LT3465/LT3465A
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, LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a
trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
APPLICATIO S
U
FEATURES
TYPICAL APPLICATIO
U
DESCRIPTIO
U
Inherently Matched LED Current
Drives Up to Six LEDs from a 3.6V Supply
No External Schottky Diode Required
1.2MHz Switching Frequency (LT3465)
2.4MHz Switching Frequency Above AM Broadcast
Band (LT3465A)
V
IN
Range: 2.7V to 16V
V
OUT(MAX)
= 30V
Automatic Soft-Start (LT3465)
Open LED Protection
High Efficiency: 81% (LT3465) 79% (LT3465A)
Typical
Requires Only 0.22µF Output Capacitor
Low Profile (1mm) SOT-23
1.2MHz/2.4MHz White
LED Drivers with Built-in
Schottky in ThinSOT
Cellular Phones
PDAs, Handheld Computers
Digital Cameras
MP3 Players
GPS Receivers
The LT
®
3465/LT3465A are step-up DC/DC converters
designed to drive up to six LEDs in series from a Li-Ion cell.
Series connection of the LEDs provides identical LED
currents and eliminates the need for ballast resistors.
These devices integrate the Schottky diode required exter-
nally on competing devices. Additional features include
output voltage limiting when LEDs are disconnected, one-
pin shutdown and dimming control. The LT3465 has
internal soft-start.
The LT3465 switches at 1.2MHz, allowing the use of tiny
external components. The faster LT3465A switches at
2.4MHz. Constant frequency switching results in low input
noise and a small output capacitor. Just 0.22µF is required
for 3-, 4- or 5-LED applications.
The LT3465 and LT3465A are available in the low profile
(1mm) 6-lead SOT-23 (ThinSOT
TM
) package.
Figure 1. Li-Ion Powered Driver for Four White LEDs
SW V
OUT
V
IN
LT3465/
LT3465A
CTRL
3465A F01a
10
C1
1µF
C2
0.22µF
C1, C2: X5R OR X7R DIELECTRIC
L1: MURATA LQH32CN220
L1
22µH
3V TO 5V
SHUTDOWN
AND DIMMING
CONTROL
FB
GND
LED CURRENT (mA)
0
EFFICIENCY (%)
78
80
20
3465A F01b
76
60
70
68
66
64
62
72
74
510 15
82 V
IN
= 3.6V
4 LEDs
LT3465
LT3465A
Conversion Efficiency
LT3465/LT3465A
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V
OUT
1
GND 2
TOP VIEW
S6 PACKAGE
6-LEAD PLASTIC TSOT-23
FB 3
6 SW
5 V
IN
4 CTRL
Input Voltage (V
IN
) ................................................. 16V
SW Voltage ............................................................. 36V
FB Voltage ................................................................ 2V
CTRL Voltage .......................................................... 10V
Operating Temperature Range (Note 2) .. 40°C to 85°C
Maximum Junction Temperature ......................... 125°C
Storage Temperature Range ................ 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
(Note 1)
ABSOLUTE AXI U RATI GS
WWWU
The denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 3V, VCTRL = 3V, unless otherwise noted.
LT3465 LT3465A
PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
Minimum Operating Voltage 2.7 2.7 V
Maximum Operating Voltage 16 16 V
Feedback Voltage 0°C T
A
85°C 188 200 212 188 200 212 mV
FB Pin Bias Current 10 35 100 10 35 100 nA
Supply Current Not Switching 1.9 2.6 3.3 1.9 2.6 3.3 mA
CTRL = 0V 2.0 3.2 5.0 2.0 3.2 5.0 µA
Switching Frequency 0.8 1.2 1.6 1.8 2.4 2.8 MHz
Maximum Duty Cycle 90 93 90 93 %
Switch Current Limit 225 340 225 340 mA
Switch V
CESAT
I
SW
= 250mA 300 300 mV
Switch Leakage Current V
SW
= 5V 0.01 5 0.01 5 µA
V
CTRL
for Full LED Current 1.8 1.8 V
V
CTRL
to Enable Chip 150 150 mV
V
CTRL
to Shut Down Chip 50 50 mV
CTRL Pin Bias Current 48 60 72 48 60 72 µA
T
A
= 85°C 405060405060 µA
T
A
= –40°C 607590607590 µA
Soft-Start Time 600 µs
Schottky Forward Drop I
D
= 150mA 0.7 0.7 V
Schottky Leakage Current V
R
= 30V 4 4 µA
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LT3465E/LT3465AE are guaranteed to meet performance
specifications from 0°C to 70°C. Specifications over the –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls.
