Data Sheet
1.5A STEP-DOWN/STEP-UP/INVERTING DC-DC CONVERTER
AZ34063A
Typical Applications (Continued)
8
7
1
B
A
S
R
Q
2
3
Ipk
L1
88 µΗ
I
PK
Rsc
0.24
C
T
OSC
6
VIN
4.5-6V
+
1.25V
Reference
Regulator
C1
100 µF
CT
470pF
+
D1
1N5819
-
5
4
U1 AZ34063A
L2 1.0 µΗ
VOUT
VOUT
-12V/100mA
R1 953
C3
100 µF
C2
1000 µF
+
+
R2
8.2k
Optional
Filter
Figure 12. Voltage Inverting Converter (Note 7)
Note 7: This is a typical inverting converter configuration. The working process in the steady state is similar to
step-up converter, the difference in this situation is that the voltage at the non-inverting pin of the comparator is
equal to 1.25V+VOUT, then VPIN5=VOUT*R2/(R1+R2)=1.25V+VOUT, so the output voltage can be decided by
VOUT=-1.25*(R1+R2)/R1 (V).
BCD Semiconductor Manufacturing Limited
Sep. 2006 Rev. 1. 3
10
BCDSEMI [ BCD SEMICONDUCTOR MANUFACTURING LIMITED ]
