LINER LT3464 Micropower boost converter with schottky and output disconnect in thinsot Datasheet

LT3464
Micropower Boost
Converter with Schottky and
Output Disconnect in ThinSOT™
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DESCRIPTIO
FEATURES
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The LT®3464 is a micropower step-up DC/DC converter
with integrated Schottky diode and output disconnect
packaged in an 8-lead low profile (1mm) SOT-23. The
small package size, high level of integration, and the use
of tiny SMT components yield a solution size of less than
40mm2. The LT3464 has a typical current limit of 115mA
as well as fast switching speed to allow the use of a chip
inductor and small ceramic capacitors. The internal PNP
disconnects the output load from the input during shutdown, and also provides output short-circuit protection.
An auxiliary reference input allows the user to override the
internal 1.25V feedback reference with any lower value,
allowing full control of the output voltage during operation. This device features a low 25 µA quiescent current,
which is further reduced to less than 0.5µA in shutdown.
A current limited fixed off-time control scheme conserves
operating current, resulting in high efficiency over a broad
range of operating current. The rugged 36V switch and
output disconnect circuitry allow outputs up to 34V to be
easily generated in a simple boost topology.
Tiny Solution Size
Low Quiescent Current
• 25µA in Active Mode
• 0.5µA in Shutdown Mode
Internal 115mA, 36V Switch
Integrated Schottky Diode
Integrated PNP Output Disconnect with
Short-Circuit Protection
Internal Reference Override Pin
16V at 8mA from 3.6V Input
12V at 20mA from 5V Input
Input Range: 2.3V to 10V
High Output Voltage: Up to 34V
Low Profile (1mm) SOT-23 Package
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APPLICATIO S
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OEL Panel Bias
LCD Bias
Handheld Computers
Battery Backup
Digital Cameras
Cellular Phones
, LTC and LT are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technolgy Corporation
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TYPICAL APPLICATIO
Efficiency
22µH
VIN
90
80
SW
VOUT
16V
OUT
1µF
0.22µF
CTRL
LT3464
CAP
0.33µF
SHDN
3.48M
FB
GND
294k
3464 TA01a
VIN = 8.4V
VIN = 4.2V
EFFICIENCY (%)
VIN
2.3V TO 10V
70
60
50
40
30
0.01
0.1
1
10
LOAD CURRENT (mA)
100
3464 TA01b
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LT3464
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ABSOLUTE
AXI U RATI GS
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PACKAGE/ORDER I FOR ATIO
(Note 1)
VIN, SHDN, CTRL Voltage ........................................ 10V
OUT, CAP Voltage .................................................... 36V
SW Voltage .............................................................. 36V
FB Voltage ................................................................. 6V
Maximum Junction Temperature .......................... 125°C
Operating Temperature Range (Note 2) .. – 40°C to 85°C
Storage Temperature Range ..................–65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
TOP VIEW
CTRL 1
FB 2
OUT 3
GND 4
8 SHDN
7 VIN
6 SW
5 CAP
LT3464ETS8
TS8 PART MARKING
TS8 PACKAGE
8-LEAD PLASTIC SOT-23
LTG2
TJMAX = 125°C, θJA = 140°C/W, θJC = 85°C/W
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 = 3.6V, unless otherwise noted. (Note 2)
PARAMETER
CONDITIONS
MIN
Minimum Input Voltage
Quiescent Current
Not Switching
VSHDN = 0.2V
FB Comparator Trip Voltage
VFB Falling, VCTRL = 3.6V
●
1.215
FB Comparator Hysteresis
TYP
MAX
UNITS
2.0
2.3
V
25
0.01
36
0.5
µA
µA
1.250
1.275
V
10
mV
FB Pin Bias Current
VFB = 1.25V, VCTRL = 3.6V
3
30
nA
FB Voltage Line Regulation
2.3V < VIN < 10V
0.05
0.1
%/V
Switch Off Time
VCAP-VIN = 5V
VCAP-VIN = 0V
250
1.0
Switch Leakage Current
VSW = 36V
0.02
1
µA
Switch VCESAT
ISW = 80mA
190
300
mV
115
140
mA
●
Switch Current Limit
85
ns
µs
Schottky Forward Voltage
ISCHOTTKY = 110mA
600
750
mV
Schottky Reverse Leakage
VCAP-SW = 36V
1
10
µA
PNP Disconnect VCAP-OUT
IOUT = 200µA
IOUT = 10mA
100
190
PNP Disconnect Q Current
IOUT = 0, VCAP = 36V (Note 3)
1.5
5
µA
PNP Disconnect Leakage
SHDN = 0.2, VCAP = 10V, VOUT = 0V
0.1
5
µA
45
75
mA
5
10
µA
PNP Disconnect Current Limit
VCAP = 10V, VOUT = 0V
SHDN Pin Current
VSHDN = 3.6V
25
SHDN Input Voltage High
mV
mV
2.3
V
SHDN Input Voltage Low
CTRL Pin Bias Current
VCTRL = 0.5V, VFB = 1V
CTRL to FB Offset
VCTRL = 0.5V (Note 4)
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LT3464E is 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.
