Datasheet LTC3400BES6, LTC3400ES6 Datasheet (Linear Technology)

FEATURES

■

Up to 92% Efficiency

■

Generates 3.3V at 100mA from a Single AA Cell

■

Low Start-Up Voltage: 0.85V

■

1.2MHz Fixed Frequency Switching

■

Internal Synchronous Rectifier

■

2.5V to 5V Output Range

■

Automatic Burst Mode® Operation (LTC3400)

■

Continuous Switching at Light Loads (LTC3400B)

■

Logic Controlled Shutdown (<1µA)

■

Antiringing Control Minimizes EMI

■

Tiny External Components

■

Low Profile (1mm) ThinSOTTM Package

U

APPLICATIO S

■

Pagers

■

MP3 Players

■

Digital Cameras

■

LCD Bias Supplies

■

Handheld Instruments

■

Wireless Handsets

■

GPS Receivers

LTC3400/LTC3400B

600mA, 1.2MHz Micropower

Synchronous Boost Converter

in ThinSOT

U

DESCRIPTIO

The LTC®3400/LTC3400B are synchronous, fixed fre­quency, step-up DC/DC converters delivering high effi­ciency in a 6-lead ThinSOT package. Capable of supplying

3.3V at 100mA from a single AA cell input, the devices
contain an internal NMOS switch and PMOS synchronous
rectifier.

A switching frequency of 1.2MHz minimizes solution
footprint by allowing the use of tiny, low profile inductors
and ceramic capacitors. The current mode PWM design is
internally compensated, reducing external parts count.
The LTC3400 features automatic shifting to power saving
Burst Mode operation at light loads, while the LTC3400B
features continuous switching at light loads. Antiringing
control circuitry reduces EMI concerns by damping the
inductor in discontinuous mode, and the devices feature
low shutdown current of under 1µA.

Both devices are available in the low profile (1mm) ThinSOT
package.

, LTC, LT and Burst Mode are registered trademarks of Linear Technology Corporation.

ThinSOT is a trademark of Linear Technology Corporation.

TYPICAL APPLICATIO

L1

4.7µH

+

SINGLE
AA CELL

C1, C2: TAIYO-YUDEN X5R EMK316BJ475ML
L1: COILCRAFT DO160C-472

Figure 1. Single Cell to 3.3V Synchronous Boost Converter

C1

4.7µF

OFF

ON

6

4

V

IN

LTC3400

SHDN

SW

GND

U

Efficiency

100

1

V

C2

4.7µF

3400 F01

OUT

3.3V
100mA

5

V

OUT

2

R1

1.02M
1%

3

FB

R2
604k
1%

90

80

70

EFFICIENCY (%)

60

FIGURE 1 CIRCUIT

50

WITH OPTIONAL SCHOTTKY DIODE
(SEE APPLICATIONS INFORMATION)

40

0.1 10 100 1000

VIN = 2.4V

VIN = 1.5V

1

LOAD CURRENT (mA)

3400 F01a

3400f

1

LTC3400/LTC3400B

PACKAGE/ORDER I FOR ATIO

UU

W

WWWU

ABSOLUTE AXI U RATI GS

(Note 1)

VIN Voltage ................................................. –0.3V to 6V

SW Voltage ................................................. –0.3V to 6V

SHDN, FB Voltage ....................................... –0.3V to 6V

V

........................................................... –0.3V to 6V

OUT

Operating Temperature Range (Note 2) .. – 30°C to 85°C

Storage Temperature Range ................... – 65°C to 125°

Lead Temperature (Soldering, 10 sec)..................300°C

ORDER PART

TOP VIEW

SW 1

GND 2

FB 3

S6 PACKAGE

6-LEAD PLASTIC SOT-23

T

= 125°C, θJA = 256°C/W

JMAX

6 V

IN

5 V

OUT

4 SHDN

NUMBER

LTC3400ES6
LTC3400BES6

S6 PART MARKING

LTWK
LTUN

Consult LTC Marketing for parts specified with wider operating temperature ranges.

