Datasheet

LT3971A/LT3971A-5
5
3971af
TYPICAL PERFORMANCE CHARACTERISTICS
Switch Current Limit
Switch Current Limit
Load Regulation
Switching Frequency
Maximum Load Current
Switch V
CESAT
Boost Pin Current Frequency Foldback
T
A
= 25°C, unless otherwise noted.
INPUT VOLTAGE (V)
LOAD CURRENT (A)
3971A G10
2.5
0.5
1.0
1.5
2.0
0
54025 30 35
TYPICAL
MINIMUM
201510
V
OUT
= 5V
LOAD CURRENT (mA)
LOAD REGULATION (%)
3971A G11
0.30
–0.25
–0.20
–0.15
–0.10
–0.05
0.20
0.15
0.10
0.05
0
0.25
–0.30
0 1200600 800 1000400200
REFERENCED FROM V
OUT
AT 0.5A LOAD
TEMPERATURE (°C)
FREQUENCY (kHz)
3971A G12
1000
650
900
850
800
750
700
950
600
–55 15535 65 125955–25
DUTY CYCLE (%)
SWITCH CURRENT LIMIT (A)
3971A G13
3.0
2.0
1.5
1.0
0.5
2.5
0
0 10060 804020
TEMPERATURE (°C)
SWITCH CURRENT LIMIT (A)
3971A G14
2.5
2.4
2.3
2.2
2.1
2.0
1.5
1.6
1.7
1.8
1.9
–55 –25 1551259565355
DUTY CYCLE = 30%
SWITCH CURRENT (mA)
V
CESAT
(mV)
3971A G15
600
400
300
200
100
500
0
0 1500500 750 1000 1250250
SWITCH CURRENT (mA)
BOOST PIN CURRENT (mA)
3971A G16
30
20
15
10
5
25
0
0 1500500 750 1000 1250250
FB PIN VOLTAGE (V)
0
SWITCHING FREQUENCY (kHz)
900
800
400
200
500
600
700
300
100
0
0.80.4
3971A G17
1.20.60.2 1
V
OUT
(% OF REGULATION VOLTAGE)
0
SWITCHING FREQUENCY (kHz)
900
800
700
600
500
400
300
200
100
0
8040
3971A G18
1006020
LT3971A-5 Frequency Foldback