●
0.2
V
6
80
nA
2
7
mV
Note 3: Current consumed by Disconnect PNP when there is no load on
the OUT pin.
Note 4: This figure is computed according to ((VFB falling + VFB rising)/2)
–VCONTROL.
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LT3464
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TYPICAL PERFOR A CE CHARACTERISTICS
Switch Off-Time, VCAP – VIN = 5V
Switch Current Limit
220
140
400
200
120
350
180
160
140
120
100
SWITCH OFF-TIME (ns)
SWITCH CURRENT (mA)
SWITCH VOLTAGE (mV)
Switch Saturation Voltage
ISW = 80mA
80
60
40
20
100
–50
–25
0
25
50
TEMPERATURE (°C)
75
–25
0
25
50
TEMPERATURE (°C)
75
3464 G01
Minimum Switch On-Time
60
50
40
30
20
75
250
1.1
1.0
0.9
0.8
0.7
IOUT = 10mA
200
150
IOUT = 200µA
100
50
0.5
–50
100
–25
0
25
50
TEMPERATURE (°C)
75
0
–50
100
–25
0
25
50
TEMPERATURE (°C)
100
Output Disconnect Voltage Drop
Output Disconnect Current Limit
2.0
75
3464 G06
3464 G05
3464 G04
Output Disconnect Quiescent
Current
100
Output Disconnect Voltage Drop
0.6
10
75
0
25
50
TEMPERATURE (°C)
300
VOLTAGE DROP (mV)
SWITCH OFF-TIME (µs)
70
–25
3464 G03
1.2
80
SWITCH ON-TIME (ns)
100
Switch Off-Time, VCAP – VIN = 0V
90
0
25
50
TEMPERATURE (°C)
150
0
–50
100
1.3
–25
200
3464 G02
100
0
–50
250
50
0
–50
100
300
60
300
50
250
1.4
1.2
1.0
0.8
0.6
0.4
40
30
20
10
0.2
0
–50
VOLTAGE DROP (mV)
1.6
CURRENT LIMIT (mA)
QUIESCENT CURRENT (µA)
1.8
–25
0
25
50
TEMPERATURE (°C)
75
100
3464 G07
0
–50
200
150
100
50
–25
0
25
50
TEMPERATURE (°C)
75
100
3464 G08
0
0
10
20
COLLECTOR CURRENT (mA)
30
3464 G09
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TYPICAL PERFOR A CE CHARACTERISTICS
Schottky Forward Drop
at ID = 110mA
Schottky Reverse Leakage
Schottky Forward Voltage
800
250
20
200
16
SCHOTTKY CURRENT (mA)
VOLTAGE DROP (mV)
700
650
600
550
500
450
400
LEAKAGE CURRENT (µA)
750
150
100
50
VCAP – SW = 36V
12
8
4
350
300
–50
–25
0
25
50
TEMPERATURE (°C)
75
0
200
100
300
400
500
600
700
FORWARD VOLTAGE (mV)
0
–50
800
30
12
16
18
16
14
12
10
–50
–25
0
25
50
TEMPERATURE (°C)
75
14
10
QUIESCENT CURRENT (nA)
SHUTDOWN PIN CURRENT (µA)
QUIESCENT CURRENT (µA)
20
8
6
4
2
–25
0
25
50
TEMPERATURE (°C)
75
Quiescent Current in
Regulation with No Load
8
6
4
0
–50
100
–25
0
25
50
TEMPERATURE (°C)
75
100
3464 G14
FB Pin Voltage
SHDN Pin Threshold Voltage
70
1.30
3.0
2.8
60
1.28
2.6
50
40
30
20
2.4
FB PIN VOLTAGE (V)
SHDN PIN VOLTAGE (V)
QUIESCENT CURRENT (µA)
10
3464 G13
3464 G12
2.2
2.0
1.8
1.6
VIN = 5V
FRONT PAGE SCHEMATIC
6
8
10
14
12
VOUT (V)
1.26
1.24
1.22
1.4
10
0
12
2
0
–50
100
100
Quiescent Current in
Shutdown Mode
28
22
75
3464 G20
Shutdown Pin Current
VSHDN = 3.6V
Quiescent Current
24
0
25
50
TEMPERATURE (°C)
3464 G11
3464 G10
26
–25
1.2
16
18
20
3464 G18
1.0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
3464 G15
1.20
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
3464 G16
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TYPICAL PERFOR A CE CHARACTERISTICS
FB Pin Voltage vs
CTRL Pin Voltage
FB and CTRL Pin
Bias Currents
1.50
8
7
1.00
0.75
0.50
10
CTRL PIN
6
HYSTERESIS (mV)
BIAS CURRENT (nA)
1.25
FB PIN VOLTAGE (V)
FB Pin Hysteresis
12
5
4
FEEDBACK PIN
3
8
6
4
2
0.25
0
2
1
0
0.25
0.5 0.75 1.0 1.25 1.5
CONTROL PIN VOLTAGE (V)
1.75
0
–50
–25
0
25
50
TEMPERATURE (°C)
3464 G17
75
100
3464 G18
0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