T
JMAX
= 125°C, θ
JA
= 256°C/W IN FREE AIR
θ
JA
= 120°C ON BOARD OVER GROUND PLANE
ORDER PART NUMBER S6 PART MARKING
PACKAGE/ORDER I FOR ATIO
UU
W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
LT3465ES6
LT3465AES6
LTH2
LTAFT
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: http://www.linear.com/leadfree/
LT3465/LT3465A
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SCHOTTKY FORWARD DROP (mV)
0
0
SCHOTTKY FORWARD CURRENT (mA)
50
100
150
200
300
200 400 600 800
3465A G02
1000 1200
250
TA = 25°C
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Switch Saturation Voltage (VCESAT) Schottky Forward Voltage Drop
Shutdown Quiescent Current
(CTRL = 0V)
SWITCH CURRENT (mA)
0
0
SWITCH SATURATION VOLTAGE (mV)
50
150
200
250
200
450
3465A G01
100
100
50 250 300
150 350
300
350
400
TA = 25°C
V
IN
(V)
2
I
Q
(µA)
12
15
18
814
3465A G03
9
6
3
04 6 10 12
21
24
27
30
16
T
A
= 25°C
VFB vs VCTRL Open-Circuit Output Clamp Voltage
CONTROL VOLTAGE (V)
0
FEEDBACK VOLTAGE (mV)
100
150
2
3465A G04
50
00.5 11.5
250
200
T
A
= 25°C
INPUT VOLTAGE (V)
2
20
25
35
812
3465A G05
15
10
46 10 14 16
5
0
30
OUTPUT CLAMP VOLTAGE (V)
T
A
= 25°C
Input Current in Output Open Circuit
Switching Waveforms (LT3465)
INPUT VOLTAGE (V)
2 2.5
0
INPUT CURRENT (mA)
2
5
344.5
3465A G06
1
4
3
3.5 5
TA = 25°C
V
SW
10V/DIV
I
L
100mA/DIV
V
OUT
100mV/DIV
V
IN
= 3.6V 200ns/DIV 3465A G07a
4 LEDs
20mA, 22µH
TEMPERATURE (°C)
–50
4365A G08
050 100
SWITCHING FREQUENCY (MHz)
3.0
2.5
2.0
1.5
1.0
0.5
0
LT3465
LT3465A
Switching Frequency
Switching Waveforms (LT3465A)
V
SW
10V/DIV
I
L
50mA/DIV
V
OUT
50mV/DIV
V
IN
= 3.6V 100ns/DIV 3465A G07b
4 LEDs
20mA, 22µH
LT3465/LT3465A
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TYPICAL PERFOR A CE CHARACTERISTICS
UW
Quiescent Current (CTRL = 3V)
VIN (V)
0
0
IQ (mA)
0.5
1.0
1.5
2.0
2.5
3.0
5101520
3465A G10
–50°C
25°C
100°C
DUTY CYCLE (%)
0
CURRENT LIMIT (mA)
150
200
250
60 100
3465A G11
100
50
020 40 80
300
350
400
–50°C
25°C
100°C
TEMPERATURE (°C)
–50
EFFICIENCY (%)
70
75
3465A G12
65
60 050 100
85
20mA
80
10mA
15mA
LT3465
LT3465A
Switching Current Limit
VIN = 3.6V, 4 LEDs
TEMPERATURE (°C)
–50
SCHOTTKY LEAKAGE CURRENT (µA)
3
4
V
R
= 25
V
R
= 16
V
R
= 10
5
3465A G13
2
1
0050
6
7
8
100
Schottky Leakage Current
TEMPERATURE (°C)
–50
190
FEEDBACK VOLTAGE (mV)
192
196
198
200
210
204
–10 30 50
3465A G09
194
206
208
202
–30 10 70 90
Feedback Voltage
LT3465/LT3465A
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U
PI FU CTIO S
V
OUT
(Pin 1): Output Pin. Connect to output capacitor and
LEDs. Minimize trace between this pin and output capaci-
tor to reduce EMI.
