5V/12V/15V or Adjustable, High-Efficiency,
Low I
Q
, Step-Up DC-DC Controllers
MAX770–MAX773
__________________________________________Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
MAX770
EFFICIENCY vs. OUTPUT CURRENT
(BOOTSTRAPPED)
MAX770–3-01
MAX771
EFFICIENCY vs. OUTPUT CURRENT
(BOOTSTRAPPED)
MAX770–3-02
MAX772
EFFICIENCY vs. OUTPUT CURRENT
(BOOTSTRAPPED)
V
OUT
= 15V, CIRCUIT OF FIGURE 2b
MAX772 SUBSTITUTED FOR MAX771
90
EFFICIENCY (%)
MAX770–3-03
100
V
IN
= 4V
100
V
IN
= 9V
90
EFFICIENCY (%)
V
IN
= 6V
100
90
EFFICIENCY (%)
80
80
80
70
V
IN
= 3V
60
V
IN
= 3.5V
V
OUT
= 5V
CIRCUIT OF
FIGURE 2a
0.001
0.01
0.1
1
70
V
IN
= 5V
60
50
0.001
V
IN
= 3V
V
OUT
= 12V
CIRCUIT OF
FIGURE 2b
0.1
1
70
60
V
IN
= 12V
V
IN
= 9V
V
IN
= 6V
V
IN
= 5V
V
IN
= 3V
0.001
0.01
0.1
1
50
OUTPUT CURRENT (A)
50
0.01
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
MAX771
EFFICIENCY vs. OUTPUT CURRENT
(NON-BOOTSTRAPPED)
MAX770–3-04
MAX770
LOAD CURRENT vs.
MINIMUM START-UP INPUT VOLTAGE
MAX770–3-05
MAX771
LOAD CURRENT vs.
MINIMUM START-UP INPUT VOLTAGE
V
OUT
= 12V
CIRCUIT OF
FIGURE 2b
MAX770–3-06
100
700
600
LOAD CURRENT (mA)
500
400
300
200
100
ABOVE 3.4V,
THE CIRCUIT
STARTS UP
UNDER
MAXIMUM
LOAD
CONDITIONS
1.0
1.5
2.0
2.5
3.0
V
OUT
= 5V
CIRCUIT OF
FIGURE 2a
500
V
OUT
= 12V
CIRCUIT OF
FIGURE 2c
V
IN
= 9V
400
LOAD CURRENT (mA)
EFFICIENCY (%)
90
V
IN
= 6V
V
IN
= 5V
80
300
200
100
0
3.5
2.0
2.5
3.0
70
0.001
0
0.01
0.1
1
10
OUTPUT CURRENT (A)
ABOVE 3.5V
THE CIRCUIT
STARTS UP
UNDER
MAXIMUM
LOAD
CONDITIONS
3.5
4.0
MINIMUM START-UP INPUT VOLTAGE (V)
MINIMUM START-UP INPUT VOLTAGE (V)
SUPPLY CURRENT vs. TEMPERATURE
V
OUT
= 12V, V
IN
= 5V
CIRCUIT OF FIGURE 2b
BOOTSTRAPPED MODE
ENTIRE
CIRCUIT
2
MAX770–3-07
SUPPLY CURRENT vs. SUPPLY VOLTAGE
V
OUT
= 12V
SUPPLY CURRENT (mA)
0.6
BOOTSTRAPPED
CIRCUIT OF
FIGURE 2b
MAX770–3-08
EXT RISE/FALL TIME vs. SUPPLY VOLTAGE
MAX770–3-09
4
0.8
250
200
EXT RISE/FALL TIME (ns)
SUPPLY CURRENT (mA)
3
C
EXT
= 2200pF
C
EXT
= 1000pF
C
EXT
= 446pF
C
EXT
= 100pF
150
0.4
100
1
SCHOTTKY DIODE
LEAKAGE EXCLUDED
0.2
NON-BOOTSTRAPPED
CIRCUIT OF FIGURE 2c
50
0
0
-75 -50 -25
0
25
50
75 100 125
TEMPERATURE (°C)
0
2
4
6
8
10
12
2
4
6
8
V+ (V)
10
12
SUPPLY VOLTAGE (V)
4
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
