LT3468ES5-1_技术文档

Final Electrical Specifications

LT3468/LT3468-1

Photoflash Capacitor

Charger in ThinSOT^TM

October 2003

U

DESCRIPTIO

FEATURES

TheLT^®3468/LT3468-1arehighlyintegratedICsdesigned

to charge photoflash capacitors in digital and film cam-

eras. A new control technique* allows for the use of

extremely small transformers. Each device contains an

on-chip high voltage NPN power switch. Output voltage

detection* is completely contained within the device,

eliminating the need for any discrete zener diodes or

resistors. The output voltage can be adjusted by simply

changing the turns ratio of the transformer. The LT3468

has a primary current limit of 1.4A while the LT3468-1 has

a 0.7A limit. These different current limit levels result in

well controlled input currents of 500mA for the LT3468

and 225mA for the LT3468-1. Aside from the differing

current limit, the two devices are otherwise equivalent.

■

Highly Integrated IC Reduces Solution Size

■

Uses Small Transformers:

5.8mm × 5.8mm × 3mm

Fast Photoflash Charge Times:

■

4.6s for LT3468 (0V to 320V, 100µF, V_IN= 3.6V)

5.5s for LT3468-1 (0V to 320V, 50µF, V_IN= 3.6V)

■

Controlled Input Current:

500mA (LT3468)

225mA (LT3468-1)

Supports Operation from Single Li-Ion Cell, or Any

Supply from 2.5V up to 16V

Adjustable Output Voltage

No Output Voltage Divider Needed

■

Charges Any Size Photoflash Capacitor

Low Profile (1mm) SOT-23 Package

■

The CHARGE pin gives full control of the part to the user.

DrivingCHARGElowputsthepartinshutdown. TheDONE

pin indicates when the part has completed charging. The

LT3468 series of parts are housed in tiny low profile

(1mm) SOT-23 packages.

U

APPLICATIO S

■

Digital / Film Camera Flash

■

PDA / Cell Phone Flash

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

ThinSOT is a trademark of Linear Technology Corporation. *U.S. Patent # 6, 518, 733

■

Emergency Strobe

U

TYPICAL APPLICATIO S

DANGER HIGH VOLTAGE – OPERATION BY HIGH VOLTAGE TRAINED PERSONNEL ONLY

T1

1:10.2

T1

D1

1:10.2

V

IN

320V

2.5V TO 8V

1

2

4

5

2.5V TO 8V

4

3

5

6

C1

4.7µF

C1

4.7µF

+

C

+

OUT

C

OUT

PHOTOFLASH

CAPACITOR

PHOTOFLASH

CAPACITOR

V

IN

SW

V

IN

SW

LT3468-1

R1

100k

D2

R1

100k

D2

LT3468

DONE

GND

DONE

GND

CHARGE

C1: 4.7µF, X5R OR X7R, 10V

T1: KIJIMA MUSEN PART# SBL-5.6-1, L = 10µH, N = 10.2

PRI

T1: KIJIMA MUSEN PART# SBL-5.6S-1, L = 24µH, N = 10.2

PRI

D1: VISHAY GSD2004S DUAL DIODE CONNECTED IN SERIES

D2: ZETEX ZHCS400 OR EQUIVALENT

R1: PULL UP RESISTOR NEEDED IF DONE PIN USED

D1: VISHAY GSD2004S DUAL DIODE CONNECTED IN SERIES

D2: ZETEX ZHCS400 OR EQUIVALENT

R1: PULL UP RESISTOR NEEDED IF DONE PIN USED

3468 TA01

3468 TA02

Figure 1. LT3468 Photoflash Charger Uses

High Efficiency 4mm Tall Transformer

Figure 2. LT3468-1 Photoflash Charger Uses

High Efficiency 3mm Tall Transformer

34681i

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.

1

LT3468/LT3468-1

W W

U W

U

W

U

ABSOLUTE AXI U RATI GS

PACKAGE/ORDER I FOR ATIO

(Note 1)

ORDER PART

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

SW Voltage ................................................–0.4V to 50V

CHARGE Voltage...................................................... 10V

DONE Voltage .......................................................... 10V

Current into DONE Pin .......................................... ±1mA

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

NUMBER

TOP VIEW

LT3468ES5

LT3468ES5-1

SW 1

GND 2

5 VIN

DONE 3

4 CHARGE

S5 PART

MARKING

S5 PACKAGE

5-LEAD PLASTIC SOT-23

T_JMAX= 125°C, θ_JA= 256°C/W

LTAEC

LTAGQ

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 T_A= 25°C. V_IN= 3V, V_CHARGE= V_INunless otherwise noted. (Note 2) Specifications

are for both the LT3468 and LT3468-1 unless otherwise noted.

