Datasheet

LT3972
6
3972fa
FB PIN ERROR VOLTAGE (mV)
–200
–50
V
C
PIN CURRENT (μA)
–20
0
20
0 200
50
3972 G19
–40
–100 100
40
10
–10
30
–30
Error Amp Output Current
TEMPERATURE (°C)
V
C
VOLTAGE (V)
1.50
2.00
2.50
3972 G22
1.00
0.50
0
CURRENT LIMIT CLAMP
SWITCHING THRESHOLD
–50 25–25 0 50 75 100 150125
LOAD CURRENT (mA)
1
INPUT VOLTAGE (V)
3.0
3.5
10000
3972 G20
2.5
2.0
10 100 1000
5.0
4.5
4.0
V
OUT
= 3.3V
T
A
= 25°C
L = 4.7μH
f = 800kHz
1 1000010 100 1000
LOAD CURRENT (mA)
INPUT VOLTAGE (V)
5.0
5.5
3972 G21
4.5
4.0
6.5
6.0
V
OUT
= 5V
T
A
= 25°C
L = 4.7μH
f = 800kHz
3972 G24
I
L
0.2A/DIV
V
SW
5V/DIV
V
OUT
10mV/DIV
5μs/DIV
V
IN
= 12V
V
OUT
= 3.3V
I
LOAD
= 10mA
TEMPERATURE (°C)
THRESHOLD VOLTAGE (%)
85
90
95
3972 G23
80
75
–50 25–25 0 50 75 100 150125
3972 G25
I
L
0.2A/DIV
V
SW
5V/DIV
V
OUT
10mV/DIV
V
IN
= 12V
V
OUT
= 3.3V
I
LOAD
= 110mA
1μs/DIV
3972 G26
I
L
0.5A/DIV
V
SW
5V/DIV
V
OUT
10mV/DIV
V
IN
= 12V
V
OUT
= 3.3V
I
LOAD
= 1A
1μs/DIV
Minimum Input Voltage Minimum Input Voltage
V
C
Voltages Power Good Threshold
Switching Waveforms; Transition
from Burst Mode Operation to Full
Frequency
Switching Waveforms; Full
Frequency Continuous Operation
Switching Waveforms;
Burst Mode Operation
T
A
= 25°C unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS