Diodes AZ34063U - Manual (Page 11)

1.5A STEP-DOWN/STEP-UP/INVERTING DC-DC CONVERTER AZ34063U
11
Jan. 2013 Rev. 1. 3 BCD Semiconductor Manufacturing Limited
Data Sheet
Figure 16. Voltage Inverting Converter (Note 7)
Typical Applications (Continued)
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+V
OUT
, then V
PIN5
=V
OUT
*R2/(R1+R2)=1.25V+V
OUT
, so the output voltage can be decided by
V
OUT
=-1.25*(R1+R2)/R1 (V).
+
-
Ipk
B
1.25V
Reference
Regulator
A
8
S
R
Q
I
PK
C
T OSC
V
IN
4.5-6V
C1
100 μF
Rsc
0.24
L2 1.0 μΗ
Optional
Filter
V
OUT
D1
1N5819
L1
88 μΗ
+
C3
100 μF +
C
T
470pF
R1 953
R2
8.2k
C2
1000 μF
-12V/100mA
+
U1 AZ34063U
7
6
5 4
3
2
1
V
OUT