34063AM-E1 参数 Datasheet PDF下载

Data Sheet

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

Typical Applications

L1 150µH

AZ34063A

R3 180

8

B

A

S

R

Q

1

7

Rsc

0.22

Ipk

I

PK

OSC

C

T

2

D1

1N5819

V

IN

12V

+

C1

100µF

6

1.25V

Reference

Regulator

3

C

T

470pF

+

-

5

4

L2 1.0

µΗ

V

OUT

28V/175mA

R1 47k

V

OUT

+

Optional

Filter

U1 AZ34063A

R2

2.2k

+

C2

330

µF

C3

100

µF

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.

Then the output of the comparator will go high, the output switch will be allowed to conduct. Since V

PIN5

=V

OUT

*

R2/(R1+R2)=1.25(V), the output voltage can be decided by V

OUT

=1.25 * (R1+R2)/R2 (V).

Sep. 2006 Rev. 1. 3

BCD Semiconductor Manufacturing Limited

8