GND (Pin 2): Ground Pin. Connect directly to local ground
plane.
FB (Pin 3): Feedback Pin. Reference voltage is 200mV.
Connect LEDs and a resistor at this pin. LED current is
determined by the resistance and CTRL pin voltage:
CTRL (Pin 4): Dimming Control and Shutdown Pin. Ground
this pin to shut down the device. When V
CTRL
is greater
than about 1.8V, full-scale LED current is generated.
When V
CTRL
is less than 1V, LED current is reduced.
Floating this pin places the device in shutdown mode.
V
IN
(Pin 5): Input Supply Pin. Must be locally bypassed
with a 1µF X5R or X7R type ceramic capacitor.
SW (Pin 6): Switch Pin. Connect inductor here.
IRmV mV n
mV
mV
LED FB
=
1200 26 1
200
26
•–
exp
expp
VmV
mV mV
CTRL
()
+
526
1
>for V mV
CTRL 150
LT3465/LT3465A
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BLOCK DIAGRA
W
+
+
+
RQ
S
0.2
SW
DRIVER
COMPARATOR
2
CTRL
4
6V
OUT
V
IN
3
FB
200mV
5
+
Σ
RAMP
GENERATOR
OVERVOLTAGE
PROTECT
R
C
10k
40k
C
C
1.2MHz*
OSCILLATOR *2.4MHz FOR LT3465A
GND
3465A F02
Q1
A2
A1
V
REF
1.25V
1
Figure 2. LT3465 Block Diagram
LT3465/LT3465A
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APPLICATIO S I FOR ATIO
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Operation
The LT3465 uses a constant frequency, current mode
control scheme to provide excellent line and load regula-
tion. Operation can be best understood by referring to the
block diagram in Figure 2. At the start of each oscillator
cycle, the SR latch is set, which turns on the power switch
Q1. A voltage proportional to the switch current is added
to a stabilizing ramp and the resulting sum is fed into the
positive terminal of the PWM comparator A2. When this
voltage exceeds the level at the negative input of A2, the
SR latch is reset turning off the power switch. The level at
the negative input of A2 is set by the error amplifier A1,
and is simply an amplified version of the difference
between the feedback voltage and the reference voltage of
200mV. In this manner, the error amplifier sets the
correct peak current level to keep the output in regulation.
If the error amplifier’s output increases, more current is
delivered to the output; if it decreases, less current is
delivered. The CTRL pin voltage is used to adjust the
reference voltage.
The block diagram for the LT3465A (not
shown) is identical except that the oscillator frequency
is 2.4MHz.
