ꢀ ꢁꢂ ꢂ ꢃ ꢄ ꢂꢅ ꢆ ꢀ ꢁꢂ ꢇꢃ ꢄꢂ ꢅ
ꢈ ꢉ ꢊ ꢋꢅ ꢌ ꢍꢅ ꢎ ꢏꢐ ꢐ ꢑꢒ ꢓꢏꢔ ꢁꢎꢓ ꢕꢖꢗ ꢍꢘꢒ ꢕꢖ ꢙ ꢑꢚ ꢕ ꢒꢁ ꢛꢕꢖ ꢙ ꢘꢍꢙ ꢔ ꢜꢅꢒꢐ ꢘꢑ
SLLS636D – DECEMBER 2004 – REVISED MARCH 2005
TYPICAL CHARACTERISTICS
170 µH
L
1
8
180 Ω
Q2
S
R
Q
1N5819
Q1
2
3
7
6
I
R
pk
SC
0.22 Ω
C
T
V
in
12 V
C
V
CC
T
1500 pF
1.25-V
Reference
Regulator
+
+
_
100 µF
Comparator
4
5
1.0 µH
100 µF
R2
47 kΩ
V
out
28 V/175 mA
V
out
+
C
O
+
R1
2.2 kΩ
330 µF
Optional Filter
RESULTS
TEST
CONDITIONS
= 8 V to 16 V, I = 175 mA
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%
O
= 12 V, I = 75 mA to 175 mA
O
= 12 V, I = 175 mA
400 mV
87.7%
O
PP
= 12 V, I = 175 mA
O
Output Ripple With Optional Filter
= 12 V, I = 175 mA
40 mV
PP
O
Figure 6. Step-Up Converter
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TI [ TEXAS INSTRUMENTS ]
