LT3467ES6_技术文档

Final Electrical Specifications

LT3467

1.1A Step-Up DC/DC

Converter in ThinSOT^TM

with Integrated Soft-Start

June 2003

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FEATURES

DESCRIPTIO

The LT^®3467 SOT-23 switching regulator combines a

42V, 1.1Aswitchwithasoft-startfunction. Pincompatible

with the LT1930, its low V_CESATbipolar switch enables the

device to deliver high current outputs in a small footprint.

The LT3467 switches at 1.3MHz, allowing the use of tiny,

low cost and low height inductors and capacitors. High

inrushcurrentatstart-upiseliminatedusingtheprogram-

mable soft-start function. A single external capacitor sets

the current ramp rate. A constant frequency current mode

PWM architecture results in low, predictable output noise

that is easy to filter.

■

1.3MHz Switching Frequency

■

Low V_CESATSwitch: 330mV at 1.1A

■

High Output Voltage: Up to 40V

■

Wide Input Range: 2.4V to 16V

■

Dedicated Soft-Start Pin

■

5V at 540mA from 3.3V Input

■

12V at 270mA from 5V Input

■

Uses Small Surface Mount Components

■

Low Shutdown Current: <1µA

■

Pin-for-Pin Compatible with the LT1930 and LT1613

■

Low Profile (1mm) SOT-23 Package

U

The high voltage switch on the LT3467 is rated at 42V,

making the device ideal for boost converters up to 40V as

well as SEPIC and flyback designs. The LT3467 can

generate 5V at up to 540mA from a 3.3V supply or 5V at

450mA from four alkaline cells in a SEPIC design. The

LT3467 is available in a low profile (1mm) 6-lead SOT-23

package.

APPLICATIO S

■

Digital Cameras

■

White LED Power Supply

■

Cellular Phones

■

Medical Diagnostic Equipment

■

Local 5V or 12V Supply

■

TFT-LCD Bias Supply

, LTC and LT are registered trademarks of Linear Technology Corporation

ThinSOT is a trademark of Linear Technology Corporation.

■

xDSL Power Supply

U

TYPICAL APPLICATIO

Efficiency

95

90

L1

D1

2.7µH

V

IN

V

OUT

5V

2.6V TO

4.2V

V

= 4.2V

IN

= 3.3V

85

80

75

70

65

60

55

50

6

1

C1

R1

765mA if V = 4.2V,

IN

V

IN

4.7µF

402k

540mA if V = 3.3V,

IN

V

SW

IN

V

= 2.6V

IN

C4

3.3pF

360mA if V = 2.6V

IN

4

5

SHDN

OFF ON

LT3467

3

SS

FB

C2

15µF

R2

133k

C3

0.047µF

GND

2

C1, C2: X5R OR X7R, 6.3V

3467 TA05a

D1: ON SEMICONDUCTOR MBRM120

L1: SUMIDA CR43-2R7

800

900

0

100

300 400 500

700

600

200

I

(mA)

OUT

Figure 1. Single Li-Ion Cell to 5V Boost Converter

3467 TA05b

3467i

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-

tation that the interconnection ofits circuits as described herein willnotinfringe on existing patentrights.

1

LT3467

W W U W

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ABSOLUTE AXI U RATI GS

PACKAGE/ORDER I FOR ATIO

(Note 1)

ORDER PART

NUMBER

V_INVoltage .............................................................. 16V

SW Voltage ................................................–0.4V to 42V

FB Voltage .............................................................. 2.5V

Current Into FB Pin .............................................. ±1mA

SHDN Voltage ......................................................... 16V

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

TOP VIEW

SW 1

GND 2

FB 3

6 V

IN

LT3467ES6

5 SS

4 SHDN

S6 PACKAGE

6-LEAD PLASTIC TSOT-23

S6 PART MARKING

LTACH

T_JMAX= 125°C, θ_JA= 256°C/ W

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

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are T_A= 25°C.

V_IN= 3V, V_SHDN= V_INunless otherwise noted.

PARAMETER

CONDITIONS

MIN

TYP

MAX

2.4

UNITS

Minimum Operating Voltage

Maximum Operating Voltage

Feedback Voltage

2.2

V

16

1.230

1.220

1.255

1.270

1.280

V

●

FB Pin Bias Current

(Note 3)

10

1.2

50

2

nA

mA

µA

Quiescent Current

V

= 2.4V, Not Switching

SHDN

Quiescent Current in Shutdown

Reference Line Regulation

Switching Frequency

Maximum Duty Cycle

= 0.5V, V = 3V

0.01

1.3

1

IN

2.6V ≤ V ≤ 16V

0.05

1.6

%/V

MHz

%

IN

1

88

87

94

●

Minimum Duty Cycle

Switch Current Limit

10

%

A

At Minimum Duty Cycle

At Maximum Duty Cycle (Note 4)

1.4

0.8

1.8

1.2

2.5

1.9

Switch V

I

= 1.1A

= 5V

330

500

1

mV

µA

V

CESAT

SW

Switch Leakage Current

SHDN Input Voltage High

SHDN Input Voltage Low

SHDN Pin Bias Current

V

0.01

SW

2.4

0.5

V

= 3V

= 0V

16

0

32

0.1

µA

SHDN

SS Charging Current

V

= 0.5V

2

3

4.5

µA

SS

Note 1: Absolute Maximum Ratings are those values beyond which the life of

Note 3: Current flows out of the pin.

a device may be impaired.

Note 4: See Typical Performance Characteristics for guaranteed current

Note 2: The LT3467E 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.

limit vs duty cycle.

3467i

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LT3467

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TYPICAL PERFOR A CE CHARACTERISTICS

Quiescent Current vs

Temperature

FB Pin Voltage vs Temperature

SHDN Current vs SHDN Voltage

1.26

1.25

1.24

1.23

1.22

1.21

1.20

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

140

120

100

80

T

= 25°C

A

60

40

20

0

–25 –10

5

20 35 50 65 80

125

95 110

–25 –10 5 20 35 50 65 80

125

95 110

–40

0

2

4

6

12 14 16 18

8

10

TEMPERATURE (°C)

V

SHDN

(V)

3467 G03

3467 G02

3467 G01

Oscillator Frequency vs

Temperature

Switch Saturation Voltage vs

Switch Current

Current Limit vs Duty Cycle

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

1.5

1.4

1.3

1.2

1.1

1.0

0.9

T

= 25°C

A

TYPICAL

T

= 25°C

A

T

A

= 85°C

V

CESAT

GUARANTEED

100mV

/DIV

T

= –40°C

A

3467 G05

–25

0

25

50

75

125

10

50

70 80

–50

100

20 30 40

60

90

SW CURRENT 200mA/DIV

DC (%)

TEMPERATURE (°C)

3467 G04

3467 G06

Soft-Start Current vs Soft-Start

Voltage

Peak Switch Current vs Soft-Start

Voltage

Start-Up Waveform

(Figure 1 Circuit)

6

5

4

3

2

1

0

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

T

= 25°C

T = 25°C

A

V

SHDN

2V/DIV

V

OUT

1V/DIV

I

SUPPLY

0.5A/DIV

3467 G09

0

50 100 150 200 250 300 350 400 450 500

(mV)

0.5ms/DIV

0

50 100 150 200 250 300 350 400 450 500

(mV)

V

SS

3467 G07

3467 G08

3467i

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LT3467

U

PI FU CTIO S

SW (Pin 1): Switch Pin. (Collector of internal NPN power

switch) Connect inductor/diode here and minimize the

metal trace area connected to this pin to minimize EMI.

SHDN(Pin4):ShutdownPin.Tieto2.4Vormoretoenable

device. Ground to shut down.

SS(Pin5):Soft-StartPin. Placeasoft-startcapacitorhere.

Upon start-up, 4µA of current charges the capacitor to

1.255V. Use a larger capacitor for slower start-up. Leave

floating if not in use.