Minimum Output Current
T
he LT3465
can drive a 3-LED string at 1.5mA LED
current without pulse skipping. As current is further
reduced, the device will begin skipping pulses. This will
result in some low frequency ripple, although the LED
current remains regulated on an average basis down to
zero. The photo in Figure 3a details circuit operation
driving three white LEDs at a 1.5mA load. Peak inductor
current is less than 40mA and the regulator operates in
discontinuous mode, meaning the inductor current
reaches zero during the discharge phase. After the induc-
tor current reaches zero, the SW pin exhibits ringing due
to the LC tank circuit formed by the inductor in combina-
tion with switch and diode capacitance. This ringing is
not harmful; far less spectral energy is contained in the
ringing than in the switch transitions. The ringing can be
damped by application of a 300 resistor across the
inductor, although this will degrade efficiency. Because
of the higher switching frequency, the LT3465A can drive
a 3-LED string at 0.2mA LED current without pulse
V
SW
5V/DIV
I
L
20mA/DIV
V
OUT
10mV/DIV
V
IN
= 4.2V 0.2µs/DIV 3465A F03a
I
LED
= 1.5mA
3 LEDs
Figure 3b. Switching Waveforms (LT3465A)
V
SW
5V/DIV
I
L
20mA/DIV
V
OUT
10mV/DIV
V
IN
= 4.2V 0.1µs/DIV 3465A F03b
I
LED
= 0.2mA
3 LEDs
Figure 3a. Switching Waveforms (LT3465)
LT3465/LT3465A
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skipping using a 1k resistor from FB to GND. The photo
in Figure 3b details circuit operation driving three white
LEDs at a 0.2mA load. Peak inductor current is less
than 30mA.
Inductor Selection
A 22µH inductor is recommended for most LT3465 appli-
cations. Although small size and high efficiency are major
concerns, the inductor should have low core losses at
1.2MHz and low DCR (copper wire resistance). Some
inductors in this category with small size are listed in
Table 1. The efficiency comparison of different inductors
is shown in Figure 4a. A 22µH or 10µH inductor is recom-
mended for most LT3465A applications. The inductor
should have low core losses at 2.4MHz and low DCR. The
efficiency comparison of different inductors is shown in
figure 4b.
Table 1. Recommended Inductors
PART CURRENT RATING
NUMBER DCR () (mA) MANUFACTURER
LQH32CN220 0.71 250 Murata
LQH2MCN220 2.4 185 814-237-1431
www.murata.com
ELJPC220KF 4.0 160 Panasonic
714-373-7334
www.panasonic.com
CDRH3D16-220 0.53 350 Sumida
847-956-0666
www.sumida.com
LB2012B220M 1.7 75 Taiyo Yuden
408-573-4150
www.t-yuden.com
LEM2520-220 5.5 125 Taiyo Yuden
408-573-4150
www.t-yuden.com
LED CURRENT (mA)
0
70
75
15
3465A F04b
65
60
510 20
55
50
80
EFFICIENCY (%)
V
IN
= 3.6V
4 LEDs
MURATA LQH32CN220
MURATA LQH32CN100
MURATA LQH2MCN220
TOKO D312-220
TOKO D312-100
TAIYO YUDEN LB2012B220
APPLICATIO S I FOR ATIO
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Capacitor Selection
The small size of ceramic capacitors makes them ideal for
LT3465 and LT3465A applications. X5R and X7R types are
recommended because they retain their capacitance over
wider voltage and temperature ranges than other types
such as Y5V or Z5U. A 1µF input capacitor and a 0.22µF
output capacitor are sufficient for most LT3465 and
LT3465A applications.
Table 2. Recommended Ceramic Capacitor Manufacturers
MANUFACTURER PHONE URL
Taiyo Yuden 408-573-4150 www.t-yuden.com
Murata 814-237-1431 www.murata.com
Kemet 408-986-0424 www.kemet.com
LED CURRENT (mA)
0
70
75
85
15
3465A F04b
65
60
510 20
55
50
80
EFFICIENCY (%)
MURATA LQH32CN220
TAIYO YUDEN LB2012B220M
TAIYO YUDEN CB2012B220
V
IN
= 3.6V
4 LEDs
Figure 4a. Efficiency Comparison of Different Inductors (LT3465)
Figure 4b. Efficiency Comparison of Different Inductors (LT3465A)
LT3465/LT3465A
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APPLICATIO S I FOR ATIO
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inductors, which is usually the case for this application,
the peak inrush current can be simplified as follows:
IV
L
PIN
=
–.
exp
06
2ω
α
ω
π
Table 3 gives inrush peak currents for some component
selections.