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Quiescent Current

Not Switching

5

0

8

1

mA

µA

V

= 0V

CHARGE

Input Voltage Range

Switch Current Limit

●

2.5

16

V

LT3468 (Note 3)

LT3468-1

1.1

0.45

1.2

0.55

1.3

0.65

A

Switch V

LT3468, I = 1A

330

150

430

200

mV

CESAT

SW

LT3468-1, I = 400mA

SW

V

Comparator Trip Voltage

Comparator Overdrive

Measured as V – V

●

31

10

31.5

200

36

32

400

80

V

mV

OUT

SW

IN

300ns Pulse Width

DCM Comparator Trip Voltage

CHARGE Pin Current

Measured as V – V

SW

IN

V

= 3V

= 0V

15

0

40

0.1

µA

CHARGE

Switch Leakage Current

CHARGE Input Voltage High

CHARGE Input Voltage Low

DONE Output Signal High

DONE Output Signal Low

DONE Leakage Current

V

= V = 5V, in Shutdown

●

0.01

1

µA

V

IN

SW

1

0.3

V

100kΩ from V to DONE

3

V

IN

33µA into DONE Pin

100

20

200

100

mV

nA

V

= 3V, DONE NPN Off

DONE

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

of a device may be impaired.

operating temperature range are assured by design, characterization and

correlation with statistical process.

Note 2: The LT3468E/LT3468E-1 are guaranteed to meet performance

specifications from 0°C to 70°C. Specifications over the –40°C to 85°C

Note 3: Specifications are for static test. Current limit in actual application

will be slightly higher.

34681i

2

LT3468/LT3468-1

U W

TYPICAL PERFOR A CE CHARACTERISTICS ^{LT3468 curves use the circuit of Figure 1 and}

LT3468-1 curves use the circuit of Figure 2 unless otherwise noted.

LT3468 Charging Waveform

LT3468-1 Charging Waveform

LT3468 Charge Time

10

9

8

7

6

5

4

3

2

1

0

V_IN= 3.6V

C_OUT= 100µF

V_IN= 3.6V

C_OUT= 50µF

T

= 25°C

A

V_OUT

50V/DIV

C

= 100µF

OUT

AVERAGE

INPUT

CURRENT

1A/DIV

AVERAGE

INPUT

CURRENT

0.5A/DIV

C

= 50µF

OUT

3

1s/DIV

3468 G01

3468 G02

2

4

5

6

7

8

9

V

(V)

IN

3468 G03

LT3468-1 Charge Time

LT3468 Input Current

LT3468-1 Input Current

10

9

8

7

6

5

4

3

2

1

0

800

600

400

200

0

400

300

200

100

0

T

= 25°C

T

= 25°C

T = 25°C

A

V

IN

= 2.8V

V

IN

= 2.8V

V

IN

= 4.2V

V

IN

= 4.2V

C

5

= 50µF

OUT

V

IN

= 3.6V

V

IN

= 3.6V

C

= 20µF

OUT

3

2

4

6

(V)

7

8

9

0

50

100 150 200 250 300

(V)

0

50

100 150 200 250 300

(V)

V

OUT

IN

OUT

3468 G04

3468 G05

3468 G06

LT3468 Efficiency

LT3468-1 Efficiency

90

80

70

60

50

40

90

80

70

60

50

40

T

= 25°C

T

= 25°C

A

V

= 4.2V

V

= 4.2V

IN

V

IN

= 2.8V

V

= 2.8V

IN

V

= 3.6V

V

IN

= 3.6V

IN

50

100

150

V

200

(V)

250

300

50

100

150

200

(V)

250

300

V

OUT

3468 G07

3468 G08

34681i

3

LT3468/LT3468-1

U W

TYPICAL PERFOR A CE CHARACTERISTICS ^{LT3468 curves use the circuit of Figure 1 and}

LT3468-1 curves use the circuit of Figure 2 unless otherwise noted.