GND (Pin 2): Ground. Tie directly to local ground plane.

FB (Pin 3): Feedback Pin. Reference voltage is 1.255V.

Connect resistive divider tap here. Minimize trace area at

FB. Set V_OUT= 1.255V(1 + R1/R2).

V_IN(Pin 6): Input Supply Pin. Must be locally bypassed.

W

BLOCK DIAGRA

250k

SS

5

6

1

SW

1.255V

V

IN

+

–

COMPARATOR

A2

REFERENCE

–

+

A1

DRIVER

Q1

R

Q

R

C

S

V

OUT

R1 (EXTERNAL)

C

+

–

0.01Ω

Σ

FB

R2 (EXTERNAL)

RAMP

GENERATOR

SHUTDOWN

4

SHDN

3

FB

2

GND

3467 F02

1.3MHz

OSCILLATOR

Figure 2. Block Diagram

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OPERATIO

The LT3467 uses a constant frequency, current-mode

control scheme to provide excellent line and load regula-

tion. Refer to the Block Diagram above. 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 compara-

tor 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

erroramplifierA1,andissimplyanamplifiedversionofthe

difference between the feedback voltage and the reference

voltage of 1.255V. In this manner, the error amplifier sets

the correct peak current level to keep the output in regu-

lation. If the error amplifier’s output increases, more

current is delivered to the output. Similarly, if the error

decreases, less current is delivered. The soft-start feature

of the LT3467 allows for clean start-up conditions by

limiting the rate of voltage rise at the output of comparator

A1 which, in turn, limits the peak switch current. The soft-

start pin is connected to a reference voltage of 1.255V

through a 250k resistor, providing 4µA of current to

charge the soft-start capacitor. Typical values for the soft-

start capacitor range from 10nF to 200nF. The LT3467 has

a current limit circuit not shown in the Block Diagram. The

switch current is constantly monitored and not allowed to

exceedthemaximumswitchcurrent(typically1.4A). Ifthe

switch current reaches this value, the SR latch is reset

regardlessofthestateofcomparatorA2. Thiscurrentlimit

protects the power switch as well as the external compo-

nents connected to the LT3467.

3467i

4

LT3467

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APPLICATIONS INFORMATION

Duty Cycle

ofthetotalswitchcurrent.Forbetterefficiency,usesimilar

valued inductors with a larger volume. Many different

sizes and shapes are available from various manufactur-

ers. Chooseacorematerialthathaslowlossesat1.3MHz,

such as ferrite core.

The typical maximum duty cycle of the LT3467 is 94%.

The duty cycle for a given application is given by:

|V_OUT| + |V_D| – |V |

|V_OUT| + |V_D| – |V_CESAT

IN

DC =

Table 1. Inductor Manufacturers.

|

Sumida

TDK

(847) 956-0666

(847) 803-6100

(714) 852-2001

www.sumida.com

www.tdk.com

Where V_Dis the diode forward voltage drop and V_CESATis

in the worst case 330mV (at 1.1A)

Murata

www.murata.com

The LT3467 can be used at higher duty cycles, but it must

beoperatedinthediscontinuousconductionmodesothat

the actual duty cycle is reduced.

Soft-Start

The soft-start feature provides a way to limit the inrush

current drawn from the supply upon startup. An internal

250k resistor charges the external soft start capacitor to

1.255V. After the capacitor reaches 0.15V the rate of

voltage rise at the output of the comparator A1 tracks the

rate of voltage rise of the soft-start capacitor. This limits

the inrush current drawn from the supply during startup.

Once the part is shut down, the soft start capacitor is

quicklydischargedto0.4V,thenslowlydischargedthrough

the 250k resistor to ground. If the part is to be shut down

and re-enabled in a short period of time while soft-start is

used, you must ensure that the soft-start capacitor has

enough time to discharge before re-enabling the part.

Typical values of the soft-start capacitor range from 10nF

to 200nF.

