MC34063A, MC33063A, NCV33063A
170 mH
L
8
7
1
180
S
R
Q
Q2
Q1
2
1N5819
I
pk
C
R
0.22
T
sc
OSC
3
6
5
V
in
12 V
V
C
CC
T
+
100
1.25 V
Ref
Reg
+
−
Comp.
1500
pF
4
1.0 mH
R2
47 k
V
out
28 V/175 mA
V
out
+
+
R1 2.2 k
100
330
C
O
Optional Filter
Test
Conditions
= 8.0 V to 16 V, I = 175 mA
Results
Line Regulation
Load Regulation
Output Ripple
Efficiency
V
in
V
in
V
in
V
in
V
in
30 mV = 0.05%
10 mV = 0.017%
400 mVpp
O
= 12 V, I = 75 mA to 175 mA
O
= 12 V, I = 175 mA
O
= 12 V, I = 175 mA
87.7%
O
Output Ripple With Optional Filter
= 12 V, I = 175 mA
40 mVpp
O
Figure 8. Step−Up Converter
http://onsemi.com
5