3464 G19
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PI FU CTIO S
CTRL (Pin 1): Internal Reference Override Pin. This allows
the FB voltage to be externally set between 0V and 1.25V.
Tie this pin to above 1.5V (V IN for example) to use the
internal 1.25V reference.
 R2 
VOUT = VCTRL  + 1
 R1 
when VCTRL is less than 1.25V (see Figure 4)
FB (Pin 2): Feedback Pin. The LT3464 regulates its feedback pin to 1.25V if the internal reference is used or to
VCTRL if the CTRL pin is between 0V and 1.25V. Connect
the feedback resistor divider tap to this pin. Set the output
voltage by selecting R1 and R2 (see Figure 4).
V

R2 = R1 OUT – 1
 VREF 
GND (Pin 4): Ground. Tie this pin directly to the ground
plane.
CAP (Pin 5): PNP Emitter and Schottky Cathode. This pin
connects to the output capacitor, and optionally to the
external phase-lead capacitor.
SW (Pin 6): Switch Pin and Schottky Anode. This is the
collector of the internal NPN power switch. Minimize the
metal trace area connected to the pin to minimize EMI.
VIN (Pin 7): Input Supply Pin: Bypass this pin with a
capacitor located as close to the device as possible.
SHDN (Pin 8): Shutdown Pin. This pin is used to put the
device in shutdown mode. Tie the pin low to shut down the
LT3464. Tie high for normal operation See the electrical
specifications for the required voltages.
OUT (Pin 3): PNP Collector. This is the output of the
Output Disconnect circuit. Bypass this pin with at least a
0.1µF capacitor connected to the CAP pin or to ground.
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LT3464
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BLOCK DIAGRA
VIN
SW
CAP
OUT
7
6
5
3
DELAY
CPL
FB
CTRL
2
1
+
–
–
S
Q
R
Q
OUT
ANTI
SAT
+
1.25V
OUT
12mV
–
SHDN 8
0.1Ω
VREF
4
GND
3464 BD
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OPERATIO
The LT3464 uses a constant off-time control scheme in
conjunction with Burst Mode ® operation to provide high
efficiency over a wide range of output current. Operation
can best be understood by studying the Block Diagram.
When the FB pin voltage is lower than the 1.25V reference,
the hysteretic comparator enables the power section,
causing the chip to start switching, thus charging the
output capacitor. When the output voltage increases
enough to overcome the hysteresis, the feedback comparator shuts off the power section leaving only low power
circuitry running until the output voltage falls again. This
cycle repeats, keeping the output voltage within a small
window. The switching action is as follows: The switch
turns on, and current through it starts to ramp up until the
point where the current limit is reached, at which point the
switch turns off for a fixed amount of time. While the
switch is off the inductor is delivering current to the load.
When the off time expires, the switch turns on again until
the current limit is reached, and the cycle repeats.
This chip includes an internal power Schottky diode and a
PNP transistor for output disconnect. The PNP transistor
disconnects the load from the input during shutdown. The
PNP control circuitry is designed to keep the PNP out of
saturation across a wide range of current, to keep quiescent current to a minimum and to provide current limiting
to protect the chip during short-circuit conditions.
