Step-up dc-dc controller, Typical operating characteristics, Electrical characteristics (continued) – Rainbow Electronics MAX1771 User Manual
Page 3
MAX1771
12V or Adjustable, High-Efficiency,
Low I
Q
, Step-Up DC-DC Controller
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V, I
LOAD
= 0mA, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETERS
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
FB Input Current
I
FB
MAX1771C
±20
nA
MAX1771E
±40
MAX1771M
±60
SHDN Input High Voltage
V
IH
V+ = 2V to 16.5V
1.6
V
SHDN Input Low Voltage
V
IL
V+ = 2V to 16.5V
0.4
V
SHDN Input Current
±1
µA
V+ = 16.5V, SHDN = 0V or V+
Current-Limit Trip Level
V
CS
V+ = 5V to 16V
85
100
115
mV
CS Input Current
0.01
±1
µA
EXT Rise Time
V+ = 5V, 1nF from EXT to ground
55
ns
EXT Fall Time
V+ = 5V, 1nF from EXT to ground
55
ns
Note 1: Output voltage guaranteed using preset voltages. See Figures 4a–4d for output current capability versus input voltage.
Note 2: Output voltage line and load regulation depend on external circuit components.
75
100
125
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
60
65
75
70
80
85
90
95
100
1
10
100
10,000
1000
EFFICIENCY vs. LOAD CURRENT
(BOOTSTRAPED MODE)
LOAD CURRENT (mA)
EFFICIENCY (
%
)
V
IN
= 5V
V
IN
= 3V
V
IN
= 8V
V
IN
= 10V
V
OUT
= 12V
CIRCUIT OF
FIGURE 2a
MAX1771–01
60
65
75
70
80
85
90
95
100
1
10
100
10,000
1000
EFFICIENCY vs. LOAD CURRENT
(NON-BOOTSTRAPED MODE)
LOAD CURRENT (mA)
EFFICIENCY (
%
)
V
IN
= 5V
V
IN
=10V
V
IN
= 8V
V
OUT
= 12V
CIRCUIT OF
FIGURE 2b
MAX1771
–
02
0
2.00
LOAD CURRENT vs.
MINIMUM START-UP INPUT VOLTAGE
MAX1771-TOC3
MINIMUM START-UP INPUT VOLTAGE (V)
LOAD CURRENT (mA)
100
200
300
400
500
600
700
2.25
2.50
2.75
3.00
3.25
3.50
EXTERNAL FET THRESHOLD
LIMITS FULL-LOAD START-UP
BELOW 3.5V
V
OUT
= 12V, CIRCUIT OF FIGURE 2a
MAX1771C/E
MAX1771M