Setting Output Voltage

R1 and R2 determine the output voltage.

Vout = 1.255V (1+ R1/R2)

Switching Frequency and Inductor Selection

TheLT3467switchesat1.3MHz,allowingforsmallvalued

inductors to be used. 4.7µH or 10µH will usually suffice.

Choose an inductor that can handle at least 1.2A without

saturating, and ensure that the inductor has a low DCR

(copper-wire resistance) to minimize I²R power losses.

Note that in some applications, the current handling

requirements of the inductor can be lower, such as in the

SEPIC topology where each inductor only carries one half

Supply Current of Figure 1 During

Startup without Soft-Start Capacitor

Supply Current of Figure 1 During

Startup with 47nF Soft-Start Capacitor

V_OUT

1V/DIV

V_OUT

1V/DIV

I_SUPPLY

0.5A/DIV

I_SUPPLY

0.5A/DIV

0.1ms/DIV

0.5ms/DIV

3467i

5

LT3467

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APPLICATIONS INFORMATION

CAPACITOR SELECTION

By choosing the appropriate values for the resistor and

capacitor, the zero frequency can be designed to improve

the phase margin of the overall converter. The typical

target value for the zero frequency is between 35kHz to

55kHz. Figure 3 shows the transient response of the step-

up converter from Figure 8 without the phase lead capaci-

tor C4. Although adequate for many applications, phase

margin is not ideal as evidenced by 2-3 “bumps” in both

the output voltage and inductor current. A 22pF capacitor

for C4 results in ideal phase margin, which is revealed in

Figure 4 as a more damped response and less overshoot.

Low ESR (equivalent series resistance) capacitors should

beusedattheoutputtominimizetheoutputripplevoltage.

Multi-layer ceramic capacitors are an excellent choice, as

they have extremely low ESR and are available in very

small packages. X5R dielectrics are preferred, followed by

X7R, as these materials retain the capacitance over wide

voltage and temperature ranges. A 4.7µF to 15µF output

capacitor is sufficient for most applications, but systems

withverylowoutputcurrentsmayneedonlya1µFor2.2µF

outputcapacitor. SolidtantalumorOSCONcapacitorscan

be used, but they will occupy more board area than a

ceramicandwillhaveahigherESR.Alwaysuseacapacitor

with a sufficient voltage rating.

LOAD CURRENT

100mA/DIV

AC COUPLED

Ceramic capacitors also make a good choice for the input

decoupling capacitor, which should be placed as close as

possible to the LT3467. A 1µF to 4.7µF input capacitor is

sufficient for most applications. Table 2 shows a list of

several ceramic capacitor manufacturers. Consult the

manufacturers for detailed information on their entire

selection of ceramic parts.

V_OUT

200mV/DIV

AC COUPLED

I_L2

5A/DIV

AC COUPLED

20µs/DIV

3467 F03

Table 2. Ceramic Capacitor Manufacturers

Figure 3. Transient Response of Figure 8's Step-Up

Converter without Phase Lead Capacitor

Taiyo Yuden

AVX

(408) 573-4150

(803) 448-9411

(714) 852-2001

www.t-yuden.com

www.avxcorp.com

www.murata.com

Murata

LOAD CURRENT

100mA/DIV

ThedecisiontouseeitherlowESR(ceramic)capacitorsor

the higher ESR (tantalum or OSCON) capacitors can affect

the stability of the overall system. The ESR of any capaci-

tor, along with the capacitance itself, contributes a zero to

the system. For the tantalum and OSCON capacitors, this

zero is located at a lower frequency due to the higher value

of the ESR, while the zero of a ceramic capacitor is at a

much higher frequency and can generally be ignored.

AC COUPLED

V_OUT

200mV/DIV

AC COUPLED

I_L2

5A/DIV

AC COUPLED

20µs/DIV

3467 F04

A phase lead zero can be intentionally introduced by

placing a capacitor (C4) in parallel with the resistor (R1)

betweenV_OUTandV_FBasshowninFigure1.Thefrequency

of the zero is determined by the following equation.