Burst Mode is a registered a trademark of Linear Technolgy Corporation.
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LT3464
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SWITCHI G TI E WAVEFOR S
Operating Waveforms
Start up Waveforms
IL
0.1A/DIV
IL
0.1A/DIV
VOUT
50mV/DIV
VOUT
10V/DIV
VIN = 5V
VOUT = 20V
ILOAD = 1mA
L = 22µH
50µs/DIV
5µs/DIV
Shutdown Waveforms
SHDN
5V/DIV
VIN = 5V
CAP PIN VOLTAGE
VOUT: THE OUTPUT DISCONNECT
ALLOWS VOUT TO BE AT
GROUND DURING SHUTDOWN
GND
1ms/DIV
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APPLICATIO S I FOR ATIO
in discontinuous mode. If the left hand side of inequality 1
evaluates to less than Ot FF, then use Equation 3 to calculate
maximum output current. Otherwise, use Equation 2.
Choosing an Inductor
The low current limit and fast switching of the LT3464
allow the use of very small surface mount inductors. The
minimum inductor size that may be used in a given
application depends on required efficiency and output
current. Some inductors that work with the LT3464 are
listed in Table 1, although there are many other manufacturers and devices that can be used. Consult each manufacturer for more detailed information and for their entire
selection of related parts. Many different sizes and shapes
are available.
This inequality is true when the LT3464 is operating in
discontinuous mode.
LILIM
< tOFF
(VOUT – VIN + VF )
Use this equation to calculate the maximum output current
when the LT3464 is operating in continuous mode.
Table 1. Recommended Inductors
IOUT (CM) =
PART NUMBER
µH
DCR
(Ω)
CURRENT
(mA)
MANUFACTURER
LQH32CN680K53
LQH32CN470K53
LQH32CN220K53
68
47
22
2.2
1.3
0.71
130
170
250
Murata
814-237-1431
www.murata.com
ELJPC220KF
ELJPA470KF
22
47
4.0
2.25
160
135
Panasonic
714-373-7334
www.panasonic.com
CMD4D11-47
47
2.2
180
Sumida
847-956-0666
www.Sumida.com
LB2016-220
LEM2520-220
LEM2520-330
LEMC2520-220
LEMC2520-330
LEMF2520-220
LEMC3225-680
LEMC3225-101
22
22
33
22
33
22
68
100
1.0
5.5
7.1
2.7
4.8
1.2
3.3
4.3
105
125
110
160
120
105
120
100
(INEQUALITY 1)
(2LILIM + tOFF (VIN – VOUT – VF ))(VIN – VCESAT )
2L(VOUT – VCESAT + VF )
(2)
Use this equation to calculate the maximum output current
when the LT3464 is operating in discontinuous mode.
IOUT (DCM) =
2
LILIM (VIN – VCESAT )
(3)
2(LILIM + VIN tOFF – tOFF VCESAT )(– VIN + VOUT + VF )
Taiyo Yuden
408-573-4150
www.t-yuden.com
Where VF is the Schottky forward voltage,LIM
I is the switch
current limit, tOFF is the switch off time, and VCESAT is the
switch saturation voltage. See the Electrical Specifications.
Figures 1 through 3 show the worst-case maximum output
current as given by Equations 2 and 3 using 20% inductor
The following set of formulas can be used to calculate
derating and worst-case LT3464 specifications. Also note
maximum output current given V IN, VOUT and L values.
that for some applications the maximum output current is
Inequality 1 is used to determine if the LT3464 is operating limited to 25mA by the output disconnect circuitry.
