LT3922
Typical perForMance characTerisTics VIN = 12V, TA = 25°C, u nless otherwise noted.
VISP – VISN vs VCTRL
VISP – VISN vs DCTRL
VISP – VISN vs VFB
125
100
75
50
25
0
125
100
75
50
25
0
125
100
75
50
25
0
PULSE FREQUENCY AT CTRL PIN = 20kHz
0
0.25 0.50 0.75
1
1.25 1.50 1.75
(V)
2
0
12.5 25 37.5 50 62.5 75 87.5 100
(%)
1.17
1.18
1.19
1.20
(V)
FB
1.21
1.22
V
D
V
CTRL
CTRL
3922 G19
3922 G20
3922 G21
5% Cu rrent Regu lation
ISMON Voltage
100% Cu rrent Regu lation
200
160
120
80
350
300
250
200
150
100
50
1000
800
600
400
200
0
150°C
25°C
–40°C
–40°C
25°C
125°C
150°C
25°C
–40°C
N = 355
N = 355
40
0
0
4.2
4.6
ISP–ISN VOLTAGE (mV)
= 0.3V
5
5.4
5.8
98.6
99.3
100
100.7
101.4
0
20
40
60
80
100
ISP–ISN VOLTAGE (mV)
V
– V (mV)
ISP
ISN
3922 G23
3922 G22
3922 G24
V
= 2V
CTRL
V
CTRL
V
= 24V
ISP
V
= 24V
ISP
Peak SW Cu rrent Limit
I
LED vs VIN
ILED vs VOUT
2.6
2.5
2.4
2.3
2.2
2.1
2.0
1.9
1.8
400
350
300
250
200
150
100
50
400
350
300
250
200
150
100
50
f
= 2MHz
SW
V
OVERVOLTAGE PROTECTION LIMITED
FB
L = 4.7µH
PEAK SW CURRENT LIMITED
V
SW
R
R
R
= 8V
IN
f
= 2MHz
= 0.3Ω
f
= 2MHz
SNS
SW
12 LEDs (V
~ 36V)
= 1M
R
= 0.3Ω
OUT
FB_TOP
FB_BOT
SNS
6 LEDs (V
~ 18V)
= 34.8k
11 LEDs (V
~33V)
OUT
OUT
10 20 30 40 50 60 70 80 90 100
0
3
6
9
12 15 18 21 24 27 30
(V)
9
15
21
V
OUT
27
(V)
33
39
DUTY CYCLE (%)
V
IN
3922 G25
3922 G26
3922 G27
3922f
7
For more information www.linear.com/LT3922
Linear Systems [ Linear Systems ]
