MAX730ACPA Maxim Integrated Products, MAX730ACPA Datasheet - Page 9

• Manufacturer Part Number: MAX730ACPA
• Description: DC/DC Switching Converters 5V Step-Down DC/DC Converter
• Manufacturer: Maxim Integrated Products

Specifications of MAX730ACPA

• Output Voltage: 5 V
• Switching Frequency: 185 KHz
• Maximum Operating Temperature: + 70 C
• Mounting Style: Through Hole
• Package / Case: PDIP-8
• Minimum Operating Temperature: 0 C
• Supply Current: 3 mA

Table 1. Typical Soft-Start Times
The +1.23V bandgap reference supplies up to 100µA
at REF. Connect a 0.01µF bypass capacitor from REF
to GND.
The internal oscillator of the MAX730A typically oper-
ates at 170kHz (160kHz for the MAX738A and 185kHz
for the MAX744A). The MAX744A is guaranteed to
operate at a minimum of 159kHz and a maximum of
212.5kHz over the operating voltage and temperature
range, making it ideal for use in portable communica-
tions systems. The Typical Operating Characteristics
graphs indicate oscillator frequency stability over tem-
perature and supply voltage.
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
MAX738A/MAX744A CIRCUIT CONDITIONS
MAX730A 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
Current-Mode PWM DC-DC Converters
I
I
OUT
OUT
Internal Reference
150
300
150
150
150
150
150
300
750
300
0
0
0
0
0
0
(mA)
0
0
0
0
0
0
(mA)
Oscillator
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
C1 = 0.01
C1 = 0.01
____________Applications Information
Figure 3 shows the standard 5V step-down application
circuits. Table 3 lists the components for the desired
operating temperature range. These circuits are useful
in systems that require high current at high efficiency
and are powered by an unregulated supply, such as a
battery or wall-plug AC-DC transformer. These circuits
operate over the entire line, load, and temperature
ranges using the single set of component values shown
in Figure 3 and listed in Table 3.
The MAX730A/MAX738A/MAX744A require no inductor
design because they are tested in-circuit, and are
guaranteed to deliver the power specified in the
Electrical Characteristics with high efficiency using a
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
112
27
16
13
134
147
152
4
2
1
3
5
34
22
18
6
4
2
4
5
6
6
5V, Step-Down,
C1 = 0.1
C1 = 0.1
270
280
285
215
Inductor Selection
11
51
34
28
40
25
20
6
4
8
9
9
9
6
3
2
5
8
C1 = 0.47
C1 = 0.47
1114
1263
1275
1280
100
125
18
21
54
68
28
15
11
21
27
23
24
82
66
8
6
3
9