25
25
15.0
L = 47µH
20
L = 47µH
IOUT (mA)
IOUT (mA)
L = 22µH
10.0
L = 10µH
7.5
5.0
15
L = 10µH
10
0
10
15
20
25
30
35
3464 F01
Figure 1. Maximum Output Current
VIN = 3.6V
15
L = 22µH
L = 10µH
10
5
L = 4.7µH
L = 4.7µH
L = 4.7µH
VOUT (V)
8
L = 22µH
5
2.5
0
20
L = 47µH
12.5
IOUT (mA)
17.5
10
15
0
20
25
VOUT (V)
30
35
3464 F02
Figure 2. Maximum Output Current
VIN = 5V
15
20
25
VOUT (V)
30
35
3464 F03
Figure 3. Maximum Output Current
VIN = 8.4V
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APPLICATIO S I FOR ATIO
user to select between using the built-in reference, and
supplying an external reference voltage. The voltage at the
The small size and low ESR of ceramic capacitors makes
CTRL pin can be adjusted while the chip is operating to
them suitable for LT3464 applications. X5R and X7R types
alter the output voltage of the LT3464 for purposes such
are recommended because they retain their capacitance
as display dimming or contrast adjustment. To use the
over wider voltage and temperature ranges than other
internal 1.25V reference, the CTRL pin must be held higher
types such as Y5V or Z5U. A 1 µF input capacitor and a
than 1.5V, which can be done by tying it to VIN. When the
0.22µF to 0.47µF output capacitor are sufficient for most
CTRL pin is held between 0V and 1.2V the LT3464 will
LT3464 applications. Always use a capacitor with a suffiregulate the output such that the FB pin voltage is equal to
cient voltage rating. Table 2 shows a list of several capacithe CTRL pin voltage.
tor manufacturers. Consult the manufacturers for more
detailed information and for their entire selection of related To set the output voltage, select the values of R1 and R2
according to the following equation (see Figure 4).
parts.
Capacitor Selection
Table 2. Recommended Ceramic Capacitor Manufacturers
MANUFACTURER
PHONE
URL
Taiyo Yuden
408-573-4150
www.t-yuden.com
AVX
843-448-9411
www.avxcorp.com
Murata
814-237-1431
www.murata.com
Kemet
408-986-0424
www.kemet.com
V

R2 = R1 OUT – 1
 VREF 
Where VREF =1.25V if the internal reference is used, or
VREF = VCTRL if VCTRL is between 0V and 1.2V.
Choosing a Feedback Node
Output Voltage Ripple
The top of the feedback divider may be connected to the
OUT pin or to the CAP pin (see Figure 4). Regulating the
OUT pin eliminates the output offset resulting from the
voltage drop across the output disconnect. However, in
the case of a short-circuit fault at the OUT pin, the LT3464
will switch continuously because the FB pin is low. While
operating in this open-loop condition, the rising voltage at
the CAP pin is limited only by the current limit of the output
disconnect. Given worst-case parameters this voltage
may reach 25V. When the short-circuit is removed, the
The LT3464 also includes an on-chip phase-lead capacitor OUT pin will bounce up to the voltage on the CAP pin,
potentially exceeding the set output voltage until the
between the CAP pin and the FB pin to greatly reduce
capacitor voltages fall back into regulation. While this is
ripple; however, certain applications can benefit from
harmless to the LT3464, this should be considered in the
additional capacitance in parallel with the integrated capacitor, which may be added externally between the CAP context of the external circuitry if short-circuit events are
and FB pins. Typical effective values range from 4.7pF to expected.
20pF. Since the FB pin sits at a low voltage, be sure the
Regulating the CAP pin ensures that the voltage on the
chosen capacitor has a sufficient voltage rating.
OUT pin never exceeds the set output voltage after a shortcircuit event. However, this setup does not compensate
Setting Output Voltage and the
for the voltage drop across the output disconnect, resultAuxiliary Reference Input
ing in an output voltage that is slightly lower than the
voltage set by the resistor divider. The next section disThe LT3464 is equipped with both an internal 1.25V
reference and an auxiliary reference input. This allows the cusses how to compensate for this drop.
Using low ESR capacitors will help minimize the output
ripple voltage, but proper selection of the inductor and the
output capacitor also plays a big role. The LT3464 provides energy to the load in bursts by ramping up the
inductor current, then delivering that current to the load.
If too large an inductor value or too small a capacitor value
is used, the output ripple voltage will increase because the
capacitor will be slightly overcharged each burst cycle. To
reduce this effect, a larger output capacitor may be used.
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APPLICATIO S I FOR ATIO
300
6
7
6
SW
VIN
SW
OUT
CTRL
LT3464 CAP
8
SHDN
FB
GND
4
3
5
VOUT
R2
1
OUT
CTRL
LT3464 CAP
8
2
3
VOUT
5
R2
SHDN
FB
R1
250
GND
VCAP-OUT (SAT)
1
7
VIN
200
150
100
2
R1
4
50
0
3464 F01
0
5
10
15
20
25
COLLECTOR CURRENT (mA)
30
3464 F02
Figure 4. Feedback Connection Using the CAP Pin and the OUT Pin
Output Disconnect Considerations
The LT3464 is equipped with an output disconnect that
isolates the load from the input during shutdown. See the
Operation section for a functional diagram. The output
disconnect uses a pass PNP coupled with circuitry that
varies the base current such that the transistor is consistently at the edge of saturation, thus yielding the best
compromise between VCE(SAT) and low quiescent current.
