Datasheet

4
LTC3718
3718fa
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Boost Converter Oscillator
Frequency vs Temperature
Boost Converter Current Limit
vs Duty Cycle
SHDN Pin Current vs V
SHDN
V
FB2
, Feedback Pin Voltage
TEMPERATURE (°C)
–50 –25 0 25 50 75 100
SWITCHING FREQUENCY (MHz)
3718 G01
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
0
V
IN
= 5V
V
IN
= 1.5V
SHDN PIN VOLTAGE (V)
012345
SHDN PIN BIAS CURRENT (µA)
3718 G02
50
40
30
20
10
0
T
A
= 25°C
DUTY CYCLE (%)
10 20 30 40 50 60 70 80
CURRENT LIMIT (mA)
3718 G03
1000
900
800
700
600
500
400
300
200
70°C
25°C
–40°C
TEMPERATURE (°C)
–50
FEEDBACK PIN VOLTAGE (V)
3718 G04
1.25
1.24
1.23
1.22
1.21
1.20
FIGURE 1 CIRCUIT
–25 0 25 50 75 100
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
as follows:
LTC3718EG: T
J
= T
A
+ (P
D
• 130°C/W)
Note 3: The LTC3718 is tested in a feedback loop that adjusts V
FB1
to
achieve a specified error amplifier output voltage (I
TH
).
Note 4: The LTC3718 is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 5: Current limit guaranteed by design and/or correlation to static test.
INPUT VOLTAGE (V)
1.5
1.7 1.9 2.1 2.3 2.5 2.7 2.9
V
OUT
/V
IN
(%)
3718 G06
50.00
49.95
49.90
49.85
49.80
49.75
49.70
49.65
LOAD = 0A
LOAD = 10A
FIGURE 1 CIRCUIT
LOAD = 1A
LOAD CURRENT (A)
EFFICIENCY (%)
100
90
80
70
60
50
40
30
20
10
0
0.01 1 10 100
3718 G05/TA01a
0.1
V
IN
= 2.5V
V
OUT
= 1.25V
FIGURE 1 CIRCUIT
Efficiency vs Load Current
V
OUT
/V
IN
Tracking Ratio vs Input
Voltage