5V, Step-Down,
Current-Mode PWM DC-DC Converters
MAX730A/MAX738A/MAX744A
__________________________________________Typical Operating Characteristics
(Circuit of Figure 3, T
A
= +25°C, unless otherwise noted.)
MAX730A
EFFICIENCY vs. OUTPUT CURRENT
100
(NOTES 3, 6)
90
EFFICIENCY (%)
EFFICIENCY (%)
V+ = 5.5V
80
V+ = 7V
V+ = 9V
70
V+ = 11V
90
100
MAX738A
EFFICIENCY vs. OUTPUT CURRENT
100
(NOTES 3, 6)
90
EFFICIENCY (%)
MAX744A
EFFICIENCY vs. OUTPUT CURRENT
(NOTE 3)
V+ = 6V
80
V+ = 8V
V+ = 12V
70
V+ = 16V
V+ = 6.0V
80
V+ = 9.0V
V+ = 12.0V
70
V+ = 16.0V
60
0
200
600
800
OUTPUT CURRENT (mA)
400
1000
60
0
200
600
800
OUTPUT CURRENT (mA)
400
1000
60
0
200
400
600
800
OUTPUT CURRENT (mA)
1000
MAXIMUM OUTPUT CURRENT vs.
SUPPLY VOLTAGE
1400
(NOTES 3, 6)
MAXIMUM OUTPUT CURRENT (mA)
MAXIMUM OUTPUT CURRENT (mA)
1200
1000
800
600
400
200
4
1400
MAXIMUM OUTPUT CURRENT vs.
SUPPLY VOLTAGE, NO R1
3.0
(NOTES 3, 6)
QUIESCENT SUPPLY CURRENT (mA)
2.5
2.0
1.5
1.0
0.5
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE
MAX730A, V+ = 9.0V
MAX738A, V+ = 12.0V
MAX744A, V+ = 12.0V
1200
MAX744A
MAX730A
1000
MAX738A
MAX744A
MAX738A
MAX730A
(NOTES 4, 5)
800
4
6
8
10
12
14
16
SUPPLY VOLTAGE (V)
6
8
10
12
14
16
0
-60 -40 -20 0
20 40 60 80 100 120 140 160
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
MAX738A/MAX744A
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE
2.5
QUIESCENT SUPPLY CURRENT (mA)
1000
MAX738A/MAX744A
PEAK INDUCTOR CURRENT
vs. OUTPUT CURRENT
20
STANDBY SUPPLY CURRENT
vs. TEMPERATURE
(NOTES 4, 5)
PEAK INDUCTOR CURRENT (mA)
2.0
800
STANDBY SUPPLY CURRENT (µA)
18
16
14
12
10
8
6
4
2
0
V+ = 16V
MAX738A/MAX744A
ONLY
V+ = 12V
MAX738A/MAX744A
ONLY
1.5
UNDERVOLTAGE
LOCKOUT HYSTERESIS
UNDERVOLTAGE
LOCKOUT ENABLED
600
1.0
400
V+ = 6.6V
V+ = 8.0V TO 16.0V
0.5
200
L1 = 100µH
C4 = 150µF
V+ = 9V
V+ = 6V
-60 -40 -20
0 20 40 60 80 100 120 140 160
0
0
2
4
6
8
10
12
14
16
0
0
100 200
300 400 500
600 700 800
4
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
