LT3465ES6 [Linear]
1.2MHz/2.4MHz White LED Step-Up Converters with Built-In Schottky in ThinSOT; 的1.2MHz / 2.4MHz是白光LED升压型转换器,具有内置肖特基采用ThinSOT型号: | LT3465ES6 |
厂家: | Linear |
描述: | 1.2MHz/2.4MHz White LED Step-Up Converters with Built-In Schottky in ThinSOT |
文件: | 总12页 (文件大小:375K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
LT3465/LT3465A
1.2MHz/2.4MHz White LED
Step-Up Converters with
Built-In Schottky in ThinSOT
U
DESCRIPTIO
FEATURES
The LT®3465/LT3465A are step-up DC/DC converters
designedtodriveuptosixLEDsinseriesfromaLi-Ioncell.
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.
■
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)
■
Automatic Soft-Start (LT3465)
■
Open LED Protection
■
High Efficiency: 81% (LT3465) 79% (LT3465A)
Typical
The LT3465 switches at 1.2MHz, allowing the use of tiny
external components. The faster LT3465A switches at
2.4MHz. Constantfrequencyswitchingresultsinlowinput
noise and a small output capacitor. Just 0.22µF is required
for 3-, 4- or 5-LED applications.
■
Requires Only 0.22µF Output Capacitor
■
Low Profile (1mm) SOT-23 Packaging
U
APPLICATIO S
■
Cellular Phones
The LT3465 and LT3465A are available in low profile
(1mm) 6-lead SOT-23 (ThinSOTTM) packages.
■
PDAs, Handheld Computers
■
Digital Cameras
, LTC and LT are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
■
MP3 Players
■
GPS Receivers
U
TYPICAL APPLICATIO
Conversion Efficiency
L1
82
22µH
V
= 3.6V
IN
80
78
76
74
72
70
68
66
64
62
60
4 LEDs
3V TO 5V
SW
V
OUT
V
IN
C1
1µF
C2
0.22µF
LT3465/
LT3465A
CTRL
GND
SHUTDOWN
AND DIMMING
CONTROL
FB
10Ω
3465A F01a
C1, C2: X5R OR X7R DIELECTRIC
L1: MURATA LQH32CN220
LT3465
LT3465A
10
0
5
15
20
Figure 1. Li-Ion Powered Driver for Four White LEDs
LED CURRENT (mA)
3465A F01b
3465af
1
LT3465/LT3465A
W W U W
U W
U
ABSOLUTE AXI U RATI GS
(Note 1)
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
Input Voltage (VIN) ................................................. 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
TOP VIEW
V
1
6 SW
OUT
GND 2
FB 3
5 V
IN
LT3465ES6
LT3465AES6
4 CTRL
S6 PACKAGE
6-LEAD PLASTIC TSOT-23
S6 PART MARKING
TJMAX = 125°C, θJA = 256°C/W IN FREE AIR
θJA = 120°C ON BOARD OVER GROUND PLANE
LTH2
LTAFT
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
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
TYP
LT3465A
TYP
PARAMETER
CONDITIONS
MIN
MAX
MIN
MAX
UNITS
V
Minimum Operating Voltage
Maximum Operating Voltage
Feedback Voltage
2.7
2.7
16
16
V
0°C ≤ T ≤ 85°C
188
10
200
35
212
100
188
10
200
35
212
100
mV
nA
A
FB Pin Bias Current
Supply Current
Not Switching
CTRL = 0V
1.9
2.0
2.6
3.2
3.3
5.0
1.9
2.0
2.6
3.2
3.3
5.0
mA
µA
Switching Frequency
Maximum Duty Cycle
Switch Current Limit
0.8
90
1.2
93
1.6
1.8
90
2.4
93
2.8
MHz
%
●
●
225
340
300
0.01
225
340
300
0.01
mA
mV
µA
Switch V
I
= 250mA
= 5V
CESAT
SW
Switch Leakage Current
V
5
5
SW
V
V
for Full LED Current
to Shut Down Chip
1.8
1.8
V
CTRL
CTRL
50
50
mV
CTRL Pin Bias Current
48
40
60
60
50
75
72
60
90
48
40
60
60
50
75
72
60
90
µA
µA
µA
T = 85°C
T = –40°C
A
A
Soft-Start Time
600
0.7
µs
V
Schottky Forward Drop
Schottky Leakage Current
I = 150mA
0.7
D
V = 30V
R
4
4
µA
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.