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at TA = 25°C. VIN = 1.2V, V

PARAMETER CONDITIONS MIN TYP MAX UNITS

Minimum Start-Up Voltage I
Minimum Operating Voltage SHDN = VIN (Note 4) 0.5 0.65 V
Output Voltage Adjust Range 2.5 5 V
Feedback Voltage ● 1.192 1.23 1.268 V
Feedback Input Current VFB = 1.25V (Note 3) 1 nA
Quiescent Current (Burst Mode Operation) VFB = 1.4V (Note 5), LTC3400 Only 19 30 µA
Quiescent Current (Shutdown) V
Quiescent Current (Active) Measured On V
NMOS Switch Leakage VSW = 5V 0.1 5 µA
PMOS Switch Leakage VSW = 0V 0.1 5 µA
NMOS Switch On Resistance V

PMOS Switch On Resistance V

NMOS Current Limit 600 850 mA
Burst Mode Operation Current Threshold LTC3400 Only (Note 3) 3 mA
Current Limit Delay to Output (Note 3) 40 ns
Max Duty Cycle VFB = 1.15V ● 80 87 %
Switching Frequency 0.95 1.2 1.5 MHz

SHDN Input High 1V
SHDN Input Low 0.35 V
SHDN Input Current V

LOAD

SHDN

OUT

V

OUT

OUT

V

OUT

SHDN

The ● denotes the specifications which apply over the full operating

= 3.3V, unless otherwise specified.

OUT

= 1mA 0.85 1 V

= 0V, Not Including Switch Leakage 0.01 1 µA

OUT

= 3.3V 0.35 Ω
= 5V 0.20 Ω

= 3.3V 0.45 Ω
= 5V 0.30 Ω

● 0.85 1.2 1.5 MHz

= 5.5V 0.01 1 µA

300 500 µA

Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.

Note 2: The LTC3400E/LTC3400BE are guaranteed to meet performance
specifications from 0°C to 70°C. Specifications over the –30°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls.

2

Note 3: Specification is guaranteed by design and not 100% tested in
production.

Note 4: Minimum V
battery’s ability to provide the necessary power as it enters a deeply
discharged state.

Note 5: Burst Mode operation I
by V

to get the equivalent input (battery) current.

OUT/VIN

operation after start-up is only limited by the

IN

is measured at V

Q

. Multiply this value

OUT

3400f

UW

TYPICAL PERFOR A CE CHARACTERISTICS

LTC3400/LTC3400B

Output Load Burst Mode Threshold
vs V

IN

L = 4.7µH

= 25°C

T

A

20

V

= 3.3V V

OUT

10

OUTPUT CURRENT (mA)

0

0.9

1.5 2.1 2.7 3.3

OUT

VIN (V)

= 5V

No Load Battery Current vs V

1000

V

= 3.3V

OUT

= 25°C

T

A

100

3.9 4.5

3400 G01

BATT

V

vs Temperature

OUT

3.36
FIGURE 1 CIRCUIT

I

= 10mA

O

3.34

3.32

(V)

3.30

OUT

V

3.28

3.26

3.24

–60

03060

–30

TEMPERATURE (°C)

Normalized Oscillator Frequency
vs Temperature

1.01

1.00

0.99

0.98

90 120

3400 G02

Minimum Start-Up Voltage
vs Load Current

1.4
TA = 25°C

1.3

1.2

1.1

1.0

START-UP VOLTAGE (V)

0.9

0.8

0.1

1 10 100

I

(mA) CURRENT SOURCE LOAD

OUT

SW Pin Antiringing Operation

V

SW

1V/DIV

3400 G03

BATTERY CURRENT (µA)

10

0.9

1.2

1.8

BATTERY VOLTAGE (V)

SW Pin Fixed Frequency,
Continuous Inductor Current
Operation

V

SW

1V/DIV

0V

= 1.3V 100ns/DIV 3400 G07

V

IN

V

= 3.3V

OUT

= 50mA

I

OUT

L = 6.8µH
C

= 4.7µF

OUT

2.1 2.4 2.7

3400 G04

3.01.5

0.97

NORMALIZED FREQUENCY

0.96

0.95
–50

–30 –10

Fixed Frequency and Burst Mode
Operation V

V

OUT(AC)

100mV/DIV

60mA

I

OUT

10µA

V

= 1.3V 10ms/DIV 3400 G08

IN

V

= 3.3V

OUT

= 60mA TO 10µA

I

OUT

L = 6.8µH
C

= 4.7µF

OUT

30 70 90

10 50

TEMPERATURE (°C)