Figure 4. Transient Response of Figure 8's Step-Up

Converter with 22pF Phase Lead Capacitor

1

ƒ_Z=

2π •R1•C4

3467i

6

LT3467

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APPLICATIONS INFORMATION

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Compensation—Theory

DIODE SELECTION

Like all other current mode switching regulators, the

LT3467 needs to be compensated for stable and efficient

operation. Two feedback loops are used in the LT3467: a

fast current loop which does not require compensation,

and a slower voltage loop which does. Standard Bode plot

analysis can be used to understand and adjust the voltage

feedback loop.

ASchottkydiodeisrecommendedforusewiththeLT3467.

The Philips PMEG 2005 is a very good choice. Where the

switch voltage exceeds 20V, use the PMEG 3005 (a 30V

diode). Where the switch voltage exceeds 30V, use the

PMEG 4005 (a 40V diode). These diodes are rated to

handle an average forward current of 0.5A. In applications

where the average forward current of the diode exceeds

0.5A, a Philips PMEG 2010 rated at 1A is recommended.

For higher efficiency, use a diode with better thermal

characteristics such as the On Semiconductor MBRM120

(a 20V diode) or the MBRM140 (a 40V diode).

As with any feedback loop, identifying the gain and phase

contribution of the various elements in the loop is critical.

Figure 6 shows the key equivalent elements of a boost

converter. Because of the fast current control loop, the

power stage of the IC, inductor and diode have been

replaced by the equivalent transconductance amplifier

SETTING OUTPUT VOLTAGE

g

_mp. g_mpactsasacurrentsourcewheretheoutputcurrent

To set the output voltage, select the values of R1 and R2

(see Figure 1) according to the following equation.

is proportional to the V_Cvoltage. Note that the maximum

output current of g_mpis finite due to the current limit in the

IC.

V_OUT

1.255V

R1= R2

– 1

From Figure 6, the DC gain, poles and zeroes can be

calculated as follows:

2

A good value for R2 is 13.3k which sets the current in the

resistor divider chain to 1.255V/13.3k = 94µA.

Output Pole: P1=

2• π •R_L•C_OUT

1

Error Amp Pole: P2 =

LAYOUT HINTS

2• π •R_O•C_C

The high speed operation of the LT3467 demands careful

attention to board layout. You will not get advertised

performance with careless layout. Figure 5 shows the

recommended component placement.

1

Error Amp Zero: Z1=

2• π •R_C•C_C

1.255

V_OUT

1

2

DC GAIN: A =

•g_ma•R_O•g_mp•R_L•

1

ESR Zero: Z2 =

2• π •R_ESR•C_OUT

L1

D1

C1

V

²•R_L

IN

V

IN

V

RHP Zero: Z3 =

OUT

2• π •V_OUT²•L

C2

1

2

3

6

5

4

C

SS

f_S

3

GND

High Frequency Pole: P3 >

SHDN

FB

R2

R1

1

Phase Lead Zero: Z4 =

2• π •R1•C_PL

1

3467 F05

C3

Phase Lead Pole:P4 =

V

OUT

R1•R2

R1+ R2

2• π •C_PL

•

Figure 5. Suggested Layout

3467i

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LT3467

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APPLICATIONS INFORMATION

Table 3. Bode Plot Parameters

–

Parameter

Value

10.4

15

Units

Ω

Comment

g

mp

V

OUT

R

Application Specific

Not Adjustable

Adjustable

L

+

C

R

L

PL

ESR

C

OUT

µF

C

OUT

1.255V

REFERENCE

+

–

R

ESR

10

mΩ

MΩ

pF

V

C

g

ma

R1

R2

R

0.4

60

O

C

R

O

C

3.3

100

402

133

5

pF

PL

3467 F06

R

kΩ

V

Not Adjustable

Adjustable

C : COMPENSATION CAPACITOR

C

OUT

PL

ma

mp

C

g

: OUTPUT CAPACITOR

R1

R2

: PHASE LEAD CAPACITOR

: TRANSCONDUCTANCE AMPLIFIER INSIDE IC

: POWER STAGE TRANSCONDUCTANCE AMPLIFIER

Adjustable

R : COMPENSATION RESISTOR

C

V

OUT

Application Specific

Not Adjustable

Application Specific

Not Adjustable

R : OUTPUT RESISTANCE DEFINED AS V

DIVIDED BY I

LOAD(MAX)

