Datasheet

LT3958
5
3958fa
For more information www.linear.com/LT3958
Dynamic Quiescent Current
vs Switching Frequency
R
T
vs Switching Frequency
Normalized Switching
Frequency vs FBX
SWITCHING FREQUENCY (kHz)
100
0
I
Q
(mA)
4
6
12
300
500 600
700
2
8
10
200
400
900800
1000
3958 G04
SWITCHING FREQUENCY (kHz)
0
10
R
T
(kΩ)
100
1000
300
500 600
700
100 200
400
900800
1000
3958 G05
FBX VOLTAGE (V)
–0.8
0
NORMALIZED FREQUENCY (%)
20
40
60
80
120
–0.4
0 0.4 0.8
3958 G06
1.2 1.6
100
Switching Frequency
vs Temperature
SW Pin Current Limit
vs Temperature
TEMPERATURE (°C)
–50
275
SWITCHING FREQUENCY (kHz)
280
285
290
295
300
305
310
325
–25
0 25 7550
3958 G07
100 125
315
320
R
T
= 41.2k
TEMPERATURE (°C)
–50
3.6
SW PIN CURRENT LIMIT (A)
4.1
4.0
3.9
3.8
4.2
4.3
4.4
0
50
75
3.7
–25
25
100
125
3958 G08
SW Pin Current Limit
vs Duty Cycle
DUTY CYCLE (%)
0
3.6
3.7
3.8
3.9
SW PIN CURRENT LIMIT (A)
4.2
20 40 8060
4.4
4.1
4.0
4.3
100
3958 G09
Typical perForMance characTerisTics
Positive Feedback Voltage
vs Temperature, V
IN
Negative Feedback Voltage
vs Temperature, V
IN
Quiescent Current
vs Temperature, V
IN
T
A
= 25°C, unless otherwise noted.
TEMPERATURE (°C)
–50
1.590
REGULATED FEEDBACK VOLTAGE (V)
1.592
1.596
1.598
1.600
1.604
0
50
75
1.594
1.602
–25
25
100
125
3958 G01
V
IN
= 80V
V
IN
= 24V
V
IN
= 8V
V
IN
= INTV
CC
= 5V
TEMPERATURE (°C)
–50
–804
REGULATED FEEDBACK VOLTAGE (mV)
–802
–800
–798
–792
–794
0
50
75
–796
–25
25
100
125
3958 G02
V
IN
= 80V
V
IN
= 24V
V
IN
= 8V
V
IN
= INTV
CC
= 5V
TEMPERATURE (°C)
–50
1.4
QUIESCENT CURRENT (mA)
1.6
1.8
0
50
75
1.5
1.7
–25
25
100
125
3958 G03
V
IN
= 80V
V
IN
= 24V
V
IN
= INTV
CC
= 5V
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.