LT3468 Output Voltage

LT3468-1 Output Voltage

LT3468 Switch Current Limit

324

323

322

321

320

319

318

324

323

322

321

320

319

318

1.5

1.4

1.3

1.2

1.1

V

= 3V

IN

OUT

= 0V

T

= –40°C

A

T

A

= –40°C

A

T

= 25°C

T

= 25°C

A

T

= 85°C

T

= 85°C

A

2

3

4

5

6

7

8

2

3

4

5

6

7

8

–40 –20

0

20

40

60

80 100

V

IN

(V)

V

IN

(V)

TEMPERATURE (°C)

3468 G09

3468 G10

3468 G11

LT3468-1 Switch Current Limit

LT3468 Switching Waveform

0.700

0.660

0.620

0.580

0.540

0.500

V_IN= 3.6V

V_OUT= 100V

V_IN= 3.6V

V

= 3V

IN

OUT

V_OUT= 300V

= 0V

V_SW

10V/DIV

I_PRI

1A/DIV

I_PRI

1A/DIV

1µs/DIV

3468 G13

3468 G14

–40 –20

0

20

40

60

80 100

TEMPERATURE (°C)

3468 G12

LT3468/LT3468-1 Switch

Breakdown Voltage

LT3468-1 Switching Waveform

50

45

40

35

30

25

20

15

10

5

V_IN= 3.6V

V_OUT= 100V

SW PIN IS RESISTIVE UNTIL BREAKDOWN

VOLTAGE DUE TO INTEGRATED

RESISTORS. THIS DOES NOT INCREASE

QUIESCENT CURRENT OF PART

V_OUT= 300V

V_SW

T = 25°C

10V/DIV

T = –40°C

T = 85°C

I_PRI

1A/DIV

I_PRI

1A/DIV

1µs/DIV

3468 G15

3468 G16

V

IN

= V

CHARGE

= 5V

0

10 20 30 40 50 60 70 80 90 100

SWITCH VOLTAGE (V)

3468 G17

34681i

4

LT3468/LT3468-1

U

PI FU CTIO S

SW (Pin 1): Switch Pin. This is the collector of the internal

NPN Power switch. Minimize the metal trace area con-

nected to this pin to minimize EMI. Tie one side of the

primary of the transformer to this pin. The target output

voltage is set by the turns ratio of the transformer.

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

DONE (Pin 3): Open NPN Collector Indication Pin. When

target output voltage is reached, NPN turns on. This pin

needs a pull-up resistor or current source.

CHARGE (Pin 4): Charge Pin. A low (<0.3V) to high (>1V)

transition on this pin puts the part into power delivery

mode. Once the target output voltage is reached, the part

will stop charging the output. Toggle this pin to start

charging again. Ground to shut down.

Choose Turns Ratio N by the following equation:

V

_OUT+ 2

31. 5

N =

Where: V_OUTis the desired output voltage.

V_IN(Pin 5): Input Supply Pin. Must be locally bypassed

with a good quality ceramic capacitor. Input supply must

be 2.5V or higher.

You must tie a Schottky diode from GND to SW, with the

anode at GND for proper operation of the circuit. Please

refer to the applications section for further information.

34681i

5

LT3468/LT3468-1

W

BLOCK DIAGRA

D1

T1

V

TO BATTERY

OUT

PRIMARY

SECONDARY

C1

D2

DONE

3

V

SW

1

IN

+

C

OUT

5

PHOTOFLASH

CAPACITOR

R2

60k

Q3

DCM COMPARATOR

+

ONE-

SHOT

A3

–

+

36mV

–

Q2

Q1

ENABLE

MASTER

LATCH

R1

2.5k

DRIVER

S

Q

S

Q

R

Q1

R

Q

+

–

A2

1.25V

REFERENCE

+

–

R

SENSE

A1

20mV

V

COMPARATOR

OUT

+–

CHARGE

GND

ONE-

SHOT

4

2

3486 BD

LT3468: R

= 0.015Ω

SENSE

LT3468-1: R

= 0.03Ω

Figure 3

U

OPERATIO

The LT3468/LT3468-1 are designed to charge photoflash

capacitorsquicklyandefficiently.Theoperationofthepart

can be best understood by referring to Figure 3. When the

CHARGE pin is first driven high, a one shot sets both SR

latches in the correct state. The power NPN device, Q1,

turns on and current begins ramping up in the primary of

transformer T1. Comparator A1 monitors the switch cur-

rent and when the peak current reaches 1.4A (LT3468) or

0.7A (LT3468-1), Q1 is turned off. Since T1 is utilized as

a flyback transformer, the flyback pulse on the SW pin will

cause the output of A3 to be high. The voltage on the SW

pin needs to be at least 36mV higher than V_INfor this to

happen.