3400 G05

0V

V

OUT(AC)

100mV/DIV

100mA

I

OUT

40mA

= 1.3V 100ns/DIV 3400 G06

V

IN

V

= 3.3V

OUT

I

= 10mA

OUT

L = 6.8µH

= 4.7µF

C

OUT

Transient Response

OUT

V

= 1.3V 100µs/DIV 3400 G09

IN

V

= 3.3V

OUT

= 40mA TO 100mA

I

OUT

L = 6.8µH
C

= 4.7µF

OUT

3400f

3

LTC3400/LTC3400B

U

UU

PI FU CTIO S

SW (Pin 1): Switch Pin. Connect inductor between SW
and VIN. Optional Schottky diode is connected between
SW and V
wide as possible to reduce EMI and voltage overshoot. If
the inductor current falls to zero, or SHDN is low, an
internal 100Ω antiringing switch is connected from SW to
VIN to minimize EMI.

GND (Pin 2): Signal and Power Ground. Provide a short
direct PCB path between GND and the (–) side of the output
capacitor(s).

FB (Pin 3): Feedback Input to the gm Error Amplifier.
Connect resistor divider tap to this pin. The output voltage
can be adjusted from 2.5V to 5V by:

V

OUT

SHDN (Pin 4): Logic Controlled Shutdown Input.

SHDN = High: Normal free running operation, 1.2MHz
typical operating frequency.

. Keep these PCB trace lengths as short and

OUT

= 1.23V • [1 + (R1/R2)]

SHDN = Low: Shutdown, quiescent current <1µA.
100Ω connected between SW and VIN.

Typically, SHDN should be connected to VIN through a 1M
pull-up resistor.

V

(Pin 5): Output Voltage Sense Input and Drain of the

OUT

Internal Synchronous Rectifier MOSFET. Bias is derived
from V
capacitor(s) should be as short and wide as possible. V

. PCB trace length from V

OUT

to the output filter

OUT

OUT

is held at VIN – 0.6V in shutdown due to the body diode of
the internal PMOS.

VIN (Pin 6): Battery Input Voltage. The device gets its
start-up bias from VIN. Once V
comes from V

. Thus, once started, operation is com-

OUT

exceeds VIN, bias

OUT

pletely independent from VIN. Operation is only limited by
the output power level and the battery’s internal series
resistance.

BLOCK DIAGRA

SINGLE

+

RAMP

GEN

1.2MHz

CELL
INPUT

V

6

IN

COMPARATOR

START-UP

PWM

SLEEP

OSC

W

CONTROL

SLOPE

+
–
–

Burst Mode

OPERATION

CONTROL

PWM

COMP

C
1µF

L1

4.7µH

IN

+

V

OUT

GOOD

–

A/B

A

MUX

B

SYNC

DRIVE

CONTROL

Σ

R

C

80k

C

C

150pF

C

P2

2.5pF

2.3V

SW

1

0.35Ω

CURRENT
SENSE

0.45Ω

g

m

ERROR

AMP

OPTIONAL

SCHOTTKY

–

+

FB

3

1.23V
REF

3.3V

OUTPUT

R1

1.02M
1%
(EXTERNAL)

R2
604k
1%
(EXTERNAL)

C

OUT

4.7µF

V

OUT

5

4

SHDN

4

SHUTDOWN

CONTROL

SHUTDOWN

2

GND

3400 BD

3400f

OPERATIO

LTC3400/LTC3400B

U

The LTC3400/LTC3400B are 1.2MHz, synchronous boost
converters housed in a 6-lead ThinSOT package. Able to
operate from an input voltage below 1V, the devices
feature fixed frequency, current mode PWM control for
exceptional line and load regulation. With its low R
and gate charge internal MOSFET switches, the devices
maintain high efficiency over a wide range of load current.
Detailed descriptions of the three distinct operating modes
follow. Operation can be best understood by referring to
the Block Diagram.

