtain the regulated +3.3V output with a linear configuration instead of the

Magamp circuitry.

In this case the output of the E/A modulates the gate-source voltage of a power MOS in series with the power

stage.

In fig. 24 a simple and cheap latch circuit is showed to manage an OV fault on the Auxiliary output in the same

nected between the collector of Q1 and Cout pulls down the output of the auxiliary E/A: this has the same effect

of the OCP_bounce internal signal that guarantees the reduction of duty cycle.

Figure 23. Controlling a Linear Regulator with the Error Amplifier B

Figure 24. Auxiliary OVP without Crowbar

+3.3V

Bout

Binv

+1.25V

R

L

R

H

_

+

L6611

+5V

R

B

L

C

1

C

2

+12V

Z

C

+3.3V

Bout

Binv

+1.25V

R

L

R

H

_

+

L6611

+5V

R

B

L

C

1

C

2

+12V

Z

C

L6611

V

AUX

DMON

100

5K6

5K6

Q2

BC558

Q1

BC548

R

SET

C

DEL

Cout

D1

BAT42

L6611

V

AUX

DMON

100

5K6

5K6

Q2

BC558

Q1

BC548

R

SET

C

DEL

Cout

D1

BAT42