Table 3. Inrush Peak Current
V
IN
(V) r ()L (µH) C (µF) I
P
(A)
5 0.5 22 0.22 0.38
5 0.5 22 1 0.70
3.6 0.5 22 0.22 0.26
5 0.5 33 1 0.60
LED Current and Dimming Control
The LED current is controlled by the feedback resistor (R1
in Figure 1) and the feedback reference voltage.
I
LED
= V
FB
/R
FB
The CTRL pin controls the feedback reference voltage as
shown in the Typical Performance Characteristics. For
CTRL higher than 1.8V, the feedback reference is 200mV,
which results in full LED current. CTRL pin can be used as
dimming control when CTRL voltage is between 200mV to
1.5V. In order to have accurate LED current, precision
resistors are preferred (1% is recommended). The for-
mula and table for R
FB
selection are shown below.
R
FB
= 200mV/I
LED-Full
(1)
Table 4. RFB Resistor Value Selection
FULL I
LED
(mA) R1 ()
5 40.0
10 20.0
15 13.3
20 10.0
The filtered PWM signal can be considered to be an
adjustable DC voltage. It can be used to adjust the CTRL
voltage source in dimming control. The circuit is shown in
Figure 6. The corner frequency of R1 and C1 should be
I
IN
50mA/DIV
V
IN
= 3.6V 200µs/DIV 3465 F05
4 LEDs, 20mA
L = 22µH
C = 0.22µF
V
OUT
5V/DIV
V
FB
100mV/DIV
CTRL 5V/DIV
Figure 5. Start-Up Waveforms
Inrush Current
The LT3465 and LT3465A have a built-in Schottky diode.
When supply voltage is applied to the V
IN
pin, the voltage
difference between V
IN
and V
OUT
generates inrush current
flowing from input through the inductor and the Schottky
diode to charge the output capacitor to V
IN
. The maximum
current the Schottky diode in the LT3465 and LT3465A
can sustain is 1A. The selection of inductor and capacitor
value should ensure the peak of the inrush current to be
below 1A. The peak inrush current can be calculated
as follows:
IV
L
r
L
LC
r
L
PIN
=
=+
=
+
()
–.
exp arctan sin arctan
.
.
06
15
2
115
4
2
2
ω
α
ω
ω
α
ω
α
α
ω
where L is the inductance, r is the resistance of the
inductor and C is the output capacitance. For low DCR
Soft-Start (LT3465)
The LT3465 has an internal soft-start circuit to limit the
input current during circuit start-up. The circuit start-up
waveforms are shown in Figure 5.
LT3465/LT3465A
10
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lower than the frequency of the PWM signal. R1 needs to
be much smaller than the internal impedance in the CTRL
pin, which is 50k. A 5k resistor is suggested.
percent duty cycle sets the LED current to zero, while
100% duty cycle sets it to full current. Average LED
current increases proportionally with the duty cycle of the
PWM signal. With the PWM signal at the CTRL pin to turn
the LT3465A on and off, the output capacitor is charged
and discharged accordingly. This capacitor charging/
discharging affects the waveform at the FB pin. For low
PWM frequencies the output capacitor charging/discharg-
ing time is a very small portion in a PWM period. The
average FB voltage increases linearly with the PWM duty
cycle. As the PWM frequency increases, the capacitor
charging/discharging has a larger effect on the linearity of
the PWM control. Waveforms for a 1kHz and 10kHz PWM
CTRL signals are shown in Figures 7a and 7b respectively.
The capacitor charging/discharging has a larger effect on
the FB waveform in the 10kHz case than that in the 1kHz
APPLICATIO S I FOR ATIO
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Figure 7a.
Figure 7b.