Low Voltage Start-Up

The LTC3400/LTC3400B will start up at a typical VIN volt­age of 0.85V or higher. The low voltage start-up circuitry
controls the internal NMOS switch up to a maximum peak
inductor current of 850mA (typ), with an approximate

1.5µs off-time during start-up, allowing the devices to
start up into an output load. Once V
start-up circuitry is disabled and normal fixed frequency
PWM operation is initiated. In this mode, the LTC3400/
LTC3400B operate independent of VIN, allowing extended
operating time as the battery can droop to several tenths
of a volt without affecting output voltage regulation. The
limiting factor for the application becomes the ability of the
battery to supply sufficient energy to the output.

Low Noise Fixed Frequency Operation

Oscillator: The frequency of operation is internally set to

1.2MHz.
Error Amp: The error amplifier is an internally compensated

transconductance type (current output) with a transconduc­tance (gm) = 33 microsiemens. The internal 1.23V reference
voltage is compared to the voltage at the FB pin to generate
an error signal at the output of the error amplifier. A volt­age divider from V
voltage via FB from 2.5V to 5V using the equation:

V

= 1.23V • [1 + (R1/R2)]

OUT

Current Sensing: A signal representing NMOS switch
current is summed with the slope compensator. The
summed signal is compared to the error amplifier output
to provide a peak current control command for the PWM.
Peak switch current is limited to approximately 850mA

to ground programs the output

OUT

exceeds 2.3V, the

OUT

DS(ON)

independent of input or output voltage. The current signal
is blanked for 40ns to enhance noise rejection.

Zero Current Comparator: The zero current comparator
monitors the inductor current to the output and shuts off
the synchronous rectifier once this current reduces to ap­proximately 20mA. This prevents the inductor current from
reversing in polarity improving efficiency at light loads.

Antiringing Control: The antiringing control circuitry pre­vents high frequency ringing of the SW pin as the inductor
current goes to zero by damping the resonant circuit
formed by L and C

Burst Mode Operation

Portable devices frequently spend extended time in low
power or standby mode, only switching to high power
drain when specific functions are enabled. In order to
improve battery life in these types of products, high power
converter efficiency needs to be maintained over a wide
output power range. In addition to its high efficiency at
moderate and heavy loads, the LTC3400 includes auto­matic Burst Mode operation that improves efficiency of
the power converter at light loads. Burst mode operation
is initiated if the output load current falls below an
internally programmed threshold (see Typical Perfor­mance graph, Output Load Burst Mode Threshold vs VIN).
Once initiated, the Burst Mode operation circuitry shuts
down most of the device, only keeping alive the circuitry
required to monitor the output voltage. This is referred to
as the sleep state. In sleep, the LTC3400 draws only 19µA
from the output capacitor, greatly en
When the output voltage has drooped approximately 1%
from nominal, the LTC3400 wakes up and commences
normal PWM operation. The output capacitor recharges
and causes the LTC3400 to reenter sleep if the output load
remains less than the sleep threshold. The frequency of
this intermittent PWM or burst operation is proportional to
load current; that is, as the load current drops further
below the burst threshold, the LTC3400 turns on less
frequently. When the load current increases above the
burst threshold, the LTC3400 will resume continuous
PWM operation seamlessly. The LTC3400B does not use
Burst Mode operation and features continous operation at
light loads, eliminating low frequency output voltage ripple
at the expense of light load efficiency.

(capacitance on SW pin).

SW

hancing efficiency.

3400f

5

LTC3400/LTC3400B

INDUCTANCE (µH)

3

60

OUTPUT CURRENT (mA)

80

110

120

160

7

11

13 21

180

140

59

15

17

19

23

3400 F03

V

IN

=1.2V

V

OUT

= 3V

V

OUT

= 3.3V

V

OUT

= 3.6V

V

OUT

= 5V

WUUU

APPLICATIO S I FOR ATIO

PCB LAYOUT GUIDELINES

The high speed operation of the LTC3400/LTC3400B
demands careful attention to board layout. You will not get
advertised performance with careless layout. Figure 2
shows the recommended component placement. A large
ground pin copper area will help to lower the chip tempera­ture. A multilayer board with a separate ground plane is
ideal, but not absolutely necessary.

