LT3500EDD (Note 2) .......................... –40°C to 125°C
LT3500IDD (Note 2) ........................... –40°C to 125°C
LT3500HDD (Note 2).......................... –40°C to 150°C
LT3500EMSE (Note 2)........................ –40°C to 125°C
LT3500IMSE (Note 3) ........................ –40°C to 125°C
LT3500HMSE (Note 2) ....................... –40°C to 150°C
Storage Temperature Range................... –65°C to 150°C
PIN CONFIGURATION
TOP VIEW
V
IN
SHDN
SS
PG
V
C
R
T
/SYNC
1
2
3
4
5
6
13
12 SW
11 BST
10 LDRV
9 LFB
8 FB
7
PG
NC1
V
IN
SHDN
SS
PG
V
C
R
T
/SYNC
NC8
1
2
3
4
5
6
7
8
TOP VIEW
16
15
14
13
12
11
10
9
NC16
SW
BST
LDRV
LFB
FB
PG
NC9
17
DD PACKAGE
12-LEAD (3mm
×
3mm) PLASTIC DFN
θ
JA
= 45°C/W,
θ
JC(PAD)
= 10°C/W
EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB
MSE PACKAGE
16-LEAD PLASTIC MSE
θ
JA
= 45°C/W,
θ
JC(PAD)
= 10°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LT3500EDD#PBF
LT3500IDD#PBF
LT3500HDD#PBF
LT3500EMSE#PBF
LT3500IMSE#PBF
LT3500HMSE#PBF
TAPE AND REEL
LT3500EDD#TRPBF
LT3500IDD#TRPBF
LT3500HDD#TRPBF
LT3500EMSE#TRPBF
LT3500IMSE#TRPBF
LT3500HMSE#TRPBF
PART MARKING*
LCRN
LCRN
LDCY
3500
3500
3500
PACKAGE DESCRIPTION
12-Lead (3mm
×
3mm) Plastic DFN
12-Lead (3mm
×
3mm) Plastic DFN
12-Lead (3mm
×
3mm) Plastic DFN
16-Lead Plastic MSE
16-Lead Plastic MSE
16-Lead Plastic MSE
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 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/
3500fc
2
LT3500
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
J
= 25°C. V
VIN
= 15V, V
RT/SYNC
= 2V, unless otherwise specified.
PARAMETER
SHDN Threshold
SHDN Source Current
SHDN Current Hysterisis
Minimum Input Voltage (Note 3)
Supply Shutdown Current
Supply Quiescent Current
FB Voltage
FB Bias Current
Error Amplifier g
m
Error Amplifier Source Current
Error Amplifier Sink Current
Error Amplifier High Clamp
Error Amplifier Switching Threshold
SS Source Current
SS Sink Current
SS POR Sink Current (Note 4)
SS POR Threshold
SS to FB Offset (V
SS
– V
FB
)
PG/PG Leakage
PG/PG Threshold (Rising)
PG/PG Hysteresis (Falling)
PG Sink Current
PG
Sink Current
R
T
/SYNC Reference Voltage
Switching Frequency
V
VC
= V
FS
, V
SS
= 0.4V
V
FB
= 0.9V, V
PG
/V
PG
= 40V
V
PG
= 0.4V
V
PG
= 0.4V
V
PG
= 0.4V, V
FB
= 0.7V
V
PG
= 0.4V, V
FB
= 0.9V
V
FB
= 0.9V, R
RT/SYNC
= 15k
R
RT/SYNC
= 90.9k
R
RT/SYNC
= 90.9k
R
RT/SYNC
= 15k
V
FB
= 0.7V, R
RT/SYNC
= 90.9k
V
FB
= 0.7V, R
RT/SYNC
= 90.9k
V
SW
= 0V
I
SW
= 2A, V
BST
= 18V, V
FB
= 0.7V
V
BST
= 18V, V
FB
= 0.7V
V
BST
= 18V, V
FB
= 0.7V
I
SW
= 2A, V
BST
= 20V, V
FB
= 0.7V
I
SW
= 2A, V
FB
= 0.7V
l
l
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
MIN
l
TYP
760
2.5
2
2.4
12
2.5
MAX
780
3.5
3.25
2.8
30
3.5
0.816
0.824
150
350
20
22
2.2
1.0
3.75
900
800
150
120
1
0.730
40
750
1100
0.975
550
625
2.8
2500
UNITS
mV
μA
μA
V
μA
