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

AZ34063U

9

Jan. 2013 Rev. 1. 3

BCD Semiconductor Manufacturing Limited

Data Sheet

Typical Applications

Figure 14. 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

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 AZ34063U

R1 47k

R2

2.2k

C2

330

μF

28V/175mA

+

Rsc

0.22

6

7

8

1

2

3

4

V

OUT