Rainbow Electronics MAX799 - Manual (Page 27)

MAX796/MAX797/MAX799
Step-Down Controllers with
Synchronous Rectifier for CPU Power
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MAX473
V+
INPUT
4.5V
TO 30V
Q1
Si9433DY
OR MMSF4P01
82pF
VL (5V)
20pF
1k
100k, 1% 1.5k
16k, 1%
REF
(2.505V)
MAIN
3.3V
OUTPUT
(CSL)
+3.3V
MAIN OUTPUT
+2.9V OUTPUT
AT 2A
STANDARD 3.3V
CIRCUIT
10 µ F 10 µ F
MAX797
SANYO OS-CON
Figure 14. 2.9V Low-Dropout Linear Regulator with Fast Transient Response
MAX797
CSL CSH
VL
SYNC
REF
GND
V+
Q1
FB
100k
100k
+5V AT 1A
BST
DH
LX
DL
PGND
2N7002
OPTIONAL SYNC AND LOW-VOLTAGE
START-UP CIRCUIT
SKIP
SHDN
V IN
2.5V TO 5.25V
C2
100 µ F
C3
100 µ F
0.33 µ F
0.033 Ω
0.01 µ F
C1
100 µ F
D1
1N4148
190kHz - 340kHz
1N4148
+3.3V
(EXTERNAL)
33k
4.7 µ F
L1
5 µ H
0.1 µ F
L1 = SUMIDA CDRH125, 5 µ H
D1 = MOTOROLA MBR130
C1 - C3 = AVX TPS 100
µ F, 10V
Q1 = SILICONIX Si9936 (BOTH SECTIONS)
OR MOTOROLA MMDF3N03L
Figure 15. Low-Noise Boost Converter for Cellular Phones
____________________________________________Application Circuits (continued)