FB
100mV/DIV
CTRL
2V/DIV
200µs/DIV (1kHz) 3465A F07a
FB
100mV/DIV
CTRL
2V/DIV
20µs/DIV (10kHz) 3465A F07b
LT3465A
CTRL
PWM
Dimming Using Direct PWM (LT3465A)
Unlike the LT3465, the LT3465A does not have internal
soft-start. Although the input current is higher during
start-up, the absence of soft-start allows the CTRL pin to
be directly driven with a PWM signal for dimming. A zero
LT3465/
LT3465A
CTRL
3465A F06
PWM C1
100nF
R1
5k
Figure 6. Dimming Control Using a Filtered PWM Signal
LT3465/LT3465A
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CTRL PWM DUTY CYCLE (%)
0
AVERAGE FEEDBACK VOLTAGE (mV)
200
180
160
140
120
100
80
60
40
20
080
3465A F07f
20 40 60 100
4 LEDs
3 LEDs
2 LEDs
30kHz PWM
C
OUT
= 0.22µF
CTRL PWM DUTY CYCLE (%)
0
AVERAGE FEEDBACK VOLTAGE (mV)
200
180
160
140
120
100
80
60
40
20
080
3465A F07d
2010 30 50 70 90
40 60 100
30kHz
10kHz
1kHz
100Hz
10Hz
C
OUT
= 0.47µF
4 LEDs
CTRL PWM DUTY CYCLE (%)
0
AVERAGE FEEDBACK VOLTAGE (mV)
200
180
160
140
120
100
80
60
40
20
080
3465A F07c
20 40 60 100
30kHz
10kHz
1kHz
100Hz
10Hz
C
OUT
= 0.22µF
4 LEDs
CTRL PWM DUTY CYCLE (%)
0
AVERAGE FEEDBACK VOLTAGE (mV)
200
180
160
140
120
100
80
60
40
20
080
3465A F07e
20 40 60 100
4 LEDs
3 LEDs
2 LEDs
10kHz PWM
C
OUT
= 0.22µF
Figure 7e.VFB vs CTRL PWM Duty Cycle Figure 7f.VFB vs CTRL PWM Duty Cycle
APPLICATIO S I FOR ATIO
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Figure 7c. VFB vs CTRL PWM Duty Cycle Figure 7d. VFB vs CTRL PWM Duty Cycle
case. The Average FB Voltage vs PWM Duty Cycle curves
of different PWM frequencies with different output ca-
pacitors are shown in Figures 7c and 7d respectively. For
PWM frequency lower than 1kHz, the curves are almost
linear. For PWM frequency higher than 10kHz, the curves
show strong nonlinearity. Since the cause of the
nonlinearity is the output capacitor charging/discharg-
ing, the output capacitance and output voltage also affect
the nonlinearity in the high PWM frequencies. Because
smaller capacitance corresponds to shorter capacitor
charging/discharging time, the smaller output capaci-
tance has better linearity as shown in Figures 7c and 7d.
Figures 7e and 7f show the output voltage’s effect to the
curves. The PWM signal should be at least 1.8V in
magnitude; lower voltage will lower the feedback voltage
as shown in Equation 1.
LT3465/LT3465A
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APPLICATIO S I FOR ATIO
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Figure 9.
Open-Circuit Protection
The LT3465 and LT3465A have an internal open-circuit
protection circuit. In the cases of output open circuit,
when the LEDs are disconnected from the circuit or the
LEDs fail, the V
OUT
is clamped at 30V. The LT3465 and
LT3465A will then switch at a very low frequency to
minimize the input current. V
OUT
and input current during
output open circuit are shown in the Typical Performance
Characteristics.
Board Layout Consideration
As with all switching regulators, careful attention must be
paid to the PCB board layout and component placement.
To maximize efficiency, switch rise and fall times are
made as short as possible. To prevent electromagnetic
interference (EMI) problems, proper layout of the high
frequency switching path is essential. Place C
OUT
next to
the V
OUT
and GND pins. Always use a ground plane under
the switching regulator to minimize interplane coupling.
In addition, the ground connection for the feedback
resistor R1 should be tied directly to the GND pin and not
shared with any other component, ensuring a clean, noise-
free connection. Recommended component placement is
shown in Figure 8.
Start-Up Input Current (LT3465A)
As previously mentioned, the LT3465A does not have an
internal soft-start circuit. Inrush current can therefore rise
to approximately 400mA as shown in Figure 9 when
driving 4 LEDs. The LT3465 has an internal soft-start
circuit and is recommended if inrush current must be
minimized.
