Datasheet
LT3796/LT3796-1
3
3796fa
For more information www.linear.com/3796
ELECTRICAL CHARACTERISTICS
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN
Minimum Operating Voltage V
IN
Tied to INTV
CC
6 V
V
IN
Shutdown I
Q
EN/UVLO = 0V, PWM = 0V
EN/UVLO = 1.15V, PWM = 0V
1
12
µA
µA
V
IN
Operating I
Q
(Not Switching) R
T
= 82.5k to GND, FB1 = 1.5V 2.5 3 mA
V
REF
Voltage –100µA ≤ I
REF
≤ 10µA
l
1.97 2.015 2.06 V
V
REF
Pin Line Regulation 6V < V
IN
< 100V 1.5 m%/V
V
REF
Pin Load Regulation –100µA < I
REF
< 0µA 10 m%/µA
SENSE Current Limit Threshold
l
100 113 125 mV
SENSE Input Bias Current Current Out of Pin 60 µA
SS Sourcing Current SS = 0V 28 µA
SS Sinking Current ISP – ISN = 1V, SS = 2V 2.8 µA
Error Amplifier
Full Scale LED Current Sense Threshold
(V
(ISP-ISN)
)
ISP = 48V, CTRL ≥ 1.2V
ISP = 0V, CTRL ≥ 1.2V
l
l
243
243
250
250
257
257
mV
mV
9/10th LED Current Sense Threshold
(V
(ISP-ISN)
)
CTRL = 1V, ISP = 48V
CTRL = 1V, ISP = 0V
l
l
220
220
225
225
230
230
mV
mV
1/2 LED Current Sense Threshold
(V
(ISP-ISN)
)
CTRL = 0.6V, ISP = 48V
CTRL = 0.6V, ISP = 0V
l
l
119
119
125
125
131
131
mV
mV
1/10th LED Current Sense Threshold
(V
(ISP-ISN)
)
CTRL = 0.2V, ISP = 48V
CTRL = 0.2V, ISP = 0V
l
l
16
16
25
25
32
32
mV
mV
ISP/ISN Current Monitor Voltage (V
ISMON
) V
(ISP-ISN)
= 250mV, ISP = 48V, –50µA < I
ISMON
< 0 µA
V
(ISP-ISN)
= 250mV, ISP = 0V, –50µA < I
ISMON
< 0 µA
l
l
0.96
0.96
1
1
1.04
1.04
V
V
ISP/ISN Over Current Protection Threshold
(V
(ISP-ISN)
)
ISN = 48V
ISN = 0V
l
l
360
360
375
375
390
390
mV
mV
CTRL Input Bias Current Current Out of Pin, CTRL = 1.2V 50 200 nA
ISP/ISN Current Sense Amplifier Input
Common Mode Range
0 100 V
ISP/ISN Input Current Bias Current
(Combined)
PWM = 5V (Active), ISP = 48V
PWM = 0V (Standby), ISP = 48V
700
0
0.1
µA
µA
ISP/ISN Current Sense Amplifier g
m
V
(ISP-ISN)
= 250mV 400 µs
V
C
Output Impedance 2000 kΩ
V
C
Standby Input Bias Current PWM = 0V –20 20 nA
FB1, FB2 Regulation Voltage (V
FB
) ISP = ISN = 48V
ISP = ISN = 48V
l
1.230
1.238
1.250
1.250
1.270
1.264
V
V
FB1 Amplifier g
m
450 600 750 µS
FB2 Amplifier g
m
130 170 210 µS
FB1, FB2 Pin Input Bias Current FB = V
FB
100 200 nA
FB1 Open LED Threshold VMODE Falling, ISP = ISN = 48V V
FB
– 70mV V
FB
– 60mV V
FB
– 50mV V
C/10 Comparator Threshold (V
(ISP-ISN)
) VMODE Falling, FB1 = 1.25V, ISP = 48V
VMODE Falling, FB1 = 1.25V, ISN = 0V
25
25
mV
mV
FB1 Overvoltage Threshold FAULT Falling V
FB
+ 35mV V
FB
+ 50mV V
FB
+ 60mV V
FB2 Overvoltage Threshold TG Rising V
FB
+ 35mV V
FB
+ 50mV V
FB
+ 60mV V
V
C
Current Mode Gain (∆V
VC
/∆V
SENSE
) 4.2 V/V
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C, V
IN
= 24V, EN/UVLO = 24V, CTRL = 2V, PWM = 5V, unless otherwise noted.