During this phase, current is delivered to the photoflash

capacitor via the secondary and diode D1. As the second-

arycurrentdecreasestozero,theSWpinvoltagewillbegin

to collapse. When the SW pin voltage drops to 36mV

above V_INor lower, the output of A3 (DCM Comparator)

will go low. This fires a one shot which turns Q1 back on.

This cycle will continue to deliver power to the output.

Output voltage detection is accomplished via R2, R1, Q2,

and comparator A2 (V_OUTComparator). Resistors R1 and

R2 are sized so that when the SW voltage is 31.5V above

V_IN, the output of A2 goes high which resets the master

latch. This disables Q1 and halts power delivery. Power

deliverycanonlyberestartedbytogglingtheCHARGEPin.

34681i

6

LT3468/LT3468-1

U

W

U U

APPLICATIO S I FOR ATIO

Choosing The Right Device (LT3468/LT3468-1)

the amplitude of the reflected voltage from the output to

theSWpin. ChooseNaccordingtothefollowingequation:

The only difference between the two versions of the

LT3468 is the peak current level. For the fastest possible

charge time, use the LT3468. The LT3468-1 has a lower

peak current capability, and is designed for applications

that need a more limited drain on the batteries. Due to the

lower peak current, the LT3468-1 can use a physically

smaller transformer.

V

_OUT+ 2

31. 5

N =

Where: V_OUTis the desired output voltage. The number

2 in the numerator is used to include the effect of the

voltage drop across the output diode(s).

Thus for a 320V output, N should be 322/31.5 or 10.2.

For a 300V output, choose N equal to 302/31.5 or 9.6.

Transformer Design

The flyback transformer is a key element for any LT3468/

LT3468-1design.Itmustbedesignedcarefullyandchecked

that it does not cause excessive current or voltage on any

pin of the part. The main parameters that need to be

designed are shown in Table 1.

The next parameter that needs to be set is the primary

inductance, L_PRI. Choose L_PRIaccording to the following

formula:

V

_OUT• 200 •10⁻⁹

L_PRI

≥

The first transformer parameter that needs to be set is the

turns ratio N. The LT3468/LT3468-1 accomplish output

voltage detection by monitoring the flyback waveform on

the SW pin. When the SW voltage reaches 31.5V higher

thantheV_INvoltage,thepartwillhaltpowerdelivery.Thus,

the choice of N sets the target output voltage as it changes

N •I_PK

Where: V_OUTis the desired output voltage. N is

the transformer turns ratio. I_PKis 1.4 (LT3468), 0.7

(LT3468-1)

L_PRIneeds to be equal or larger than this value to ensure

that the LT3468/LT3468-1 has adequate time to respond

to the flyback waveform.

Table 1. Recommended Transformer Parameters

TYPICAL RANGE

LT3468

TYPICAL RANGE

LT3468-1

PARAMETER

NAME

UNITS

µH

L

Primary Inductance

>5

100 to 300

8 to 12

>500

>10

200 to 500

8 to 12

>500

PRI

Primary Leakage Inductance

Secondary: Primary Turns Ratio

Secondary to Primary Isolation Voltage

Primary Saturation Current

Primary Winding Resistance

Secondary Winding Resistance

nH

LEAK

N

V

A

ISO

I

>1.6

>0.8

SAT

R

<300

<500

mΩ

Ω

PRI

<40

<80

SEC

34681i

7

LT3468/LT3468-1

U

W

U U

APPLICATIO S I FOR ATIO

V_IN= 5V

_OUT= 320V

All other parameters need to meet or exceed the recom-

mended limits as shown in Table 1. A particularly impor-

tant parameter is the leakage inductance, L_LEAK. When the

power switch of the LT3468/LT3468-1 turns off, the

leakage inductance on the primary of the transformer

causes a voltage spike to occur on the SW pin. The height

of this spike must not exceed 40V, even though the

absolute maximum rating of the SW Pin is 50V. The 50V

absolute maximum rating is a DC blocking voltage speci-

fication, which assumes that the current in the power NPN

is zero. Figure 4 shows the SW voltage waveform for the

circuit of Figure 1(LT3468). Note that the absolute maxi-

mum rating of the SW pin is not exceeded. Figure 5 shows

theSWvoltagewaveformforthecircuitofFigure2(LT3468-

1). Again, the absolute maximum rating of the SW pin is

V

V_SW

10V/DIV

100ns/DIV

3468 G19

Figure 5. LT3468-1 SW Voltage Waveform

not compromised. Make sure to check the SW voltage

waveform with V_OUTnear the target output voltage, as this

is the worst case condition for SW voltage.

