LT3762E/LT3762I ................................... –40°C to 125°C
LT3762H ................................................ –40°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
PIN CONFIGURATION
TOP VIEW
EN/UVLO
OPENLED
SHORTLED
PWM
DIM
RT
SSFM
SS
V
REF
1
2
3
4
5
6
7
8
9
29
GND
28 INTV
CC
27 AUXSW2
26 AUXBST
25 AUXSW1
24 V
IN
23 SNSP
22 SNSN
21 BG
20 BOOST
19 SW
18 TG
17 ISP
16 ISN
15 PWMTG
PWM 1
DIM 2
RT 3
SSFM 4
SS 5
V
REF
6
CTRL1 7
CTRL2 8
9 10 11 12 13 14
FB
PWMTG
ISN
GND
ISP
V
C
29
GND
SHORTLED
TOP VIEW
OPENLED
EN/UVLO
AUXSW2
AUXBST
22 AUXSW1
21 V
IN
20 SNSP
19 SNSN
18 BG
17 BOOST
16 SW
15 TG
INTV
CC
28 27 26 25 24 23
CTRL1 10
CTRL2 11
V
C
12
FB 13
GND 14
FE PACKAGE
28-LEAD PLASTIC TSSOP
θ
JA
= 30°C/W,
θ
JC
= 10°C/W
EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB
UFD PACKAGE
28-LEAD (4mm
×
5mm) PLASTIC QFN
θ
JA
= 43°C/W,
θ
JC
= 3.4°C/W
EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT3762EFE#PBF
LT3762IFE#PBF
LT3762HFE#PBF
LT3762EUFD#PBF
LT3762IUFD#PBF
LT3762HUFD#PBF
TAPE AND REEL
LT3762EFE#TRPBF
LT3762IFE#TRPBF
LT3762HFE#TRPBF
LT3762EUFD#TRPBF
LT3762IUFD#TRPBF
LT3762HUFD#TRPBF
http://www.linear.com/product/LT3762#orderinfo
PART MARKING*
LT3762
LT3762
LT3762
3762
3762
3762
PACKAGE DESCRIPTION
28-Lead Plastic TSSOP
28-Lead Plastic TSSOP
28-Lead Plastic TSSOP
28-Lead Plastic QFN
28-Lead Plastic QFN
28-Lead Plastic QFN
TEMPERATURE RANGE
-40°C to 125°C
-40°C to 125°C
-40°C to 150°C
-40°C to 125°C
-40°C to 125°C
-40°C to 150°C
Consult ADI Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
Rev 0
2
For more information
www.analog.com
LT3762
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 24V; CTRL1, CTRL2, PWM = 2V; SW, SSFM = 0V;
INTV
CC
, BOOST, DIM = 8V unless otherwise noted.
PARAMETER
V
IN
Minimum Operation Voltage
V
IN
Overvoltage Lockout
V
IN
Shutdown I
Q
V
IN
Operating I
Q
(Not Switching)
INTV
CC
Operating I
Q
(Not Switching)
V
REF
Voltage
V
REF
Line Regulation
Switch Current Sense Limit Threshold
Current Sense Zero Cross Detect Threshold Hysteresis
V
SNSP-SNSN
V
SNSP, SNSN
Synchronous Driver Enable
SNSP, SNSN Input Bias Current (Low-Side Sensing)
SNSP, SNSN Input Bias Current (High-Side Sensing)
SS Sourcing Current
SS Sinking Current
Error Amplifier
Full-Scale LED Current Sense Threshold (V
ISP-ISN
)
Full-Scale LED Current Sense Threshold (V
ISP-ISN
)
1/10th LED Current Sense Threshold (V
ISP-ISN
)
1/10th LED Current Sense Threshold (V
ISP-ISN
)
½ LED Current Sense Threshold (V
ISP-ISN
)
½ LED Current Sense Threshold (V
ISP-ISN
)
ISP/ISN Overcurrent Threshold
ISP/ISN Current Sense Amplifier Input Common Mode
Range (V
ISN
)
ISP/ISN Input Bias Current (Combined)
ISP/ISN Current Sense Amplifier gm
CTRL1,2 Input Bias Current
V
C
Output Impedance
V
C
Standby Input Bias Current
FB Regulation Voltage (V
FB
)
FB Amplifier g
m
FB Open LED Threshold Rising
FB Shorted LED Threshold Falling
FB Input Bias Current
C/10 Inhibit for
OPENLED
Assertion (V