Figure 8. Recommended Component Placement.
1
COUT
L
RFB
2
3
6
5
4
CIN
GND
3465A F08a
VIN
CTRL
FB
200mV/DIV
CTRL
2V/DIV
50µs/DIV 3465A F09
I
IN
200mV/DIV
LT3465/LT3465A
13
3465afa
TYPICAL APPLICATIO S
U
Li-Ion to Two White LEDs
SW V
OUT
V
IN
LT3465/
LT3465A
CTRL
3465A TA01a
R1
4
C
IN
1µF
C
OUT
1µF
C
IN
: TAIYO YUDEN JMK107BJ105
C
OUT
: AVX 0603ZD105
L1: MURATA LQH32CN220
L1
22µH
3V TO 5V
FB
GND
LED CURRENT (mA)
0
EFFICIENCY (%)
75
80
85
40
3465A TA01b
70
65
60
55
50 10 20 30 50
V
IN
= 3.6V
2 LEDs
LT3465
LT3465A
SW V
OUT
V
IN
LT3465/
LT3465A
CTRL
3465A TA02a
R1
10
C
IN
1µF
C
OUT
0.22µF
L1
22µH
3V TO 5V
FB
GND
C
IN
: TAIYO YUDEN JMK107BJ105
C
OUT
: AVX 0603YD224
L1: MURATA LQH32CN220
Li-Ion to Three White LEDs
LED CURRENT (mA)
0
EFFICIENCY (%)
75
80
85
3465A TA02b
70
65
60
55
50 510 15 20
VIN = 3.6V
3 LEDs
LT3465
LT3465A
LT3465/LT3465A
14
3465afa
TYPICAL APPLICATIO
U
Li-Ion to Five White LEDs
SW V
OUT
V
IN
LT3465/
LT3465A
CTRL
3465A TA03a
R1
10
C
IN
1µF
C
OUT
0.22µF
L1
22µH
3V TO 5V
FB
GND
C
IN
: TAIYO YUDEN JMK107BJ105
C
OUT
: TAIYO YUDEN GMK212BJ224
L1: MURATA LQH32CN220
LED CURRENT (mA)
0
EFFICIENCY (%)
75
85
80
3465A TA03b
70
65
60
55
50 510 15 20
V
IN
= 3.6V
5 LEDs
LT3465
LT3465A
LT3465/LT3465A
15
3465afa
U
PACKAGE DESCRIPTIO
S6 Package
6-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1636)
1.50 – 1.75
(NOTE 4)
2.80 BSC
0.30 – 0.45
6 PLCS (NOTE 3)
DATUM ‘A’
0.09 – 0.20
(NOTE 3)
S6 TSOT-23 0302
2.90 BSC
(NOTE 4)
0.95 BSC
1.90 BSC
0.80 – 0.90
1.00 MAX 0.01 – 0.10
0.20 BSC
0.30 – 0.50 REF
PIN ONE ID
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
3.85 MAX
0.62
MAX
0.95
REF
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
1.4 MIN
2.62 REF
1.22 REF
LT3465/LT3465A
16
3465afa
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
FAX: (408) 434-0507
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2005
LT/LT 0805 REV A • PRINTED IN USA
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Q
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SHDN
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TYPICAL APPLICATIO
U
Li-Ion to Six White LEDs
SW V
OUT
V
IN
LT3465/
LT3465A
CTRL
3465A TA04a
R1
10
C
IN
1µF
C
OUT
0.47µF
L1
47µH/22µH
3V TO 5V
FB
GND
C
IN
: TAIYO YUDEN JMK107BJ105
C
OUT
: TAIYO YUDEN GMK212BJ474
L1: MURATA LQH32CN470 (LT3465)
L1: MURATA LQH32CN220 (LT3465A)
LED CURRENT (mA)
0
EFFICIENCY (%)
75
85
80
3465A TA04b
70
65
60
55
50 510 15 20
V
IN
= 3.6V
6 LEDs
LT3465
LT3465A