(Note 2).................................................. –40°C to 125°C
Max Junction Temperature.................................... 125°C
Storage Temperature Range
TSSOP ............................................... –65°C to 150°C
UFD.................................................... –65°C to 125°C
PIN CONFIGURATION
TOP VIEW
SHDN
PWM3
PWM2
PWM1
V
REF
CTRL3
CTRL2
CTRL1
FADJ
1
2
3
4
5
6
7
8
9
GND
29
28 V
IN
PWM2
27 TG3
26 ISN3
25 ISP3
24 SW3
23 SW2
22 ISN2
21 ISP2
20 TG2
19 SW1
18 ISN1
17 ISP1
16 TG1
15 OVP1
PWM1 1
V
REF
2
CTRL3 3
CTRL2 4
CTRL1 5
FADJ 6
V
C3
7
V
C2
8
9 10 11 12 13 14
OVP3
OVP2
OVP1
TG1
ISN1
V
C1
GND
29
TOP VIEW
PWM3
SHDN
ISN3
22 ISP3
21 SW3
20 SW2
19 ISP2
18 ISN2
17 TG2
16 SW1
15 ISP1
TG3
V
IN
28 27 26 25 24 23
V
C3
10
V
C2
11
V
C1
12
OVP3 13
OVP2 14
FE PACKAGE
28-LEAD PLASTIC TSSOP
T
JMAX
= 125°C,
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
T
JMAX
= 125°C,
θ
JA
= 34°C/W,
θ
JC
= 2.7°C/W
EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT3492EFE#PBF
LT3492IFE#PBF
LT3492EUFD#PBF
LT3492IUFD#PBF
TAPE AND REEL
LT3492EFE#TRPBF
LT3492IFE#TRPBF
LT3492EUFD#TRPBF
LT3492IUFD#TRPBF
PART MARKING*
LT3492FE
LT3492FE
3492
3492
PACKAGE DESCRIPTION
28-Lead Plastic TSSOP
28-Lead Plastic TSSOP
28-Lead (4mm
×
5mm) Plastic QFN
28-Lead (4mm
×
5mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
*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/
3492f
2
LT3492
ELECTRICAL CHARACTERISTICS
PARAMETER
V
IN
Operation Voltage
V
IN
Undervoltage Lockout
Full-Scale LED Current Sense Voltage
One-Tenth Scale LED Current Sense Voltage
ISPn/ISNn Operating Voltage
V
REF
Output Voltage
V
REF
Line Regulation
Quiescent Current in Shutdown
Quiescent Current Idle
Quiescent Current Active (Not Switching)
Switching Frequency
I
REF
= 200μA, Current Out of Pin
3V ≤ V
IN
≤ 40V, I
REF
= 10μA
SHDN
= 0V
PWM1-PWM3 = 0V
V
C1
-V
C3
= 0V
FADJ = 1.5V
FADJ = 0.5V
FADJ = 0.1V
FADJ = 1.5V (2.1MHz)
FADJ = 0.5V (1.3MHz)
FADJ = 0.1V (330kHz)
Current Out of Pin, CTRL1-3 = 0.1V
Current Out of Pin, FADJ = 0.1V
Current Out of Pin, OVP1-3 = 0.1V
0.95
PWM1-3 = 0V
ISP1-3 = 48V
ISP1-3 = 48V
(Note 3)
I
SW
= 500mA (Note 3)
SHDN
= 0V, SW = 5V
180
PWM1-3 = 0V
SHDN
= 0V
600
–20
1800
1000
280
73
80
0.1
6
11
2100
1300
340
78
87
97
20
20
10
1
0
10
200
1000
340
2
250
1
1
1300
100
100
100
1.05
20
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 5V,
SHDN
= 5V, PWM1-3 = 5V, FADJ = 0.5V, CTRL1-3 = 1.5V,
OVP1-3 = 0V, unless otherwise noted.
CONDITIONS
(Note 4)
ISP1-3 = 48V
CTRL1-3 = 100mV, ISP1-3 = 48V
MIN
3
2.1
l
TYP
MAX
30
2.4
103
104
13
60
2.04
0.03
10
8
15
2400
1600
400
UNITS
V
V
mV
mV
mV
V
V
%/V
μA
mA
mA
kHz
kHz
kHz
%
%
%
nA
nA
nA
V
nA
MΩ
μS
mA
mV
μA
μA
μA
μA
98
96
7
2.5
1.96
100
10
2
Maximum Duty Cycle
CTRL1-3 Input Bias Current
FADJ Input Bias Current
OVP1-3 Input Bias Current
OVP1-3 Threshold
V
C1-3
Idle Input Bias Current
V
C1-3
Output Impedance
EAMP g
m
(ΔI
VC
/ΔV
CAP-LED
)
SW1-3 Current Limit
SW1-3 V
CESAT
SW1-3 Leakage Current
ISP1-3 Input Bias Current
ISP1-3, ISN1-3 Idle Input Bias Current
ISP1-3, ISN1-3 Input Bias Current in Shutdown
3492f
3
LT3492
ELECTRICAL CHARACTERISTICS
PARAMETER
SHDN
Input Low Voltage
SHDN
Input High Voltage
SHDN
Pin Current
PWM1-3 Input Low Voltage
PWM1-3 Input High Voltage
PWM1-3 Pin Current
Gate Off Voltage (ISP1-3–TG1-3)
Gate On Voltage (ISP1-3–TG1-3)
Gate Turn-On Delay
Gate Turn-Off Delay
Current Into Pin
ISP1-3 = 60V, PWM1-3 = 0V
ISP1-3 = 60V
,
C
LOAD
= 300pF ISP1-3 = 60V (Note 5)
,
C
LOAD
= 300pF ISP1-3 = 60V (Note 5)
5.5
1.2
160
0.1
6.5
110
110
210
0.3
7.5
SHDN
= 5V, Current Into Pin
1.5
65
120
0.4
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 5V,
SHDN
= 5V, PWM1-3 = 5V, FADJ = 0.5V, CTRL1-3 = 1.5V,
OVP1-3 = 0V, unless otherwise noted.
CONDITIONS
MIN
TYP
MAX
0.4
UNITS
V
V
μA
V
V
μA
V
V
ns
ns
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:
The LT3492E is guaranteed to meet performance specifications
from 0°C to 125°C junction temperature. Specifications over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT3492I is guaranteed over the full –40°C to 125°C operating junction
temperature range.
Note 3:
Current flows into pin. Current limit and switch V
CESAT
is
guaranteed by design and/or correlation to static test.
Note 4:
Absolute maximum voltage at the V
IN
and
SHDN
pins is 40V for
nonrepetitive 1 second transients, and 30V for continuous operation.
Note 5:
Gate turn-on/turn-off delay is measured from 50% level of PWM