L

OUT

R : OUTPUT RESISTANCE OF g

O

ma

V

IN

3.3

35

V

R1, R2: FEEDBACK RESISTOR DIVIDER NETWORK

: OUTPUT CAPACITOR ESR

R

ESR

g

µmho

mho

µH

ma

7.5

2.7

1.3

Figure 6. Boost Converter Equivalent Model

mp

L

The Current Mode zero is a right half plane zero which can

be an issue in feedback control design, but is manageable

with proper external component selection.

f

MHz

S

From Figure 7, the phase is –138° when the gain reaches

0dB giving a phase margin of 42°. This is more than

adequate. The crossover frequency is 37kHz.

Using the circuit of Figure 1 as an example, the following

tableshowstheparametersusedtogeneratetheBodeplot

shown in Figure 7.

50

40

0

–45

30

–90

20

–135

–180

–225

–270

–315

–360

–405

–450

10

0

–10

–20

–30

GAIN

–40

–50

PHASE

100

1k

10k

100k

1M

FREQUENCY (Hz)

3467 F07

Figure 7.Bode Plot of 3.3V to 5V Application

3467i

8

LT3467

U

TYPICAL APPLICATIO S

Lithium-Ion to 6V Step-Up DC/DC Converter

Li-Ion to 6V

L1

95

90

85

80

75

70

65

60

55

50

D1

2.2µH

V

IN

V

OUT

6V

V

= 4.2V

IN

2.7V

TO 4.2V

6

1

R1

275mA AT V = 2.7V

V

= 3.8V

IN

501k

V

SW

490mA AT V = 3.8V

IN

C1

2.2µF

IN

V

= 2.7V

IN

C3

1.8pF

4

5

590mA AT V = 4.2V

IN

SHDN

C4

SHDN

LT3467

3

SS

FB

C2

15µF

R2

133k

GND

2

0.047µF

C1, C2: X5R OR X7R, 6.3V

3467 TA01

D1: ON SEMICONDUCTOR MBRM120

L1: SUMIDA CR43-2R2

0

100

300 400 500 600 700

(mA)

