5 V, S t e p -Do w n ,
Cu rre n t -Mo d e P WM DC-DC Co n ve rt e rs
FROM SHDN
R1
510k
SS CLAMP
SS
1M
±35%
C1
1.23V
MAX730A
MAX738A
MAX744A
Figure 2. Block Diagram of Soft-Start Circuitry
MAX730A +5.2V TO +11.0V
038/MX74A
MAX738A/MAX744A +6.0V TO +16.0V
OPTIONAL LOWPASS OUTPUT FILTER
C2
1µF
L2
25µH
FILTER
OUTPUT
C3*
8
V+
OUTPUT
C7
7
1
3
2.2µF
LX
SHDN
D1
1N5817
L1*
R1
510k
MAX730A
MAX738A
MAX744A
5
4
OUTPUT
+5V
OUT
CC
C5
330pF
PART
INPUT SUPPLY RANGE (V) GUARANTEED OUTPUT CURRENT AT 5V (mA)
C4*
SS
GND
MAX730A
6.0 to 11.0
6.0 to 16.0
10.2 to 16.0
6.0 to 9.0
450
450
750
500
750
REF
MAX738A
MAX744A
C1
0.1µF
6
2
C6
0.01µF
9.0 to 16.0
NOTE: PIN NUMBERS REFER TO 8-PIN PACKAGES.
*SEE TABLE 2 FOR COMPONENT VALUES AND SUPPLIERS.
Figure 3. Standard +5V Step-Down Application Circuit
12 ______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
