Rainbow Electronics MAX799 - Manual (Page 29)

MAX796/MAX797/MAX799
Step-Down Controllers with
Synchronous Rectifier for CPU Power
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MAX797
CSL
CSH
VL
SYNC REF GND
TO
VL
V+
Q1
Q2
FB
1000pF
R1
63.4k
0.1%
R2
200k
0.1%
10k
OUTPUT
3.3V ±1.8%
REMOTE
SENSE
POINT
BST
DH
LX
DL
PGND
SKIP
SS
SHDN
INPUT
4.7 µ F
0.33 µ F
0.01 µ F
R SENSE
V OUT
USE EXTERNAL REFERENCE
(MAX872) FOR BETTER ACCURACY.
ADJUST RANGE = 2.5V TO 4V AS SHOWN.
OMIT R2 FOR V OUT = 2.5V.
= V REF
(
1 + –––
) R1
R2
L1
MAX495
51k
5%
200k
5%
51k
5%
Figure 18. High-Accuracy Adjustable-Output Application
MAX797
CSL
CSH
VL
1N5819
SYNC REF
GND
V+
Si9410
Si9410
FB
-5V AT 1.5A
BST
DH
LX
DL
PGND
SKIP
INPUT
4.5V TO 25V
SHDN
0.33 µ F
0.1 µ F 4.7 µ F
22 µ F 22 µ F
1N4148
L1
0.025 Ω
150 µ F 150 µ F
L1 = DALE LPE6562-A093
Figure 19. Negative-Output (Inverting Topology) Power Supply
____________________________________________Application Circuits (continued)