ISP-ISN
)
PWM = 5V (Active), ISP = 48V
PWM = 0V (Standby), ISP = 48V
V
ISP-ISN
= 250mV, ISP = 48V
CTRL = 0V
0.9V≤ V
C
≤ 1.5V
PWM = 0V
ISP = ISN = 48V, 0V
FB = V
FB
, ISP = ISN = 48V
OPENLED
Falling, ISP Tied to ISN
SHORTLED
Falling
FB = 1V
ISN = 0V, 48V
12
l
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
l
MIN
l
TYP
41
1
0.1
MAX
2.5
43.5
1
13
500
UNITS
V
V
V
μA
μA
µA
mA
V
%/V
mV
mV
mV
Rising V
IN
Falling Hysteresis
EN/UVLO = 0V
EN/UVLO = 1.15V
R
T
= 82.5k, FB = 1.5V, PWM = 0V
PWM = 0V
0µA ≤ I
VREF
≤ 250µA
2.5V ≤ V
IN
≤ 38.5V
SNSN = 0V, 24V
SNSN = 24V
V
SNSP–SNSN
> 15mV
Combined Current Out of Pin, SNSP = SNSN = 0V
Combined Current into Pin, SNSP = SNSN = 24V
SS = 0V
SS = 2V
CTRL ≥ 1.2V, ISP = 48V
CTRL ≥ 1.2V, ISN = GND (Ground Sensing)
CTRL = 0.2V, ISP = 48V
CTRL = 0.2V, ISN = GND (Ground Sensing)
CTRL = 0.6V, ISP = 48V
CTRL = 0.6V, ISN = GND (Ground Sensing)
ISP = 48V
38.5
3
l
l
l
1.96
72
3
2
0.006
80
7
2.5
2.04
88
10
Current Sense Zero Cross Detect Threshold, V
SNSP–SNSN
SNSN = 24V, Falling
2
22
125
28
2.8
l
l
l
l
l
l
V
μA
μA
μA
μA
240
232
18
10
118
110
0
249
245
22.5
21
122
120
600
257
255
27
29
126
130
60
mV
mV
mV
mV
mV
mV
mV
V
µA
µA
µS
nA
MΩ
850
0
120
30
11
–20
1.225
V
FB–
60mV
1.25
500
V
FB–
50mV
300
200
25
1
20
1.275
V
FB–
40mV
350
39
nA
V
µS
V
mV
nA
mV
Rev 0
For more information
www.analog.com
3
LT3762
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 24V; CTRL1, CTRL2, PWM = 2V; SW, SSFM = 0V;
INTV
CC
, BOOST, DIM = 8V unless otherwise noted.
PARAMETER
FB Overvoltage Threshold Rising
V
C
Current Mode Gain (∆V
VC
/ ∆V
SNSP-SNSN
)
Oscillator
Switching Frequency (f
SWITCH
)
Switching Frequency Modulation
SSFM Input Disable Threshold
SSFM Pin Sink/Source Current
SSFM Peak-to-Peak Triangle Amplitude
MOSFET Gate Drivers
BG Minimum On Time
BG Minimum Off Time
TG Minimum On Time (Note 5)
BG Drive On Voltage
BG Drive Off Voltage
TG Drive On Voltage
TG Drive Off Voltage
TG, BG Drive Rise Time
TG, BG Drive Fall Time
PWMTG Driver Output Rise Time
PWMTG Driver Output Fall Time
PWMTG On Voltage (V
ISP
– V
PWMTG
)
PWMTG Off Voltage (V
ISP
– V
PWMTG
)
BOOST UVLO
Internal Power Supply
INTVcc Regulation Voltage
INTVcc Undervoltage Lockout Threshold
INTVcc Line Regulation (∆V
INTVCC
/ ∆V
IN
)
Logic Inputs/Outputs
EN/UVLO Threshold Voltage Falling
EN/UVLO Rising Hysteresis
EN/UVLO Input Low Voltage
EN/UVLO Pin Bias Current Low
OPENLED
Output Low
SHORTLED
Output Low
OPENLED
Pin Bias Current High
I
VIN
Drops Below 1µA
EN/UVLO = 1.15V
I
OPENLED
= 500µA
I
SHORTLED
= 500µA
OPENLED
= 1.30V
l
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
PWMTG rising
l
MIN
V
FB
+
55mV
TYP
V
FB
+
65mV
4
MAX
V
FB
+
75mV
UNITS
V
V/V
R
T
= 82.5kΩ
R
T
= 19.6kΩ
R
T
= 6.65kΩ
V
SSFM
= 2V
V
SSFM
= 1V, 2V
l
l
l
90
340
980
105
400
1080
–30
125
460
1240
0.95
kHz
%f
SWITCH
V
µA
V
ns
ns
ns
V
0.1
V
V
0.1
V
ns
ns
ns
ns
8
0.3
V
V
V
7.7
5.5
V
V
V
%/V
1.245
0.4
V
mV
V
µA
mV
mV
nA
2.3
300
300
100
12
1
230
150