To remain stable, this circuit requires a bypass capacitor
connected between the OUT pin and the CAP pin or
between the OUT pin and ground. A ceramic capacitor with
a value of at least 0.1µF is a good choice.
The PNP V CE(SAT) varies with load current as shown in
Figure 5. This voltage drop (VDROP) can be accounted for
when using the CAP pin as the feedback node by setting
the output voltage according to the following formula:
V
+ VDROP 
R2 = R1 OUT
– 1
VREF


Figure 5: Output Disconnect Voltage Drop (VDROP) vs Current
indefinite short, but care must be taken to avoid exceeding
the maximum junction temperature.
Inrush Current
When VIN is stepped from ground to operating voltage
while the output capacitor is discharged, an inrush current
will flow through the inductor and integrated Schottky
diode into the output capacitor. Conditions that increase
inrush current include a larger more abrupt voltage step at
VIN, a larger output capacitor tied to the CAP pin, and an
inductor with a low saturation current.
While the internal diode is designed to handle such events,
the inrush current should not be allowed to exceed 1 amp.
For circuits that use output capacitor values within the
recommended range and have input voltages of less than
5V, inrush current remains low, posing no hazard to
the device. In cases where there are large steps at V IN
(more than 5V) and/or a large capacitor is used at the CAP
pin, inrush current should be measured to ensure safe
operation.
In addition, the disconnect circuit has a built in current
limit of 25mA (minimum) to protect the chip during shortcircuit. This feature allows the LT3464 to tolerate an
3464f
10
LT3464
U
W
U U
APPLICATIO S I FOR ATIO
pin has sharp rising and falling edges. Minimize the length
As with all switching regulators, careful attention must be and area of all traces connected to the SW pin and always
paid to the PCB board layout and component placement. use a ground plane under the switching regulator to
To maximize efficiency, switch rise and fall times are made minimize interplane coupling. In addition, the ground
as short as possible. To prevent electromagnetic interfer- connection for the feedback resistor R1 should be tied
ence (EMI) problems, proper layout of the high frequency directly to the GND pin and not shared with any other
component, ensuring a clean, noise-free connection. Recswitching path is essential. The voltage signal of the SW
ommended component placement is shown in Figure 6.
Board Layout Considerations
GND
VIN
GND
VOUT
VIAS TO GROUND PLANE
VIA TO CONTROL
VIA TO SHDN
3464 F07
Figure 6. Recommended Layout
3464f
11
LT3464
U
TYPICAL APPLICATIO S
15V Output Converter with Output Disconnect
L1
22µH
VIN
2.3V TO 10V
C1
1µF
1
7
6
VIN
SW
OUT
CTRL
LT3464
8
CAP
SHDN
FB
3
5
2
VOUT
15V
C3
0.22µF
C2
0.22µF
VIN (V)
IOUT (mA)
3.6
7.0
5.0
10.0
8.4
19.0
VIN (V)
IOUT (mA)
3.6
3.5
5.0
4.5
8.4
7.5
