Rainbow Electronics MAX744A - Manual (Page 12)

MAX730A/MAX738A/MAX744A
5V, Step-Down,
Current-Mode PWM DC-DC Converters
12 ______________________________________________________________________________________
C1
1.23V
1M
±35%
SS
R1
510k SS CLAMP
FROM SHDN
MAX730A
MAX738A
MAX744A
Figure 2. Block Diagram of Soft-Start Circuitry
MAX730A
MAX738A
MAX744A
SHDN
V+ 1
SS
3
GND REF
6 2
C6
0.01
µ F
CC
OUT
4
5
LX
7
D1
1N5817
L1 *
OUTPUT
+5V
C4 *
C5
330pF
C3 *
C2
1
µ F
8
R1
510k
C1
0.1 µ F
* SEE TABLE 2 FOR COMPONENT VALUES AND SUPPLIERS.
PART
MAX730A
MAX738A
MAX744A
INPUT SUPPLY RANGE (V)
6.0 to 11.0
6.0 to 16.0
10.2 to 16.0
6.0 to 9.0
9.0 to 16.0
GUARANTEED OUTPUT CURRENT AT 5V (mA)
450
450
750
500
750
NOTE: PIN NUMBERS REFER TO 8-PIN PACKAGES.
C7
2.2 µ F
OUTPUT
L2
25 µ H
FILTER
OUTPUT
MAX730A +5.2V TO +11.0V
MAX738A/MAX744A +6.0V TO +16.0V
OPTIONAL LOWPASS OUTPUT FILTER
Figure 3. Standard +5V Step-Down Application Circuit