LT3922
elecTrical characTerisTics The l denotes the sꢄecificltions which lꢄꢄuy over the fCuu oꢄerltinꢂ
temꢄerltCre rlnꢂe, otherwise sꢄecificltions lre lt TA = 25°ꢀ, VIN = 12V, VEN/UVLꢃ = 2V Cnuess otherwise noted.
PAꢁAMETEꢁ
ꢁeference
ꢀꢃNDITIꢃNS
MIN
TYP
MAX
UNITS
l
V
Voltage
I
I
= 0µA
= 500µA
1.97
1.985
2
2
2.03
2.015
V
V
REF
VREF
VREF
V
Pin Current Limit
V
= 0V, Current Out of Pin
3.2
mA
REF
REF
LED ꢀCrrent ꢁeꢂCultion
CTRL-Off Threshold (Falling)
CTRL-Off Rising Hysteresis
CTRL Pin Current
l
200
210
15
220
100
mV
mV
nA
V
= 2V
−100
CTRL
l
l
l
Sense Voltage (V −V
)
V
V
V
= 2V (100ꢀ), V = 24V
98
48.5
4
100
50
5
102
51.5
6
mV
mV
mV
ISP ISN
CTRL
CTRL
CTRL
ISP
(Analog Input)
= 0.75V (50ꢀ), V = 24V
ISP
= 0.3V (5ꢀ), V = 24V
ISP
ISP Pin Current
ISN Pin Current
V
V
V
= 24.1V, V = 24V, V
CTRL
= 2V
= 2V
75
75
µA
µA
ISP
ISP
ISP
ISN
= 24.1V, V = 24V , V
ISN
CTRL
Current Error Amplifier Transconductance
= 24V
140
µA/V
DCty ꢀycue ꢀontrou of LED ꢀCrrent
Sense Voltage (V −V
)
CTRL Duty = 75ꢀ (100ꢀ), V = 24V
99
49
4
100
50
5
101
51
6
mV
mV
mV
ISP ISN
ISP
(Duty Cycle Input)
CTRL Duty = 37.5ꢀ (50ꢀ), V = 24V
ISP
CTRL Duty = 15ꢀ (5ꢀ), V = 24V
ISP
CTRL Pulse Input High (V )
1.6
V
V
IH
CTRL Pulse Input Low (V )
0.4
IL
CTRL Pulse Input Frequency Range
Voutlꢂe ꢁeꢂCultion
10
200
kHz
l
FB Regulation Voltage
V
= 2V
1.175
−100
1.200
1000
1.225
100
V
nA
CTRL
FB Pin Current
FB in Regulation
Voltage Error Amplifier Transconductance
µA/V
INTV ꢁeꢂCultor
ꢀꢀ
INTV Voltage
2.7
3
3.3
V
CC
INTV Pin Current Limit
V
= 0V, Current Out of Pin
INTVCC
20
mA
CC
Power Stlꢂe
Peak Current Limit
2.0
15
2.3
25
2.6
35
A
ns
l
Bottom Switch Minimum Off-Time
Bottom Switch On-Resistance
Top Switch On-Resistance
ꢃsciuultor
140
155
mΩ
mΩ
l
l
Programmed Switching Frequency (f
)
SW
R = 45.3k, V
T
= 0V
SYNC/SPRD
= 0V
SYNC/SPRD
1880
175
2000
210
2120
245
kHz
kHz
T
R = 499k, V
Spread Spectrum Frequency Range
R = 45.3k, V
T
= 3V
SYNC/SPRD
= 3V
SYNC/SPRD
1880
175
2650
306
kHz
kHz
T
R = 499k, V
RT Pin Current Limit
V
= 0V, Current Out of Pin
75
1.4
0.2
µA
V
RT
SYNC/SPRD Threshold (Rising)
SYNC/SPRD Falling Hysteresis
SYNC/SPRD Pin Current
1.5
V
V
= 5V
−100
100
nA
SYNC/SPRD
3922f
3
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