MAX758AEPA Maxim Integrated Products, MAX758AEPA Datasheet - Page 10

• Manufacturer Part Number: MAX758AEPA
• Description: DC/DC Switching Regulators Adjustable PWM Step-Down Regulator
• Manufacturer: Maxim Integrated Products

as the temperature falls, and excessive ESR is the most
likely cause of trouble at temperatures below 0°C.
Sanyo OS-CON series through-hole and surface-mount
tantalum capacitors exhibit low ESR at temperatures
below 0°C. Refer to Table 2 for recommended capaci-
tor values and suggested capacitor suppliers.
The catch diode should be a Schottky or high-speed
silicon rectifier with a peak current rating of about 1A
for full-load (750mA) operation. The 1N5817 is a good
choice. The 330pF outer-loop compensation capacitor
Adjustable, Step-Down,
Current-Mode PWM Regulators
Table 1. Typical Soft-Start Times
10
R1 (kΩ)
R1 (kΩ)
______________________________________________________________________________________
None
None
None
None
None
None
None
None
None
None
510
510
510
510
510
510
510
510
510
510
510
510
MAX750A CIRCUIT CONDITIONS
MAX750A CIRCUIT CONDITIONS
V+ (V)
V+ (V)
11
11
12
16
12
12
12
16
12
6
9
9
9
9
9
6
9
9
9
9
7
7
Other Components
I
I
OUT
OUT
150
300
150
150
150
150
150
300
750
300
0
0
0
0
0
0
0
0
0
0
0
0
(mA)
(mA)
C4 (µF)
C4 (µF)
100
100
100
100
100
390
680
100
100
100
100
390
680
100
100
100
100
100
100
100
100
100
provides the widest input voltage range and best tran-
sient characteristics. For low-current applications, the
510kΩ resistor may be omitted (see the Maximum
Output Current vs. Supply Voltage, R1 Removed graph
in the Typical Operating Characteristics ).
A good layout is essential for clean, stable operation.
The layouts and component placement diagrams given
in Figures 4-7 have been successfully tested over a
wide range of operating conditions. The 1µF bypass
capacitor (C2) must be positioned as close to the V+
C1 = 0.01
C1 = 0.01
16
10
34
39
40
12
27
2
1
1
1
1
3
4
8
1
1
1
1
1
7
6
SOFT-START TIME (ms) vs. C1 (µF)
SOFT-START TIME (ms) vs. C1 (µF)
C1 = 0.047
C1 = 0.047
134
147
152
112
34
22
18
27
16
13
6
4
2
4
5
6
6
4
2
1
3
5
Printed Circuit Layouts
C1 = 0.1
C1 = 0.1
270
280
285
215
11
51
34
28
40
25
20
6
4
8
9
9
9
6
3
2
5
8
C1 = 0.47
C1 = 0.47
1263
1275
1280
1114
125
100
28
15
11
21
27
23
24
82
66
18
21
54
68
8
6
3