R2
3.32M
R1
301k
GND
4
C1: TAIYO YUDEN LMK107 BJ105MA-T
C2: TAIYO YUDEN EMK107 BJ224MA-T
C3: TAIYO YUDEN EMK107 BJ224MA-T
L1: MURATA LQH32CN220K
3464 TA02
34V Output Converter with Output Disconnect
L1
47µH
VIN
2.3V TO 10V
C1
1µF
1
7
6
VIN
SW
OUT
CTRL
LT3464
8
CAP
SHDN
FB
3
5
2
VOUT
34V
C3
0.22µF
C2
0.33µF
R2
2.61M
R1
100k
GND
4
C1: TAIYO YUDEN LMK107 BJ105MA-T
C2: TAIYO YUDEN GMK212 BJ334MG-T
C3: TAIYO YUDEN UMK212 BJ224MG-T
L1: MURATA LQH32CN470K
3464 TA03
20V Output Converter with Output Disconnect Using an 0805
Inductor and 0603 Capacitors
L1
10µH
VIN
2.3V TO 10V
C1
1µF
1
7
6
VIN
SW
OUT
CTRL
LT3464
8
CAP
SHDN
FB
3
5
2
VOUT
20V
C3
0.1µF
C2
0.1µF
R2
4.53M
R1
301k
GND
4
C1: TAIYO YUDEN LMK107 BJ105MA-T
C2: TAIYO YUDEN TMK107 BJ104MA-T
C3: TAIYO YUDEN TMK107 BJ104MA-T
L1: TAIYO YUDEN LB 2012T100MR
VIN (V)
IOUT (mA)
3.6
3.0
5.0
4.0
8.4
6.0
3464 TA04
3464f
12
LT3464
U
TYPICAL APPLICATIO S
20V Output Converter with Output Disconnect
L1
47µH
VIN
2.3V TO 10V
C1
1µF
1
7
6
VIN
SW
OUT
CTRL
LT3464
8
CAP
SHDN
FB
3
VOUT
20V
C3
0.22µF
5
C2
0.33µF
2
R2
4.53M
R1
301k
GND
4
VIN (V)
IOUT (mA)
3.6
6.0
5.0
9.0
8.4
16.5
VIN (V)
IOUT (mA)
3.6
5.0
3464 TA05
C1: TAIYO YUDEN LMK107 BJ105MA-T
C2: TAIYO YUDEN GMK212 BJ334MG-T
C3: TAIYO YUDEN UMK212 BJ224MG
L1: MURATA LQH32CN470K
20V Output Converter with Soft Start
L1
22µH
VIN
2.3V TO 10V
OFF ON
C4
1µF
8
R1
300k
7
6
VIN
SW
OUT
SHDN
LT3464
1
C4
0.1µF
CAP
CTRL
FB
3
5
2
VOUT
20V
C3
0.22µF
C2
0.33µF
R2
4.53M
R1
301k
GND
4
C1: TAIYO YUDEN LMK107 BJ105MA-T
C2: TAIYO YUDEN GMK212 BJ334MG-T
C3: TAIYO YUDEN EMK107 BJ224MA-T
L1: MURATA LQH32CN220K
5.0
6.5
8.4
11.0
3464 TA06
3464f
13
LT3464
U
TYPICAL APPLICATIO S
8V Output Converter with Output Disconnect
L1
22µH
VIN
2.3V TO 7V
6
7
VIN
C4
1µF
8
SW
SHDN
LT3464
1
3
OUT
5
CAP
CTRL
C2
2.2µF
2
FB
VOUT
8V
C3
0.47µF
R2
1.62M
C4
20pF
VIN (V)
IOUT (mA)
3.6
13.5
5.0
20
R1
301k
GND
4
3464 TA07
C1: TAIYO YUDEN CE LMK107 BJ105MA-T
C2: TAIYO YUDEN CE LMK212 BJ225MG-T
C3: TAIYO YUDEN CE LMK107 BJ474MA-T
L1: MURATA LQH32CN220K
±20V Dual Output Converter with Output Disconnect
L1
47µH
VIN
2.3V TO 10V
C1
1µF
SW
OUT
CTRL
LT3464
8
D2
6
7
VIN
1
C5
D1
0.33µF
–VOUT I
= 2.5mA AT VIN = 3.6V
–20V OUT
C4
0.33µF
CAP
SHDN
FB
3
5
2
VOUT
20V
C3
0.22µF
C2
0.33µF
IOUT = 2.5mA AT VIN = 3.6V
R2
4.53M
R1
301k
GND
4
3464 TA08
C1: TAIYO YUDEN LMK107 BJ105MA-T
C2, C4, C5: TAIYO YUDEN GMK212 BJ334MG-T
C3: TAIYO YUDEN UMK212 BJ224MG-T
L1: MURATA LQH32CN470K
D1, D2: CENTRAL CMDSH-3
3464f
14
LT3464
U
PACKAGE DESCRIPTIO
TS8 Package
8-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1637)
0.52
MAX
2.90 BSC
(NOTE 4)
0.65
REF
1.22 REF
1.4 MIN
3.85 MAX 2.62 REF
2.80 BSC
1.50 – 1.75
(NOTE 4)
PIN ONE ID
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
0.22 – 0.36
8 PLCS (NOTE 3)
0.65 BSC
0.80 – 0.90
0.20 BSC
0.01 – 0.10
1.00 MAX
DATUM ‘A’
0.30 – 0.50 REF
0.09 – 0.20
(NOTE 3)
1.95 BSC
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