200

I

OUT

3467 TA01b

4-Cell to 5V SEPIC Converter

C3

1µF

L1

10µH

D1

V

OUT

5V

4V TO 6.5V

325mA AT V = 4V

6

1

C1

IN

400mA AT V = 5V

IN

2.2µF

V

SW

IN

SHDN

LT3467

450mA AT V = 6.5V

4

IN

255k

SHDN

C5

4.7pF

4-CELL

BATTERY

3

5

L2

10µH

C2

10µF

SS

FB

C4

0.047µF

GND

2

84.5k

C1, C3: X5R or X7R, 10V

C2: X5R or X7R, 6.3V

3467 TA02

D1: PHILIPS PMEG 2010

L1, L2: MURATA LQH32CN100K33L

5V to 40V Boost Converter

±15V Dual Output Converter with Output Disconnect

C4

1µF

L1

10µH

L1

D1

2.7µH

V

OUT

V

15V

IN

40V

5V

100mA

20mA

C1

6

1

6

1

C1

R3

R1

147k

2.2µF

4.7µF

C5

V

SW

V

SW

1Ω

IN

R1

412k

4

5

4

5

1µF

OFF ON

SHDN

D2

C2

2.2µF

C2

1µF

LT3467

3

SS

FB

SS

C6

0.047µF

R2

13.3k

C3

0.1µF

R2

13.3k

GND

2

GND

2

D3

C1: X5R or X7R, 6.3V

C2: X5R or X7R, 50V

D1: ON SEMICONDUCTOR, MBRM140

L1: SUMIDA CD43-2R7

C3

2.2µF

C1: X5R or X7R, 6.3V

C2 TO C5: X5R or X7R, 16V

D1 TO D4: PHILIPS PMEG 2005

L1: SUMIDA CR43-100

3467 TA03

R4

D4

1Ω

–15V

100mA

3467 TA04

3467i

9

LT3467

TYPICAL APPLICATIO S

U

9V, 18V, –9V Triple Output TFT-LCD Bias Supply with Soft-Start

D1

D2

18V

10mA

C4

C3

0.1µF

1µF

L1

4.7µH

Start-Up Waveforms

D5

V

9V

220mA

IN

9V OUTPUT

5V/DIV

3.3V

6

1

C1

2.2µF

R1

124k

V

SW

IN

4

5

V

SHDN

–9V OUTPUT

5V/DIV

LT3467

C5

10µF

3

SS

FB

3.3V

GND

2

C7

0.1µF

R2

20k

18V OUTPUT

10V/DIV

0V

C2

0.1µF

C1: X5R OR X7R, 6.3V

C2,C3, C5, C6: X5R OR X7R, 10V

C4: X5R OR X7R, 25V

D1 TO D4: PHILIPS BAT54S OR EQUIVALENT

D5: PHILIPS PMEG 2005

L1: PANASONIC ELT5KT4R7M

I_L10.5A/DIV

D4

D3

C6

1µF

2ms/DIV

–9V

10mA

3467 TA07a

8V, 23V, –8V Triple Output TFT-LCD Bias Supply with Soft-Start

D1

D2

D3

D4

23V

10mA

C3

0.1µF

C4

0.1µF

C5

0.1µF

C6

1µF

Start-Up Waveforms

L1

4.7µH

D7

8V OUTPUT

5V/DIV

V

8V

270mA

IN

3.3V

SHDN

3.3V

6

1

C1

–8V OUTPUT

5V/DIV

R1

113k

V

SW

2.2µF

IN

4

5

V

SHDN

C7

10µF

LT3467

3

SS

FB

23V OUTPUT

10V/DIV

GND

2

R2

21k

0V

C9

C2

0.1µF

I_L10.5A/DIV

C1: X5R OR X7R, 6.3V

D5

D6

C2 TO C4, C7, C8: X5R OR X7R, 10V

C5: X5R OR X7R, 16V

2ms/DIV

C8

C6: X5R OR X7R, 25V

1µF

D1 TO D6: PHILIPS BAT54S OR EQUIVALENT

D7: PHILIPS PMEG 2005

–8V

10mA

3467 TA08a

L1: PANASONIC ELT5KT4R7M

3467i

10

LT3467

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

3467i

11

LT3467

U

TYPICAL APPLICATIO S

5V to 12V Efficiency

L1

D1

4.7µH

V

OUT

V

IN

5V

90

85

80

75

70

65

60

55

50

12V

C1

270mA

6

1

R1

2.2µF

115k

V

SW

IN

C4*

22pF

4

5

SHDN

C2

10µF

LT3467

3

SS

FB

C3

0.047µF

R2

13.3k

GND

2

C1: X5R OR X7R, 6.3V

C2: X5R OR X7R, 16V

D1: PHILIPS PMEG 2010

L1: SUMIDA CR43-4R7

*OPTIONAL

3467 TA06a

300

0

50

100 150 200 250

350

I

(mA)

OUT

3467 TA06b

Figure 8. 5V to 12V, 270mA Step-Up Converter

RELATED PARTS

PART NUMBER

DESCRIPTION

COMMENTS

V : 2.7V to 30V, V

LT1371/LT1371HV

3A (I ), 500kHz, High Efficiency

: 35V/42V,

OUT(MAX)