3465af
2
LT3465/LT3465A
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Shutdown Quiescent Current
(CTRL = 0V)
Switch Saturation Voltage (VCESAT
)
Schottky Forward Voltage Drop
450
400
350
300
250
200
150
100
50
300
250
200
150
100
50
30
27
24
21
18
15
12
9
T
= 25°C
T
= 25°C
T
= 25°C
A
A
A
6
3
0
0
0
0
400
600
800
1000 1200
4
6
10
(V)
12
0
50 100 150
350
200
2
14
16
200 250 300
8
V
SCHOTTKY FORWARD DROP (mV)
SWITCH CURRENT (mA)
IN
3465A G02
3465A G01
3465A G03
VFB vs VCTRL
Open-Circuit Output Clamp Voltage
Input Current in Output Open Circuit
5
4
3
2
1
0
250
200
150
100
50
35
30
T
= 25°C
T
= 25°C
T
A
= 25°C
A
A
25
20
15
10
5
0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0
2
10
INPUT VOLTAGE (V)
14
16
2
4
6
8
12
INPUT VOLTAGE (V)
CONTROL VOLTAGE (V)
3465A G04
3465A G06
3465A G05
Switching Waveforms (LT3465)
Switching Frequency
Switching Waveforms (LT3465A)
3.0
2.5
2.0
1.5
1.0
0.5
0
VSW
VSW
10V/DIV
10V/DIV
LT3465A
IL
IL
100mA/DIV
50mA/DIV
VOUT
100mV/DIV
VOUT
50mV/DIV
LT3465
V
IN = 3.6V
200ns/DIV
3465A G07a
V
IN = 3.6V
100ns/DIV
3465A G07b
4 LEDs
4 LEDs
20mA, 22µH
20mA, 22µH
50
TEMPERATURE (°C)
100
–50
0
4365A G08
3465af
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LT3465/LT3465A
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Quiescent Current (CTRL = 3V)
Switching Current Limit
Feedback Voltage
3.0
2.5
210
208
206
204
202
200
198
196
194
192
190
400
350
300
250
2.0
1.5
200
150
1.0
0.5
0
100
50
0
–50°C
–50°C
25°C
100°C
25°C
100°C
0
5
10
(V)
15
20
20
40
DUTY CYCLE (%)
80
–50
70
90
0
60
100
–30 –10 10
30
TEMPERATURE (°C)
50
V
IN
3465A G10
3465A G11
3465A G09
VIN = 3.6V, 4 LEDs
Schottky Leakage Current
85
80
75
70
65
60
8
7
6
5
LT3465
LT3465A
20mA
V
= 25
R
V
= 16
= 10
R
V
R
15mA
4
3
10mA
2
1
0
50
100
0
50
–50
0
–50
100
TEMPERATURE (°C)
TEMPERATURE (°C)
3465A G12
3465A G13
U
U
U
PI FU CTIO S
VOUT (Pin 1): Output Pin. Connect to output capacitor and
LEDs. Minimize trace between this pin and output capaci-
tor to reduce EMI.
CTRL(Pin4):DimmingControlandShutdownPin.Ground
this pin to shut down the device. When VCTRL is greater
thanabout1.8V,full-scaleLEDcurrentisgenerated.When
VCTRL is less than 1V, LED current is reduced.
GND (Pin 2): Ground Pin. Connect directly to local ground
plane.
VIN (Pin 5): Input Supply Pin. Must be locally bypassed
with a 1µF X5R or X7R type ceramic capacitor.
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:
SW (Pin 6): Switch Pin. Connect inductor here.
