LT3474/LT3474-1
TYPICAL PERFORMANCE CHARACTERISTICS
LED Current vs V
ADJ
1000
T
A
= 25°C
800
1000
1200
V
ADJ
= V
REF
LED Current vs Temperature
700
600
Switch Voltage Drop
T
A
= 25°C
SWITCH VOLTAGE DROP (mV)
100
125
LED CURRENT (mA)
LED CURRENT (mA)
800
600
400
200
0
–50 –25
V
ADJ
= V
REF
/5
500
400
300
200
100
0
0
600
400
200
0
0
0.25
0.75
0.5
V
ADJ
(V)
1
1.25
3474 GO3
50
25
75
0
TEMPERATURE (°C)
1000
500
SWITCH CURRENT (mA)
1500
3474 G05
3474 G04
Current Limit vs Duty Cycle
2.5
Switch Current Limit vs
Temperature
2.5
2.5
Current Limit vs Output Voltage
T
A
= 25°C
2
2
CURRENT LIMIT (A)
2
MINIMUM (85°C)
CURRENT LIMIT (A)
1.5
1.5
CURRENT LIMIT (A)
TYPICAL
1.5
MINIMUM (125°C)
1
1
1
0.5
0.5
0.5
0
0
20
60
40
DUTY CYCLE (%)
80
100
3474 G06
0
–50
0
–25
50
25
0
75
TEMPERATURE (°C)
100
125
0
2
4
6
V
OUT
(V)
8
10
12
3474 G08
3474 G07
Oscillator Frequency vs R
T
600
T
A
= 25°C
Oscillator Frequency vs
Temperature
R
T
= 80.6k
Oscillator Frequency Foldback
600
T
A
= 25°C
R
T
= 80.6k
OSCILLATOR FREQUENCY (kHz)
OSCILLATOR FREQUENCY (kHz)
550
1000
OSCILLATOR FREQUENCY (kHz)
–25
75
0
25
50
TEMPERATURE (°C)
100
125
500
400
300
200
100
0
0
500
450
100
10
R
T
(kΩ)
3474 G09
100
400
–50
0.5
1
1.5
V
OUT
(V)
2
2.5
3474 G11
3474 G10
3474fd
4
LINER [ LINEAR TECHNOLOGY ]
