Datasheet

LT3971/LT3971-3.3/LT3971-5
7
3971fd
TYPICAL PERFORMANCE CHARACTERISTICS
5V Start-Up and Dropout
Switching Waveforms; Full
Frequency Continuous Operation
Boost Diode Forward Voltage Power Good Threshold
3.3V Start-Up and Dropout
Switching Waveforms;
Burst Mode Operation
T
A
= 25°C, unless otherwise noted.
Transient Load Response,
Load Current Stepped from
0.5A to 1A
Transient Load Response,
Load Current Stepped from 25mA
(Burst Mode Operation) to 525mA
BOOST DIODE CURRENT (mA)
BOOST DIODE VF (V)
3971 G22
1.6
0.4
0.2
1.2
1.0
0.8
0.6
1.4
0
0 1500500 750 12501000250
TEMPERATURE (°C)
THRESHOLD VOLTAGE (%)
3971 G23
95
88
87
86
93
92
91
90
89
94
85
–55 15535 65 125955–25
10µs/DIV
3971 G25
V
OUT
100mV/
DIV
I
L
500mA/
DIV
V
IN
= 12V, V
OUT
= 3.3V
C
OUT
= 47µF
10µs/DIV
3971 G24
V
OUT
100mV/DIV
I
L
500mA/DIV
V
IN
= 12V, V
OUT
= 3.3V
C
OUT
= 47µF
5µs/DIV
3971 G26
V
SW
5V/DIV
V
OUT
20mV/DIV
I
L
500mA/DIV
V
IN
= 12V, V
OUT
= 3.3V
I
LOAD
= 10mA
C
OUT
= 22µF
1µs/DIV
3971 G27
V
SW
5V/DIV
V
OUT
20mV/DIV
I
L
500mA/DIV
V
IN
= 12V, V
OUT
= 3.3V
I
LOAD
= 1A
C
OUT
= 22µF
3.3V Start-Up and Dropout
0.5s/DIV
3971 G31
V
IN
1V/DIV
800kHz
3kΩ LOAD
V
OUT
0.5s/DIV
3971 G32
V
IN
1V/DIV
800kHz
6.7Ω LOAD
V
OUT
0.5s/DIV
3971 G33
1V/DIV
800kHz
5kΩ LOAD
V
OUT
V
IN