mA
V
V
nA
μmho
μA
μA
V
V
μA
μA
μA
mV
mV
μA
V
mV
μA
μA
V
kHz
kHz
MHz
kHz
ns
ns
710
1.5
1.25
V
SHDN
= 0.62V
V
FB
= 0V
V
SHDN
= 0V
V
FB
= 0.9V
V
VC
= 1V
V
VC
= 0.8V to 1.6V, V
IN
= 3V to 40V
V
FB
= 0.8V, V
VC
= 1V
V
VC
= 1V, I
VC
= ±10μA
V
FB
= 0.6V, V
VC
= 1V
V
FB
= 1V, V
VC
= 1V
V
FB
= 0.6V
V
FB
= 0.6V
V
SS
= 0.4V, V
FB
= 0.9V
V
FB
= 0V, V
SS
= 2V
V
FB
= 0V, V
SS
= 2V, Cycle SHDN
l
l
l
l
0.784
0.776
150
12
14
1.8
0.6
2.25
300
400
50
70
0.685
20
250
500
0.75
450
425
2
250
0.8
0.8
50
250
16
18
2.0
0.8
2.75
600
600
100
100
0.1
0.708
30
500
800
0.850
500
500
2.4
140
120
1
450
SYNC Frequency Range
Minimum Switch On Time
Minimum Switch Off Time
Switch Leakage Current
Switch Saturation Voltage
Switch Peak Current DD Package
Switch Peak Current MSE Package
Boost Current
Minimum Boost Voltage (Note 5)
10
3.5
3.5
3.5
3.7
45
3
μA
mV
A
A
A
A
mA
V
2.3
2.1
2.3
2.1
20
2.8
2.8
2.9
2.9
30
2.2
3500fc
3
LT3500
ELECTRICAL CHARACTERISTICS
PARAMETER
LFB Voltage
LFB Line/Load Regulation
SS to LFB Offset (V
SS
– V
LFB
)
LFB Bias Current
LDRV Dropout (V
VIN
– V
LDRV
)
LDRV Maximum Current
CONDITIONS
V
LDRV
= V
LFB
V
VIN
= 3V to 40V, V
LDRV
= V
LFB
V
SS
= 0.8V, V
LDRV
= V
LFB
V
LFB
= 0.8V
V
LDRV
= 3V, I
LDRV
= 5mA
V
LDRV
= 0V
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
J
= 25°C. V
VIN
= 15V, V
RT/SYNC
= 2V, unless otherwise specified.
MIN
0.784
0.776
90
0.8
9
TYP
0.8
0.8
115
115
1.2
13
MAX
0.816
0.824
140
300
1.6
18
UNITS
V
V
mV
nA
V
mA
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.
Note2:
The LT3500EDD/LT3500EMSE 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 LT3500IDD/LT3500IMSE is guaranteed over the full –40°C to 125°C
operating junction temperature range. The LT3500HDD/LT3500HMSE is
guaranteed over the full –40°C to 150°C operating junction temperature
range. High junction temperatures degrade operating lifetimes. Operating
lifetime is derated at junction temperatures greater than 125°C.
Note 3:
Minimum input voltage is defined as the voltage where internal
bias lines are regulated so that the reference voltage and oscillator remain
constant. Actual minimum input voltage to maintain a regulated output
will depend upon output voltage and load current. See Applications
Information.
Note 4:
An internal power-on reset (POR) latch is set on the positive
transition of the SHDN pin through its threshold. The output of the latch
activates a current source on the SS pin which typically sinks 600μA,
discharging the SS capacitor. The latch is reset when the SS pin is driven
below the soft-start POR threshold or the SHDN pin is taken below its
threshold.
Note 5:
This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the internal power switch.
Note 6:
This IC 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 operating junction temperature may impair device