TS8 TSOT-23 0802
3464f
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LT3464
U
TYPICAL APPLICATIO S
20V Output Converter with Variable Output Voltage
and Shutdown
VIN
2.3V TO 10V
L1
22µH
C1
1µF
1
DAC
7
6
VIN
SW
OUT
CTRL
LT3464
8
µC
CAP
SHDN
FB
3
5
2
VOUT
20V
C3
0.22µF
C2
0.33µF
R2
4.53M
R1
301k
GND
4
VIN (V)
IOUT (mA)
3.6
5.0
5.0
6.5
8.4
11.0
3464 TA09
C1: TAIYO YUDEN LMK107 BJ105MA-T
C2: TAIYO YUDEN GMK212 BJ334MG-T
C3: TAIYO YUDEN GMK212 BJ224MG-T
L1: MURATA LQH32CN220K
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1613
550mA (ISW), 1.4MHz, High Efficiency
Step-Up DC/DC Converter
VIN = 0.9V to 10V, VOUT(MAX) = 34V, IQ = 3mA, ISD = <1µA,
ThinSOT Package
LT1615/
LT1615-1
300mA/80mA (ISW), Constant Off-Time,
High Efficiency Step-Up DC/DC Converter
VIN = 1.2V to 15V, VOUT(MAX) = 34V, IQ = 20µA, ISD = <1µA,
ThinSOT Package
LT1618
Constant Current, Constant Voltage, 1.4MHz,
High Efficiency Boost Regulator
VIN = 1.6V to 18V, VOUT(MAX) = 34V, IQ = 1.8mA, ISD = <1µA,
MS Package, Up to 6 White LEDs
LT1932
Constant Current, 1.2MHz, High Efficiency
White LED Boost Regulator
VIN = 1V to 10V, VOUT(MAX) = 34V, IQ = 1.2mA, ISD = <1µA,
ThinSOT Package, Up to 8 White LEDs
LT1937
Constant Current, 1.2MHz, High Efficiency
White LED Boost Regulator
VIN = 2.5V to 10V, VOUT(MAX) = 34V, IQ = 1.9mA, ISD = <1µA,
SC-70, ThinSOT Packages, Up to 4 White LEDs
LT1944
Dual Output 350mA (ISW), Constant Off-Time,
High Efficiency Step-Up DC/DC Converter
VIN = 1.2V to 15V, VOUT(MAX) = 34V, IQ = 20µA, ISD = <1µA,
MS Package
LT1944-1
Dual Output 150mA (ISW), Constant Off-Time,
High Efficiency Step-Up DC/DC Converter
VIN = 1.2V to 15V, VOUT(MAX) = 34V, IQ = 20µA, ISD = <1µA,
MS Package
LT1945
Dual Output, ±350mA (ISW), Constant Off-Time,
High Efficiency Step-Up DC/DC Converter
VIN = 1.2V to 15V, VOUT(MAX) = ±34V, IQ = 20µA, ISD = <1µA,
MS Package
LTC3200/
LTC3200-5
Low Noise, 2MHz, Regulated Charge Pump
White LED Driver
VIN = 2.7V to 4.5V, IQ = 8mA, ISD = <1µA,
MS, ThinSOT Packages, Up to 6 White LEDs
LTC3201
Low Noise, 1.7MHz, Regulated Charge Pump
White LED Driver
VIN = 2.7V to 4.5V, IQ = 6.5mA, ISD = <1µA,
MS Package, Up to 6 White LEDs
LTC3202
Low Noise, 1.5MHz, Regulated Charge Pump
White LED Driver
VIN = 2.7V to 4.5V, IQ = 5mA, ISD = <1µA,
MS Package, Up to 8 White LEDs
LTC3400/
LTC3400B
600mA (ISW), 1.2MHz, Synchronous
Step-Up DC/DC Converter
VIN = 0.85V to 5V, VOUT(MAX) = 5V, IQ = 19µA/300µA, ISD = <1µA,
ThinSOT Package
LTC3401
1A (ISW), 3MHz, Synchronous
Step-Up DC/DC Converter
VIN = 0.5V to 5V, VOUT(MAX) = 6V, IQ = 38µA, ISD = <1µA,
MS Package
LTC3402
2A (ISW), 3MHz, Synchronous
Step-Up DC/DC Converter
VIN = 0.5V to 5V, VOUT(MAX) = 6V, IQ = 38µA, ISD = <1µA,
MS Package
3464f
16
Linear Technology Corporation
LT/TP 0204 1K • PRINTED IN USA
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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