User Manual

MAX649/MAX651/MAX652
5V/3.3V/3V or Adjustable, High-Efficiency,
Low I
Q
, Step-Down DC-DC Controllers
_______________________________________________________________________________________ 5
130
20
EXT RISE AND FALL TIMES
vs. TEMPERATURE (1nF)
120
t
RISE
&
t
FALL
(ns)
110
90
-60 -20 60 140
MAX649-A10
TEMPERATURE (°C)
20 100-40 0 8040 120
V+ = 5V, t
RISE
100
80
70
60
40
50
30
V+ = 5V, t
FALL
V+ = 12V, t
RISE
V+ = 12V, t
FALL
C
EXT
= 1nF
500
50
EXT RISE AND FALL TIMES
vs. TEMPERATURE (5nF)
450
t
RISE
&
t
FALL
(ns)
400
350
-60 -20 60 140
MAX649-A11
TEMPERATURE (°C)
20 100-40 0 8040 120
V+ = 5V, t
RISE
300
250
150
200
100
V+ = 5V, t
FALL
V+ = 12V, t
RISE
C
EXT
= 5nF
V+ = 12V, t
FALL
1000
0
0 0.2 0.4 0.6 0.8 1.0
1.2
1.4 1.6
DROPOUT VOLTAGE
vs. LOAD CURRENT
200
300
100
800
900
MAX649-A12
LOAD CURRENT (A)
DROPOUT VOLTAGE (mV)
600
500
700
400
MAX649, V
OUT
= 5V
MAX652, V
OUT
= 3V
MAX651, V
OUT
= 3.3V
1100
600
DROPOUT VOLTAGE
vs. TEMPERATURE
700
1000
DROPOUT VOLTAGE (mV)
900
800
MAX651
-60 -20 60 140
MAX649-A13
TEMPERATURE (°C)
20 100-40 0 8040 120
I
LOAD
= 1A
CIRCUIT OF FIGURE 1
MAX649
MAX652
250
0
REFERENCE OUTPUT RESISTANCE
vs. TEMPERATURE
50
200
REFRENCE OUTPUT RESISTANCE (Ω)
150
100
-60 -20 60 140
MAX649-A16
TEMPERATURE (°C)
20 100-40 0 8040 120
I
REF
= 10µA
I
REF
= 50µA
I
REF
= 100µA
235
185
CS TRIP LEVEL
vs. TEMPERATURE
195
225
CS TRIP LEVEL (mV)
215
205
-60 -20 60 140
MAX649-A14
TEMPERATURE (°C)
20 100-40 0 8040 120
190
200
230
220
210
1.506
1.492
REFERENCE OUTPUT VOLTAGE
vs. TEMPERATURE
1.494
1.504
REFRENCE OUTPUT (V)
1.502
1.500
-60 -20 60 140
MAX649-A15
TEMPERATURE (°C)
20 100-40 0 8040 120
1.498
1.496
____________________________Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)