200mV
RFB
VCTRL
5 •RFB
ILED
ILED
≈
≈
When VCTRL > 1.8V
When VCTRL < 1V
3465af
4
LT3465/LT3465A
W
BLOCK DIAGRA
V
IN
FB
3
5
6
SW
V
OUT
1
–
+
+
COMPARATOR
A2
200mV
–
+
V
REF
A1
DRIVER
1.25V
Q1
R
Q
R
C
S
OVERVOLTAGE
PROTECT
C
C
+
–
0.2Ω
Σ
10k
RAMP
GENERATOR
CTRL
4
40k
2
GND
3465A F02
1.2MHz*
OSCILLATOR
*2.4MHz FOR LT3465A
Figure 2. LT3465 Block Diagram
W U U
U
APPLICATIO S I FOR ATIO
Operation
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
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
betweenthefeedbackvoltageandthereferencevoltageof
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
referencevoltage. TheblockdiagramfortheLT3465A(not
shown) is identical except that the oscillator frequency is
2.4MHz.
VSW
5V/DIV
IL
20mA/DIV
VOUT
10mV/DIV
VIN = 4.2V
ILED = 1.5mA
3 LEDs
0.2µs/DIV
3465A F03a
Figure 3a. Switching Waveforms (LT3465)
VSW
5V/DIV
IL
20mA/DIV
VOUT
10mV/DIV
Minimum Output Current
V
IN = 4.2V
0.1µs/DIV
3465A F03b
T
he LT3465 can drive a 3-LED string at 1.5mA LED
ILED = 0.2mA
3 LEDs
current without pulse skipping. As current is further
reduced, the device will begin skipping pulses. This will
Figure 3b. Switching Waveforms (LT3465A)
3465af
5
LT3465/LT3465A
W U U
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APPLICATIO S I FOR ATIO
85
80
75
reacheszeroduringthedischargephase. Aftertheinduc-
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 300Ω resistor across the
inductor, although this will degrade efficiency. Because
ofthehigherswitchingfrequency, theLT3465Acandrive
a 3-LED string at 0.2mA LED current without pulse
skipping. The photo in Figure 3b detials circuit operation
driving three white LEDs at a 0.2mA load. Peak inductor
current is less than 30mA.
V
= 3.6V
IN
4 LEDs
70
65
60
55
50
MURATA LQH32CN220
TAIYO YUDEN LB2012B220M
TAIYO YUDEN CB2012B220
5
10
20
0
15
LED CURRENT (mA)
3465A F04b
Figure 4a. Efficiency Comparison of Different Inductors (LT3465)
Inductor Selection
80
V
= 3.6V
IN
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
recommendedformostLT3465Aapplications. Theinduc-
tor should have low core losses at 2.4MHz and low DCR.
The efficiency comparison of different inductors is shown
in figure 4b.
4 LEDs
75
70
65
60
55
50
MURATA LQH32CN220
MURATA LQH32CN100
MURATA LQH2MCN220
TOKO D312-220
TOKO D312-100
TAIYO YUDEN LB2012B220
5
10
20
0
15
LED CURRENT (mA)
3465A F04b
Table 1. Recommended Inductors
Figure 4b. Efficiency Comparison of Different Inductors (LT3465A)
PART
NUMBER
CURRENT RATING
(mA)
DCR (Ω)
MANUFACTURER
Capacitor Selection
LQH32CN220
LQH2MCN220
0.71
2.4
250
185
Murata
814-237-1431
www.murata.com
The small size of ceramic capacitors makes them ideal for
LT3465andLT3465Aapplications.X5RandX7Rtypesare
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.
ELJPC220KF
4.0
0.53
1.7
160
350
75
Panasonic
714-373-7334
www.panasonic.com
CDRH3D16-220
LB2012B220M
LEM2520-220
Sumida
847-956-0666
www.sumida.com
Taiyo Yuden
408-573-4150
www.t-yuden.com
Table 2. Recommended Ceramic Capacitor Manufacturers
MANUFACTURER
Taiyo Yuden
Murata
PHONE
URL
408-573-4150
814-237-1431
408-986-0424
www.t-yuden.com
www.murata.com
www.kemet.com
5.5
125
Taiyo Yuden
408-573-4150
www.t-yuden.com
Kemet
3465af
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LT3465/LT3465A
W U U
APPLICATIO S I FOR ATIO
U
Soft-Start (LT3465)
Table 3 gives inrush peak currents for some component
selections.
