MAX1649_09 Datasheet, PDF (3/12 Pages) Maxim Integrated Products – 5V/3.3V or Adjustable, High-Efficiency, Low-Dropout, Step-Down DC-DC Controllers

5V/3.3V or Adjustable, High-Efficiency,
Low-Dropout, Step-Down DC-DC Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, T_A = T_MIN to T_MAX, unless otherwise noted. Typical values are at T_A = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
Current-Limit Trip Level
(V+ to CS)
V_CS 3V ≤ V+ ≤ 16V
CS Input Current
3V ≤ V+ ≤ 16V
Switch Maximum On-Time t_ON (max) V+ = 12V
Switch Minimum Off-Time t_OFF (min) V+ = 12V
EXT Rise Time
C_EXT = 0.001µF, V+ = 12V
EXT Fall Time
C_EXT = 0.001µF, V+ = 12V
Maximum Duty Cycle
t_ON
x 100%
t_ON + t_OFF
MIN TYP MAX
80
110
140
±1
24
32
40
0.8
1.1
1.8
25
25
95
96.5
UNITS
mV
µA
µs
µs
ns
ns
%
__________________________________________Typical Operating Characteristics
(T_A = +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
80
78
V+ = 16V
76
74
V+ = 10V
72
70
V+ = 4V
68
66
-60 -40 -20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
SHUTDOWN CURRENT
vs. TEMPERATURE
4.0
3.5
3.0
V+ = 16V
2.5
2.0
1.5
V+ = 8V
1.0
0.5
V+ = 4V
0
-60 -40 -20
0 20 40 60 80 100 120 140
TEMPERATURE (°C)
EXT RISE AND FALL TIMES
vs. TEMPERATURE (1nF)
60
C_EXT = 1nF
55
50
V+ = 5V, t_RISE
45
40
V+ = 5V, t_FALL
35
30
25
V+ = 15V, t_RISE
20
V+ = 15V, t_FALL
15
-60 -40 -20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
EXT RISE AND FALL TIMES
vs. TEMPERATURE (5nF)
240
220 ^{CEXT = 5nF}
200
V+ = 5V, t_RISE
180
160
V+ = 5V, t_FALL
140
120
V+ = 15V, t_RISE
100
80
60
V+ = 15V, t_FALL
40
-60 -40 -20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
EFFICIENCY
vs. LOAD CURRENT (V_OUT = 5V)
100
V_OUT = 5V
CIRCUIT OF
90 ^{FIGURE 1}
80
70
60
50
40
0.1
TOP TO
BOTTOM:
V_IN = 6V
V_IN = 8V
V_IN = 10V
V_IN = 12V
V_IN = 15V
1
10
100 1k 10k
LOAD CURRENT (mA)
EFFICIENCY
vs. LOAD CURRENT (V_OUT = 3.3V)
100
V_OUT = 3.3V
CIRCUIT OF
90 ^{FIGURE 1}
80
70
60
50
40
0.1
TOP TO
BOTTOM:
V_IN = 4.3V
V_IN = 5V
V_IN = 8V
V_IN = 10V
V_IN = 12V
V_IN = 15V
1
10
100 1k 10k
LOAD CURRENT (mA)
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