130
V
INTVCC
–125mV
V
INTVCC
SW = 0V
SW = 0V
C
TG
= C
BG
= 2.7nF
C
TG
= C
BG
= 2,7nF
CL = 300pF
CL = 300pF
PWM = 2V
PWM = 0V
V
BOOST
– V
SW
V
BOOST
–125mV
V
BOOST
20
20
50
100
7
0
4.2
7.3
5.1
7.5
5.3
0.4
0.002
1.185
1.220
6
1.4
2
200
200
10
Falling INTVcc
Rising Hysteresis
2.5V < V
IN
< 38.5V
l
Rev 0
4
For more information
www.analog.com
LT3762
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 24V; CTRL1, CTRL2, PWM = 2V; SW, SSFM = 0V;
INTV
CC
, BOOST, DIM = 8V unless otherwise noted.
PARAMETER
SHORTLED
Pin Bias Current High
EN/UVLO Pin Bias Current High
PWM Pin Signal Generator
PWM Falling Threshold
PWM Threshold Hysteresis (V
PWMHYS
)
PWM Pull-Up Current (I
PWMUP
)
DIM Input Current
PWM Signal Generator Duty Ratio (Note 6)
DIM = 4V
DIM = 4V
DIM = 3.1V, PWM = 0V (100% Duty Cycle)
DIM = 5V
DIM = 0V
DIM = 1.19V
DIM = 1.42V
DIM = 1.76V
DIM = 2.1V
RisingDIM
Falling hysteresis
PWM = 82nF to GND, DIM = 0.75V, 2.5V
l
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
SHORTLED
= 1.30V
EN/UVLO = 1.30V
MIN
TYP
10
10
MAX
100
100
1.35
0.6
1
UNITS
nA
nA
V
V
µA
µA
%
%
%
%
%
V
mV
Hz
1.25
0.35
1.3
0.43
5
0.22
3.7
7
17
37
2.9
570
0.32
5
10
25
50
3.0
25
800
0.4
6.8
13
33
58
3.1
1050
DIM Input Internal PWM Disable Threshold
PWM Signal Generator Frequency
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
Do not apply a positive or negative voltage or current source to
these pins, otherwise, permanent damage may occur.
Note 3:
The LT3762E is guaranteed to meet specified performance from
0ºC to 125ºC. Specifications over the –40ºC to 125ºC operating junction
temperature range are assured by design, characterization and correlation
with statistical process controls. The LT3762I is guaranteed to meet
performance specifications over the –40ºC to 125ºC operating junction
temperature range. The LT3762H is guaranteed over the full –40ºC to
150ºC operating junction temperature range. High junction temperatures
degrade operating lifetimes. Operating lifetime is derated at junction
temperatures greater than 125ºC.
Note 4:
The LT3762 includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed the maximum operating junction temperature
when overtemperature protection is active. Continuous operation above
the specified maximum junction temperature may impair device reliability.
Note 5:
Guaranteed by design. A TG pulse will be generated only if the BG
off-time is greater than 310ns (typ). See TG Synchronous Driver under
Duty Cycle Considerations in the Applications Information section.
Note 6:
PWM Signal Generator Duty Ratio is calculated by:
Duty = I
PWMUP
/ (I
PWMUP
+ I
PWMDN
).
Note 7:
For operation at T
j
< 125°C, the absolute maximum voltage
at V
IN
, EN/UVLO, SNSP, SNSN, and SW pins is 38.5V for continuous
operation and 60V for up to one second nonrepetitive transients. For
operation at Tj > 125°C, the absolute maximum voltage at V
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