(OPTIONAL)

SW

V

IN

1

GND

2

6

V

IN

V

5

OUT

Figure 3. Maximum Output Current vs
Inductance Based On 90% Efficiency

COMPONENT SELECTION

Inductor Selection

The LTC3400/LTC3400B can utilize small surface mount
and chip inductors due to their fast 1.2MHz switching
frequency. A minimum inductance value of 3.3µH is
necessary for 3.6V and lower voltage applications and

4.7µH for output voltages greater than 3.6V. Larger values
of inductance will allow greater output current capability
by reducing the inductor ripple current. Increasing the
inductance above 10µH will increase size while providing
little improvement in output current capability.

The approximate output current capability of the LTC3400/
LTC3400B versus inductance value is given in the equa­tion below and illustrated graphically in Figure 3.

SHDN

FB

3

RECOMMENDED COMPONENT PLACEMENT. TRACES
CARRYING HIGH CURRENT ARE DIRECT. TRACE AREA AT
FB PIN IS SMALL. LEAD LENGTH TO BATTERY IS SHORT

3400 F02

4

V

OUT

SHDN

Figure 2. Recommended Component Placement
for Single Layer Board

VD

II

OUT MAX P

()



•–

η





•

IN

fL

••






2

D

•–=

1

()

where:

η = estimated efficiency
IP = peak current limit value (0.6A)
VIN = input (battery) voltage
D = steady-state duty ratio = (V

– VIN)/V

OUT

OUT

f = switching frequency (1.2MHz typical)
L = inductance value

The inductor current ripple is typically set for 20% to 40%
of the maximum inductor current (IP). High frequency
ferrite core inductor materials reduce frequency depen­dent power losses compared to cheaper powdered iron
types, improving efficiency. The inductor should have low
ESR (series resistance of the windings) to reduce the I2R
power losses, and must be able to handle the peak
inductor current without saturating. Molded chokes and
some chip inductors usually do not have enough core to
support the peak inductor currents of 850mA seen on the
LTC3400/LTC3400B. To minimize radiated noise, use a
toroid, pot core or shielded bobbin inductor. See Table 1
for some suggested components and suppliers.

3400f

6

WUUU

APPLICATIO S I FOR ATIO

LTC3400/LTC3400B

Table 1. Recommended Inductors

MAX

L DCR HEIGHT

PART (µH) mΩ (mm) VENDOR

CDRH5D18-4R1 4.1 57 2.0 Sumida
CDRH5D18-100 10 124 2.0 [phone]
CDRH3D16-4R7 4.7 105 1.8 www.sumida.com
CDRH3D16-6R8 170 1.8
CR43-4R7 4.7 109 3.5
CR43-100 10 182 3.5
CMD4D06-4R7MC 4.7 216 0.8
CMD4D06-3R3MC 3.3 174 0.8

DS1608-472 4.7 60 2.9 Coilcraft
DS1608-103 10 75 2.9 [phone]
DO1608C-472 4.7 90 2.9 www.coilcraft.com

D52LC-4R7M 4.7 84 2.0 Toko
D52LC-100M 10 137 2.0 [phone]

www.tokoam.com

LQH3C4R7M24 4.7 195 2.2 Murata

www.murata.com

Output and Input Capacitor Selection

Low ESR (equivalent series resistance) capacitors should
be used to minimize the output voltage ripple. Multilayer
ceramic capacitors are an excellent choice as they have
extremely low ESR and are available in small footprints. A

2.2µF to 10µF output capacitor is sufficient for most
applications. Larger values up to 22µF may be used to
obtain extremely low output voltage ripple and improve
transient response. An additional phase lead capacitor
may be required with output capacitors larger than 10µF

to maintain acceptable phase margin. X5R and X7R
dielectric materials are preferred for their ability to main­tain capacitance over wide voltage and temperature ranges.

Low ESR input capacitors reduce input switching noise
and reduce the peak current drawn from the battery. It
follows that ceramic capacitors are also a good choice for
input decoupling and should be located as close as pos­sible to the device. A 4.7µF input capacitor is sufficient for
virtually any application. Larger values may be used with­out limitations. Table 2 shows a list of several ceramic
capacitor manufacturers. Consult the manufacturers di­rectly for detailed information on their entire selection of
ceramic parts.