SW

IN

Step-Up DC/DC Converter

I : 4mA, I : <12µA, DD,TO220-7, S20 Package

Q SD

LT1613

550mA (I ), 1.4MHz, High Efficiency Step-Up

90% Efficiency, V : 0.9V to 10V, V

: 34V, I : 3mA,

SW

IN

OUT(MAX)

Q

DC/DC Converter

I : <1µA, ThinSOT Package

SD

LT1615/LT1615-1

LT1618

300mA/80mA (I ), High Efficiency Step-Up DC/DC Converter

V

SD

= 1V to 15V, V

: 34V, I : 20µA,

SW

IN

OUT(MAX) Q

I

: <1µA, ThinSOT Package

1.5A (I ), 1.25MHz, High Efficiency

90% Efficiency, V : 1.6V to 18V, V : 35V,

OUT(MAX)

I : 1.8mA, I : <1µA, MS Package

Q SD

SW

IN

Step-Up DC/DC Converter

LTC1700

No R

^TM, 530kHz, Synchronous Step-Up DC/DC Controller 95% Efficiency, V : 0.9V to 5V, I : 200µA, I : <10µA,

SENSE IN Q SD

MS Package

LTC1871

Wide Input Range, 1MHz, No R

Flyback and SEPIC Controller

Current Mode Boost,

92% Efficiency, V : 2.5V to 36V, I : 250µA, I : <10µA,

SENSE

IN

Q

SD

MS Package

LT1930/LT1930A

LT1946/LT1946A

LT1961

1A (I ), 1.2MHz/2.2MHz, High Efficiency

High Efficiency, V : 2.6V to 16V, V

Q SD

: 34V,

SW

IN

OUT(MAX

Step-Up DC/DC Converter

I : 4.2mA/5.5mA, I : <1µA, ThinSOT Package

1.5A (I ), 1.2MHz/2.7MHz, High Efficiency

High Efficiency, V : 2.45V to 16V, V

: 34V,

OUT(MAX)

SW

IN

Step-Up DC/DC Converter with Soft-Start

I : 3.2mA, I : <1µA, MS8 Package

Q SD

1.5A (I ), 1.25MHz, High Efficiency

90% Efficiency, V : 3V to 25V, V

: 35V,

SW

IN

OUT(MAX)

Step-Up DC/DC Converter

I : 0.9mA, I : 6µA, MS8E Package

Q SD

LTC3400/LTC3400B

LTC3401

600mA (I ), 1.2MHz, Synchronous Step-Up DC/DC Converter 92% Efficiency, V : 0.85V to 5V, V

: 5V,

SW

IN

OUT(MAX)

I : 19µA/300µA, I : <1µA, ThinSOT Package

Q

SD

1A (I ), 3MHz, Synchronous Step-Up DC/DC Converter

97% Efficiency, V : 0.5V to 5V, V

: 5.5V,

SW

IN

OUT(MAX)

I : 38µA, I : <1µA, MS Package

Q

SD

LTC3402

2A (I ), 3MHz, Synchronous Step-Up DC/DC Converter

97% Efficiency, V : 0.5V to 5V, V

IN

: 5.5V,

SW

I : 38µA, I : <1µA, MS Package

Q

SD

LTC3464

85mA (I ), High Efficiency Step-Up DC/DC Converter

V : 2.3V to 10V, V

: 34V,

SW

IN

OUT(MAX)

with Integrated Schottky and PNP Disconnect

I : 25µA, I : <1µA, ThinSOT Package

Q SD

No R

is a trademark of Linear Technology Corporation.

SENSE

3467i

LT/TP 0603 1K • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

12

●

(408) 432-1900 FAX: (408) 434-0507 www.linear.com

LINEAR TECHNOLOGY CORPORATION 2003


型号：	LT3467ES6
厂家：	Linear
描述：	LT3467 - 1.1A Step-Up DC/DC Converter with Integrated Soft-Start; Package: SOT; Pins: 6; Temperature Range: -40°C to 85°C 开关光电二极管输出元件
文件：	总12页 (文件大小：351K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LT3467ES6 [Linear]

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