It is important not to minimize the leakage inductance to

a very low level. Although this would result in a very low

leakage spike on the SW pin, the parasitic capacitance of

the transformer would become large. This will adversely

effect the charge time of the photoflash circuit.

V_IN= 5V

V_OUT= 320V

Linear Technology has worked with several leading mag-

netic component manufacturers to produce pre-designed

flyback transformers for use with the LT3468/LT3468-1.

Table 2 shows the details of several of these transformers.

V_SW

10V/DIV

100ns/DIV

3468 G18

Figure 4. LT3468 SW Voltage Waveform

Table 2. Pre-Designed Transformers - Typical Specifications Unless Otherwise Noted.

SIZE

L

R

(mΩ)

R

SEC

(Ω)

PRI

LPRI-LEAKAGE

PRI

FOR USE WITH

TRANSFORMER NAME (W × L × H) mm (µH)

(nH)

N

VENDOR

LT3468

LT3468-1

SBL-5.6-1

SBL-5.6S-1

5.6 × 8.5 × 4.0

5.6 × 8.5 × 3.0

10

24

200 Max

400 Max

10.2

103

305

26

55

Kijima Musen

Hong Kong Office

852-2489-8266 (ph)

kijimahk@netvigator.com (email)

LT3468

LT3468-1

LDT565630T-001

LDT565630T-002

5.8 × 5.8 × 3.0

6

14.5

200 Max

500 Max

10.4 100 Max 10 Max

10.2 240 Max 16.5 Max

TDK

Chicago Sales Office

(847) 803-6100 (ph)

www.components.tdk.com

LT3468/LT3468-1

LT3468-1

T-15-089

T-15-083

6.4 × 7.7 × 4.0

8.0 × 8.9 × 2.0

12

20

400 Max

500 Max

10.2 211 Max 27 Max

10.2 675 Max 35 Max

Tokyo Coil Engineering

Japan Office

0426-56-6336 (ph)

www.tokyo-coil.co.jp

34681i

8

LT3468/LT3468-1

U

W

U U

APPLICATIO S I FOR ATIO

Capacitor Selection

For the circuit of Figure 1 with V_INof 5V, V_PK-Ris 371V and

I_PK-SECis 137mA. The GSD2004S dual silicon diode is

recommended for most LT3468/LT3468-1 applications.

Another option is to use the BAV23S dual silicon diodes.

Toshiba makes a dual diode named 1SS306 which also

meets all the requirements. Table 3 shows the various

diodes and relevant specifications. Use the appropriate

number of diodes to achieve the necessary reverse break-

down voltage.

For the input bypass capacitor, a high quality X5R or X7R

type should be used. Make sure the voltage capability of

the part is adequate.

Output Diode Selection

The rectifying diode(s) should be low capacitance type

with sufficient reverse voltage and forward current rat-

ings. The peak reverse voltage that the diode(s) will see is

approximately:

SW Pin Clamp Diode Selection

The diode D2 in Figure 1 is needed to clamp the SW node.

Due to the new control scheme of the LT3468/LT3468-1,

the SW node may go below ground during a switch cycle.

The clamp diode prevents the SW node from going too

far below ground. The diode is required for proper opera-

tion of the circuit. The recommended diode should be a

Schottkydiodewithatleasta500mApeakforwardcurrent

capability. Reversevoltageratingshouldbe40Vorhigher.

Table 4 shows various recommended clamping diodes.

V

_PK−R= V_OUT+ N • V

(

)

IN

The peak current of the diode is simply:

1.4

I_PK−SEC

=

(LT3468)

N

0.7

N

I_PK−SEC

(LT3468-1)

Table 3. Recommended Output Diodes

MAX REVERSE VOLTAGE MAX FORWARD CONTINUOUS CURRENT

CAPACITANCE

(pF)

PART

(V)

(mA)

VENDOR

GSD2004S

(Dual Diode)

2x300

225

5

3

Vishay

(402) 563-6866

www.vishay.com

BAV23S

(Dual Diode)

2x250

225

100

Philips Semiconductor

(800) 234-7381

www.philips.com

1SS306

Toshiba

(Dual Diode)

(949) 455-2000

www.semicon.toshiba.co.jp

Table 4. Recommended Clamp Diodes

MAX REVERSE VOLTAGE

PART

(V)

VENDOR

ZHCS400

40

Zetex

(631) 360-2222

www.zetex.com

B0540W

40

Diodes Inc.

