Linear Technology LT3480, Руководство пользователя

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LT3480
4
3480fb
TYPICAL PERFORMANCE CHARACTERISTICS
LOAD CURRENT (A)
0
50
EFFICIENCY (%)
100
0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 2.0 1.0
3480 G01
60
90
80
70
V
IN
= 24V
V
IN
= 34V
V
IN
= 12V
L: NEC PLC-0745-5R6
f: 800kHz
V
OUT
= 5V
0 0.2 0.4 0.6 0.8 1.2 1.4 1.6 1.8 2.0 1.0
LOAD CURRENT (A)
50
EFFICIENCY (%)
90
3480 G02
60
65
55
85
80
70
75
V
IN
= 12V
V
IN
= 7V
L: NEC PLC-0745-5R6
f: 800kHz
V
IN
= 24V
V
IN
= 34V
V
OUT
= 3.3V
LOAD CURRENT (A)
0
EFFICIENCY (%)
POWER LOSS (W)
40
30
0.5 1.0 1.5 2
3480 G27
60
50
90
80
70
0.01
0.1
10
1
V
IN
= 12V
V
OUT
= 3.3V
L = 5.6μH
F = 800 kHz
INPUT VOLTAGE (V)
0
SUPPL
Y CURRENT (μA)
15
3480 G04
40
20
5 10 20
0
120
100
80
60
25 30 35
V
OUT
= 3.3V
TEMPERATURE (°C)
–50
SUPPL
Y CURRENT (μA)
350
25
3480 G05
200
100
–25 0 50
50
0
400
300
250
150
75 100 150 125
V
IN
= 12V
V
OUT
= 3.3V
CATCH DIODE: DIODES, INC. PDS360
INCREASED SUPPLY
CURRENT DUE TO CATCH
DIODE LEAKAGE AT
HIGH TEMPERATURE
INPUT VOLTAGE (V)
5
LOAD CURRENT (A)
15
3480 G06
2.5
10 20
1.5
1.0
4.0
3.5
3.0
2.0
25 30
TYPICAL
MINIMUM
V
OUT
= 3.3V
T
A
= 25 °C
L = 4.7μH
f = 800 kHz
INPUT VOLTAGE (V)
5
LOAD CURRENT (A)
15
3480 G07
2.5
10 20
1.5
1.0
3.5
3.0
2.0
25 30
TYPICAL
MINIMUM
V
OUT
= 5V
T
A
= 25 °C
L = 4.7μH
f = 800kHz
DUTY CYCLE (%)
0
SWITCH CURRENT LIMIT(A)
40
3480 G08
2.5
20 60
1.5
1.0
4.0
3.5
3.0
2.0
80 100
TEMPERATURE (°C)
SWITCH CURRENT LIMIT (A)
2.0
2.5
3.5
3.0
3480 G09
1.5
1.0
0
0.5
4.5
4.0
DUTY CYCLE = 10 %
DUTY CYCLE = 90 %
–50 25 –25 0 50 75 100 150 125
Effi ciency Effi ciency Effi ciency
No Load Supply Current No Load Supply Current Maximum Load Current
Maximum Load Current Switch Current Limit Switch Current Limit