5 V/1 2 V/1 5 V o r Ad ju s t a b le , High-Effic ie nc y,
Low I , Ste p-Up DC-DC Controlle rs
Q
__________________________________________Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s
(T = +25°C, unless otherwise noted.)
A
MAX770
EFFICIENCY vs. OUTPUT CURRENT
(BOOTSTRAPPED)
MAX771
MAX772
EFFICIENCY vs. OUTPUT CURRENT
(BOOTSTRAPPED)
EFFICIENCY vs. OUTPUT CURRENT
(BOOTSTRAPPED)
100
100
100
90
V
OUT
= 15V, CIRCUIT OF FIGURE 2b
V
= 6V
V
IN
= 9V
IN
MAX772 SUBSTITUTED FOR MAX771
V
IN
= 4V
90
80
70
60
90
80
70
60
80
V
IN
= 3.5V
V
70
60
50
V
= 12V
= 9V
IN
V
V
IN
= 3V
V = 5V
IN
IN
V
= 6V
= 5V
= 3V
IN
= 5V
V
= 12V
OUT
OUT
V
IN
= 3V
V
CIRCUIT OF
FIGURE 2a
IN
CIRCUIT OF
FIGURE 2b
V
IN
0–MAX73
50
50
0.001
0.01
0.1
1
0.001
0.01
0.1
1
0.001
0.01
0.1
1
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
MAX771
MAX770
MAX771
EFFICIENCY vs. OUTPUT CURRENT
(NON-BOOTSTRAPPED)
LOAD CURRENT vs.
LOAD CURRENT vs.
MINIMUM START-UP INPUT VOLTAGE
MINIMUM START-UP INPUT VOLTAGE
700
600
500
400
500
400
100
90
V
= 12V
OUT
V
= 5V
V
= 12V
OUT
OUT
CIRCUIT OF
FIGURE 2c
CIRCUIT OF
FIGURE 2a
CIRCUIT OF
FIGURE 2b
V
= 9V
IN
V
IN
= 6V
= 5V
300
200
V
IN
300
200
100
0
ABOVE 3.5V
THE CIRCUIT
STARTS UP
UNDER
MAXIMUM
LOAD
CONDITIONS
ABOVE 3.4V,
THE CIRCUIT
STARTS UP
UNDER
80
70
100
0
MAXIMUM
LOAD
CONDITIONS
0.001
0.01
1
10
2.5
3.0
3.5
4.0
0.1
1.0
1.5
2.0
2.5
3.0
3.5
2.0
MINIMUM START-UP INPUT VOLTAGE (V)
MINIMUM START-UP INPUT VOLTAGE (V)
OUTPUT CURRENT (A)
EXT RISE/FALL TIME vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. TEMPERATURE
0.8
0.6
0.4
250
4
3
2
V
= 12V, V = 5V
IN
OUT
V
= 12V
OUT
CIRCUIT OF FIGURE 2b
BOOTSTRAPPED MODE
200
150
C
= 2200pF
= 1000pF
= 446pF
= 100pF
BOOTSTRAPPED
CIRCUIT OF
EXT
C
EXT
ENTIRE
CIRCUIT
FIGURE 2b
C
EXT
C
EXT
100
50
0
SCHOTTKY DIODE
LEAKAGE EXCLUDED
0.2
0
1
0
NON-BOOTSTRAPPED
CIRCUIT OF FIGURE 2c
12
12
10
10
2
6
8
6
8
4
2
4
-50 -25
0
-75
25 50 75 100 125
V+ (V)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
_______________________________________________________________________________________
4
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
