AN908 Datasheet, PDF (8/9 Pages) STMicroelectronics – APPLICATION NOTE

AN908 APPLICATION NOTE
APPLICATION IDEAS
Figure 11. Voltage Mode Regulator.
VCC 12V
C13
47∝F
C8
1∝F
C10
680pF
VCC
8
R13
4.7
9
VC
SYNC 1
VREF
4
R1
6.8K
2
RCT
7
SS
C9
220nF
10
3
6
5
12
13
15
14 ¹¹
SGND ISEN DC LIM DIS
OUT
DC
Q1
STP60N03L
R8 4.7
R2
COMP
10K
R5
C11
27K
VFB
PGND
D1
STPS10L2S
L1 2∝H
VI 5V±5%
C1-4
220∝F-10V
SANYO-OSCON
R9
820
R10
2.4K
V_O=3.3V
I_Omax=12.5A
C5-7
220∝F-10V
SANYO-OSCON
D99IN1068A
Figure 12. Simplified Schematic.
V_CC
C13
47µF
C20
220nF
V_i 5V±5%
L3
Q1 STP80N03
L1 2.6µH
SYNC V_CC V_C
18
9
DIS DC-LIM
14
15
C1-4 330µF-25V
LXF-NCC
L2 50T
D2
R3
D1
10K
STPS202S
R1
6.8K
VREF
4
RCT
2
L4990A
IC1
OUT
R8 4.7
ISEN
R6 510
C19
C10
1µF
680pF
12
11 5
6
7
C12
R7
220pF ^3.3
SGND PGND VFB COMP SS
R10
10K
R10a
10K
R11
2K
R12
22K
C11 150pF
R14
R5 27K
Q2 BC337
C21
220nF
R4 4.7K
R20
R16
R18
10K
6.2K
+B
-
C16
1µF
R19
1.5K
+A
D4
PWRG
-
R17
6.2K
C17
R20
+ D ^6.2K
-
LM339/A
IC2
R22 3K D3
EN
R9
1K
R23 R24 R25 R26
R21
10K
-C
+
D5
R21a 3K
Q3
BC327
D99IN1069
V_O=2V-3.5V
I_O=0.3A-12.5V
C5-8 330µF-5.3V
SANYO OSCON
D0
D1
D2
D3
8/9