4A, Low-Noise, High-Frequency,
Step-Up DC-DC Converter
MAX1709
Typical Operating Characteristics (continued)
(Circuit of Figure 1, T
A
= +25°C, unless otherwise noted.)
SWITCH CURRENT LIMIT
vs. SS/LIM RESISTANCE
MAX1709 TOC10
SWITCH CURRENT LIMIT
vs. TEMPERATURE
MAX1709-12
HEAVY SWITCHING WAVEFORM
MAX1709-13a
10
9
8
CURRENT LIMIT (A)
7
6
5
4
3
2
50
100
150
200
250
11.5
11.0
CURRENT LIMIT (A)
10.5
10.0
5V
0
V
LX
5V/div
5V
9.5
9.0
8.5
8.0
V
OUT
= 3.3V
4A
2A
I
OUT
= 2A
V
OUT
100mV/div
I
L
2A/div
300
-40
-15
10
35
60
85
1μs/div
SS/LIM RESISTANCE (kΩ)
TEMPERATURE (°C)
HEAVY SWITCHING WAVEFORM
(WITH LC FILTER)
MAX1709-13b
LINE-TRANSIENT
RESPONSE
MAX1709-14
LOAD-TRANSIENT
RESPONSE
MAX1709-15
5V
0
V
LX
5V/div
3.5V
3V
5V
V
OUT
100mV/div
3A
1A
V
IN
0.5V/div 5V
I
OUT
2A/div
V
OUT
100mV/div
6A
4A
2A
I
L
2A/div
5V
V
OUT
4A
50mV/div
2A
I
OUT
= 1A
1μs/div
I
OUT
= 2A
L = 12.5nH (COILCRAFT A04T)
C = 1μF
100μs/div
20μs/div
I
L
2A/div
SHUTDOWN WITH SOFT-START
(C
SS
= 0.1μF)
5V
0
MAX1709-16
SHUTDOWN WITH SOFT-START
(C
SS
= 0.01μF)
5V
0
6A
SHUTDOWN WITHOUT SOFT-START
MAX1709-18
MAX1709-17
V
ONA
5V/div
V
ONA
5V/div
5V
0
6A
V
ONA
5V/div
4A
2A
0
4V
2V
1ms/div
C
SS
= 0.1μF
R
OUT
= 5Ω
V
ONB
= V
OUT
I
IN
2A/div
4A
2A
0
I
IN
2A/div
4A
2A
0
I
IN
2A/div
V
OUT
2V/div
4V
2V
1ms/div
C
SS
= 0.01μF
R
OUT
= 5Ω
V
ONB
= V
OUT
V
OUT
2V/div
4V
2V
1ms/div
C
SS
= 0
R
OUT
= 5Ω
V
ONB
= V
OUT
V
OUT
2V/div
6
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