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.
Table 3. Inrush Peak Current
V
(V)
r (Ω)
0.5
L (µH)
22
C (µF)
0.22
1
I (A)
IN
P
5
0.38
0.70
0.26
0.60
5
3.6
5
0.5
22
0.5
22
0.22
1
IIN 50mA/DIV
VOUT 5V/DIV
0.5
33
VFB 100mV/DIV
CTRL 5V/DIV
LED Current and Dimming Control
The LED current is controlled by the feedback resistor (R1
in Figure 1) and the feedback reference voltage.
VIN = 3.6V
4 LEDs, 20mA
L = 22µH
200µs/DIV
3465 F05
ILED = VFB/RFB
C = 0.22µF
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
dimmingcontrolwhenCTRLvoltageisbetween200mVto
1.5V. In order to have accurate LED current, precision
resistors are preferred (1% is recommended). The for-
mula and table for RFB selection are shown below.
Figure 5. Start-Up Waveforms
Inrush Current
The LT3465 and LT3465A have a built-in Schottky diode.
When supply voltage is applied to the VIN pin, the voltage
difference between VIN and VOUT generates inrush current
flowing from input through the inductor and the Schottky
diode to charge the output capacitor to VIN. 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:
RFB = 200mV/ILED-Full
(1)
Table 4. RFB Resistor Value Selection
FULL I
(mA)
R1 (Ω)
40.0
LED
5
10
15
20
20.0
13.3
V – 0.6
α
ω
α
ω
α
IN
IP =
• exp – • arctan
• sin arctan
10.0
L • ω
r + 1.5
2 •L
ω
The filtered PWM signal can be considered as an adjust-
able DC voltage. It can be used to adjust the CTRL voltage
source in dimming control. The circuit is shown in Fig-
ure 6. The cornerfrequencyofR1C1 should be lower than
the freqency of the PWM signal. R1 needs to be much
smallerthantheinternalimpedanceintheCTRLpin,which
is 50kΩ.
α =
2
r + 1.5
4 •L2
1
–
(
)
ω =
L •C
where L is the inductance, r is the resistance of the
inductor and C is the output capacitance. For low DCR
inductors, which is usually the case for this application,
the peak inrush current can be simplified as follows:
LT3465/
R1
5k
LT3465A
CTRL
PWM
C1
100nF
3465A F06
V – 0.6
L • ω
α π
• exp – •
IN
IP =
Figure 6. Dimming Control Using a Filtered PWM Signal
ω 2
3465af
7
LT3465/LT3465A
W U U
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APPLICATIO S I FOR ATIO
Dimming Using Direct PWM (LT3465A)
minimize the input current. VOUT and input current during
output open circuit are shown in the Typical Performance
Characteristics.
Unlike the LT3465, the LT3465A does not have internal
soft-start.Althoughtheinputcurrentishigherduringstart-
up, the absence of soft-start allows the CTRL pin to be
directly driven with a PWM signal for dimming. A zero
percentdutycyclesetstheLEDcurrenttozero,while100%
duty cycle sets it to full current. Average LED current
increases proportionally with the duty cycle of the PWM
signal.PWMfrequencyshouldbebetween1kHzand10kHz
for best performance. The PWM signal should be at least
1.8V in magnitude; lower voltage will lower the feedback
voltage as shown in Equation 1. Waveforms are shown for
a 1kHz PWM and 10kHz PWM signal in Figures 7a and 7b
respectively.
Board Layout Consideration
As with all switching regulators, careful attention must be
paid to the PCB board layout and component placement.
Tomaximizeefficiency, switchriseandfalltimesaremade
as short as possible. To prevent electromagnetic interfer-
ence (EMI) problems, proper layout of the high frequency
switching path is essential. Place COUT next to the VOUT
pin. 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, ensuringaclean, noise-freeconnection. Rec-
ommended component placement is shown in Figure 8.
