SI9138 Datasheet, PDF (11/14 Pages) Vishay Siliconix – Multi-Output, Individual On/Off Control Power-Supply Controller

New Product
Si9138
Vishay Siliconix
DETAILED FUNCTIONAL BLOCK DIAGRAMS
+
1X_
REF
SLC
Error
– ^Amplifier
+
PWMCMP
–
+
Pulse
Skipping
Control
ON 3 or ON 5
Logic
Control
20 mV
V
Soft-Start
t
Current
Limit
SYNC
Rectifier Control
FB₅
CS_
FB_
BST_
DH
DH
R_{X Internal voltage divider is}
only used on 5-V output.
R_Y
LX_
BBM
V_L
DL
DL
FIGURE 5. Buck Block Diagram (3.3-V and 5-V Controllers)
REF
COMP
Error
Amplifier
–
+
CSP
CSN
C/S
Amplifier
–
+
100 mV
V
Soft-Start
t
PWM
Comparator
–
+
ON 5
Logic
Control
Pulse
Skipping
Control
–
+
Current Limit
BSTFY
DH
LXFY
DL
FBFY
R₂
R₃
DHFY
DLFY
Document Number: 71446
S-20642—Rev. B, 13-May-02
FIGURE 6. Buck-Boost Block Diagram (5- to 12-V adjustable controller)
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