1.5A STEP-DOWN/STEP-UP/INVERTING DC-DC CONVERTER

AZ34063A

Data Sheet

8

Sep. 2006 Rev. 1. 3

BCD Semiconductor Manufacturing Limited

Typical Applications

Figure 10. Step-Up Converter (Note 5)

Note 5: This is a typical step-up converter configuration. In the steady state, if the resistor divider voltage at pin

5 is greater than the voltage in the non-inverting input, which is 1.25V determined by the internal reference, the

output of the comparator will go low. At the next swithching period, the output switch will not conduct and the

output voltage will eventually drop below its nominal voltage until the divider voltage at pin 5 is lower than 1.25V.

+

-

Ipk

B

1.25V

Reference

Regulator

A

5

S

R

Q

I

PK

C

T

OSC

V

C1

100

µF

R3 180

C

T

470pF

L1 150

µH

D1

1N5819

L2 1.0

µΗ

C3

100

µF

Optional

Filter

V

OUT

+

+

U1 AZ34063A

R1 47k

R2

2.2k

C2

330

µF

28V/175mA

+

Rsc

0.22

6

7

8

1

2

3

4

V

OUT