LT3465A
PWM
CTRL
GND
C
OUT
L
1
2
3
6
5
4
FB
C
IN
100mV/DIV
V
IN
R
FB
CTRL
CTRL
2V/DIV
3465A F08
Figure 8. Recommended Component Placement
200µs/DIV (1kHz)
3465A F07a
Figure 7a.
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.
FB
100mV/DIV
CTRL
2V/DIV
20µs/DIV (10kHz)
3465A F07b
IIN
200mV/DIV
Figure 7b.
Open-Circuit Protection
FB
200mV/DIV
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 VOUT is clamped at 30V. The LT3465 and
LT3465A will then switch at a very low frequency to
CTRL
2V/DIV
50µs/DIV
3465A F09
Figure 9.
3465af
8
LT3465/LT3465A
U
TYPICAL APPLICATIO S
Li-Ion to Two White LEDs
L1
22µH
85
V
= 3.6V
IN
2 LEDs
3V TO 5V
80
75
SW
V
OUT
V
IN
70
65
60
55
50
C
C
OUT
IN
1µF
LT3465/
LT3465A
CTRL
GND
1µF
FB
R1
4Ω
3465A TA01a
C
C
: TAIYO YUDEN JMK107BJ105
IN
LT3465
LT3465A
: AVX 0603ZD105
OUT
L1: MURATA LQH32CN220
0
10
20
30
40
50
LED CURRENT (mA)
3465A TA01b
Li-Ion to Three White LEDs
L1
22µH
85
V
= 3.6V
IN
3V TO 5V
3 LEDs
80
75
SW
V
OUT
V
IN
C
IN
1µF
C
70
65
60
55
50
OUT
LT3465/
LT3465A
CTRL
GND
0.22µF
FB
R1
10Ω
3465A TA02a
C
C
: TAIYO YUDEN JMK107BJ105
IN
: AVX 0603YD224
LT3465
OUT
L1: MURATA LQH32CN220
LT3465A
0
5
10
15
20
LED CURRENT (mA)
3465A TA02b
3465af
9
LT3465/LT3465A
U
TYPICAL APPLICATIO S
Li-Ion to Five White LEDs
L1
22µH
3V TO 5V
SW
V
OUT
V
IN
C
C
OUT
IN
LT3465/
LT3465A
CTRL
GND
1µF
0.22µF
FB
R1
10Ω
3465A TA03a
C
C
: TAIYO YUDEN JMK107BJ105
IN
: TAIYO YUDEN GMK212BJ224
OUT
L1: MURATA LQH32CN220
85
80
75
70
65
60
55
50
V
= 3.6V
IN
5 LEDs
LT3465
LT3465A
0
5
10
15
20
LED CURRENT (mA)
3465A TA03b
3465af
10
LT3465/LT3465A
U
PACKAGE DESCRIPTIO
S6 Package
6-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1636)
2.90 BSC
(NOTE 4)
0.62
MAX
0.95
REF
1.22 REF
1.4 MIN
1.50 – 1.75
2.80 BSC
3.85 MAX 2.62 REF
(NOTE 4)
PIN ONE ID
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
0.30 – 0.45
6 PLCS (NOTE 3)
0.95 BSC
0.80 – 0.90
0.20 BSC
DATUM ‘A’
0.01 – 0.10
1.00 MAX
0.30 – 0.50 REF
1.90 BSC
0.09 – 0.20
(NOTE 3)
S6 TSOT-23 0302
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
3465af
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
11
LT3465/LT3465A
U
TYPICAL APPLICATIO
Li-Ion to Six White LEDs
L1
85
80
75
70
65
60
55
50
47µH/22µH
V
= 3.6V
IN
3V TO 5V
6 LEDs
SW
V
OUT
V
IN
C
C
OUT
IN
LT3465/
LT3465A
CTRL
GND
1µF
0.47µF
FB
R1
10Ω
3465A TA04a
C
C
: TAIYO YUDEN JMK107BJ105
: TAIYO YUDEN GMK212BJ474
L1: MURATA LQH32CN470 (LT3465)
L1: MURATA LQH32CN220 (LT3465A)
IN
LT3465
LT3465A
