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