Table 2. Capacitor Vendor Information

SUPPLIER PHONE WEBSITE

AVX [phone] www.avxcorp.com
Murata [phone] www.murata.com
Taiyo Yuden [phone] www.t-yuden.com

Output Diode

Use a Schottky diode such as an MBR0520L, CMDSH2-3,
1N5817 or equivalent if the converter output voltage is 4.5V
or greater. The Schottky diode carries the output current for
the time it takes for the synchronous rectifier to turn on. Do
not use ordinary rectifier diodes, since the slow recovery
times will compromise efficiency. A Schottky diode is
optional for output voltages below 4.5V, but will increase
converter efficiency by 2% to 3%.

3400f

7

LTC3400/LTC3400B

TYPICAL APPLICATIO S

U

Single Cell to 3.3V Synchronous Boost Converter

with Load Disconnect in Shutdown

+

SINGLE
AA CELL

OFF

ON

D1: CENTRAL SEMI CMDSH2-3
L1: COILCRAFT DS1608-472

C1

4.7µF

L1

4.7µH

6

4

V

IN

LTC3400

SHDN

SW

GND

1

V

2

OUT

FB

R3

510k

D1

M1

R3
510k

C2

4.7µF

Si2305DS

Q1
2N3904

3400 TA01a

5

3

R1

1.02M
1%

R2
604k
1%

V

OUT

3.3V
100mA

8

3400f

TYPICAL APPLICATIO S

LTC3400/LTC3400B

U

Single Lithium Cell to 5V, 250mA

+

LITHIUM
CELL

D1: CENTRAL SEMI CMDSH2-3
L1: SUMIDA CMD4D06-4R7

OFF

C1

4.7µF

ON

3.6V to 5V Efficiency

100

LTC3400

= 4.7µF

C

O

L = 4.7µH

90

80

70

EFFICIENCY (%)

60

L1

4.7µH

6

V

4

SHDN

SW

IN

LTC3400

GND

D1

1

5

V

OUT

3

FB

2

C2

4.7µF

R1

1.82M
1%

R2
604k
1%

3400 TA02a

50

0.1 10 100 1000

1

LOAD CURRENT (mA)

3400 TA02b

3400f

9

LTC3400/LTC3400B

TYPICAL APPLICATIO S

Single Cell AA Cell to ±3V Synchronous Boost Converter

U

L1

4.7µH

+

SINGLE
AA CELL

D1, D2: ZETEX FMND7000 DUAL DIODE
L1: COILCRAFT DS1608-472

OFF

C1

4.7µF

ON

6

4

V

IN

LTC3400

SHDN

SW

GND

C3

1µF

1

V

C2

4.7µF

3400 TA03a

OUT1

3V
90mA

V

OUT2

–3V
10mA

5

V

OUT

2

R1

1.02M
1%

3

FB

R2
750k
1%

D1 D2

C4
10µF

10

3400f

PACKAGE DESCRIPTIO

0.754

U

S6 Package

6-Lead Plastic SOT-23

(Reference LTC DWG # 05-08-1636)

0.854 ±0.127

LTC3400/LTC3400B

2.90 BSC
(NOTE 4)

3.254

0.95 BSC

1.9 BSC

RECOMMENDED SOLDER PAD LAYOUT

0.20 BSC

DATUM ‘A’

0.30 – 0.50 REF

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

0.09 – 0.20
(NOTE 3)

2.80 BSC

1.50 – 1.75
(NOTE 4)

1.00 MAX

0.95 BSC

0.80 – 0.90

PIN ONE ID

1.90 BSC

0.30 – 0.45 TYP
6 PLCS (NOTE 3)

0.01 – 0.10

S6 TSOT-23 0801

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.

3400f

11

LTC3400/LTC3400B

TYPICAL APPLICATIO

U

Single AA Cell to 2.5V Synchronous Boost Converter

+

SINGLE
AA CELL

D1: CENTRAL SEMI CMDSH2-3
L1: SUMIDA CMD4D06-3R3MC

C1

4.7µF

OFF

ON

L1

3.3µH

6

4

V

IN

LTC3400

SHDN

SW

GND

D1

1

V

C2

4.7µF

3400 TA04a

OUT

2.5V
130mA

5

V

OUT

FB

2

R1

1.02M
1%

3

R2

1.02M
1%

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OUT

to 34V

12

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

[phone] ● FAX: [phone]

●

www.linear.com

3400f

LT/TP 0302 2K • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORA TION 2001