OUT
0
5
10
15
20
LED CURRENT (mA)
3465A TA04b
RELATED PARTS
PART NUMBER DESCRIPTION
COMMENTS
LT1618
LT1932
LT1937
Constant Current, Constant Voltage, 1.4MHz, High Efficiency Up to 16 White LEDs, V : 1.6V to 18V, V
: 34V, I : 1.8mA,
IN
OUT(MAX) Q
Boost Regulator
I
: <1µA, 10-Lead MS
SHDN
Constant Current, 1.2MHz, High Efficiency White LED
Boost Regulator
Up to 8 White LEDs, V : 1V to 10V, V
SHDN
: 34V, I : 1.2mA,
IN
OUT(MAX) Q
I
: <1µA, ThinSOT
Constant Current, 1.2MHz, High Efficiency White LED
Boost Regulator
Up to 4 White LEDs, V : 2.5V to 10V, V
SHDN
: 34V, I : 1.9mA,
OUT(MAX) Q
IN
I
: <1µA, ThinSOT, SC70
LTC®3200-5
LTC3202
Low Noise, 2MHz, Regulated Charge Pump White LED Driver Up to 6 White LEDs, V : 2.7V to 4.5V, I : 8mA, I
: <1µA, ThinSOT
SHDN
IN
Q
Low Noise, 1.5MHz, Regulated Charge Pump White LED Driver Up to 8 White LEDs, V : 2.7V to 4.5V, I : 5mA, I
: <1µA,
SHDN
IN
Q
10-Lead MS
LTC3205
Multi-Display LED Controller
92% Efficiency, V : 2.8V to 4.5V, I : 4.2mA, I : <1µA, QFN,
IN
Q
SD
Drives Main, Sub, RGB
LTC3405
LTC3405A
300mA (I ), 1.5MHz Synchronous Step-Down
95% Efficiency, V : 2.7V to 6V, V
: 0.8V, I : 20µA, I : <1µA,
SHDN
OUT
IN
OUT(MIN)
Q
DC/DC Converter
ThinSOT
LTC3406
600mA (I ), 1.5MHz Synchronous Step-Down
95% Efficiency, V : 2.5V to 5.5V, V
: 0.6V, I : 20µA,
Q
OUT
IN
OUT(MIN)
OUT(MIN)
OUT(MIN)
OUT(MIN)
OUT(MIN)
LTC3406B
DC/DC Converter
I
: <1µA, ThinSOT
SHDN
LTC3407
LTC3411
LTC3412
Dual 600mA (I ), 1.5MHz Synchronous Step-Down
95% Efficiency, V : 2.5V to 5.5V, V
: 0.6V, I : 40µA,
Q
OUT
IN
DC/DC Converters
I
: <1µA, MS10E, DFN
SHDN
1.25A (I ), 4MHz Synchronous Step-Down DC/DC Converter 95% Efficiency, V : 2.5V to 5.5V, V
: 0.8V, I : 60µA,
Q
OUT
IN
I
: <1µA, MS10, DFN
SHDN
2.5A (I ), 4MHz Synchronous Step-Down DC/DC Converter 95% Efficiency, V : 2.5V to 5.5V, V
: 0.8V, I : 60µA,
Q
OUT
IN
I
: <1µA, TSSOP16E
SHDN
LTC3440/
LTC3441
600mA/1.2A (I ), 2MHz/1MHz Synchronous Buck-Boost
95% Efficiency, V : 2.5V to 5.5V, V
: 2.5V, I : 25µA,
Q
OUT
IN
DC/DC Converter
I
: <1µA, 10-Lead MS
SHDN
LT3466
Full Function White LED Step-Up Converter with
Built-In Schottkys
Drives Up to 20 LEDs, Independent Step-Up Converters,
V : 2.7µV to 24V, DFN Package
IN
3465af
LT/TP 0504 1K • PRINTED IN USA
12 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
●
●
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
LINEAR TECHNOLOGY CORPORATION 2003
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