(805) 446-4800

www.diodes.com

34681i

9

LT3468/LT3468-1

U

W

U U

APPLICATIO S I FOR ATIO

Board Layout

all high voltage nodes in order to meet breakdown voltage

requirements for the circuit board. It is imperative to keep

theelectricalpathformedbyC1, theprimaryofT1, andthe

LT3468/LT3468-1 as short as possible. If this path is

haphazardly made long, it will effectively increase the

leakage inductance of T1, which may result in an overvolt-

age condition on the SW pin.

The high voltage operation of the LT3468/LT3468-1 de-

mands careful attention to board layout. You will not get

advertised performance with careless layout. Figure 6

showstherecommendedcomponentplacement.Keepthe

area for the high voltage end of the secondary as small as

possible. Also note the larger than minimum spacing for

V

IN

C1

R1

D1

(DUAL DIODE)

DONE

CHARGE

+

C

4

5

3

2

1

•

OUT

PHOTOFLASH

CAPACITOR

T1

•

D2

3468 F01

Figure 6. Suggested Layout: Keep electrical path formed by C1, Transformer Primary and LT3468/LT3468-1 short.

34681i

10

LT3468/LT3468-1

U

PACKAGE DESCRIPTIO

S5 Package

5-Lead Plastic SOT-23

(Reference LTC DWG # 05-08-1633)

0.62

MAX

0.95

REF

2.80 – 3.10

(NOTE 4)

1.22 REF

1.50 – 1.75

(NOTE 4)

2.60 – 3.00

1.4 MIN

3.85 MAX 2.62 REF

PIN ONE

0.25 – 0.50

TYP 5 PLCS

NOTE 3

RECOMMENDED SOLDER PAD LAYOUT

PER IPC CALCULATOR

0.95 BSC

0.90 – 1.30

0.20 BSC

DATUM ‘A’

0.00 – 0.15

0.90 – 1.45

0.35 – 0.55 REF

1.90 BSC

0.09 – 0.20

(NOTE 3)

NOTE:

S5 SOT-23 0502

1. DIMENSIONS ARE IN MILLIMETERS

2. DRAWING NOT TO SCALE

3. DIMENSIONS ARE INCLUSIVE OF PLATING

ATTENTION: ORIGINAL SOT23-5L PACKAGE.

MOST SOT23-5L PRODUCTS CONVERTED TO THIN SOT23

PACKAGE, DRAWING # 05-08-1635 AFTER APPROXIMATELY

APRIL 2001 SHIP DATE

4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR

5. MOLD FLASH SHALL NOT EXCEED 0.254mm

6. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ)

34681i

11

LT3468/LT3468-1

U

TYPICAL APPLICATIO S

LT3468 Photoflash Circuit uses Tiny 3mm Tall Transformer

T1

Charge Time

D1

1:10.4

V

10

9

8

7

6

5

4

3

2

1

0

IN

320V

2.5V TO 8V

5, 6

7, 8

4

1

C1

4.7µF

+

C

OUT

PHOTOFLASH

CAPACITOR

5

1

V

SW

IN

R1

100k

D2

LT3468

C

OUT

= 100µF

2

3

4

DONE

GND

CHARGE

C

OUT

= 50µF

C1: 4.7µF, X5R OR X7R, 10V

T1: TDK PART# LDT565630T-001, L = 6µH, N = 10.4

D1: VISHAY GSD2004S DUAL DIODE CONNECTED IN SERIES

D2: ZETEX ZHCS400 OR EQUIVALENT

R1: PULL UP RESISTOR NEEDED IF DONE PIN USED

PRI

2

3

4

5

V

6

7

8

9

3468 TA03

(V)

IN

3468 TA05

LT3468-1 Photoflash Circuit uses Tiny 3mm Tall Transformer

T1

Charge Time

D1

1:10.2

V

IN

320V

10

9

8

7

6

5

4

3

2

1

0

2.5V TO 8V

5

8

4

1

C1

4.7µF

+

C

OUT

PHOTOFLASH

CAPACITOR

5

1

V

SW

IN

R1

100k

D2

LT3468-1

C

= 50µF

OUT

2

3

4

DONE

GND

CHARGE

C

OUT

= 20µF

C1: 4.7µF, X5R OR X7R, 10V

T1: TDK PART# LDT565630T-002, L = 14.5µH, N = 10.2

D1: VISHAY GSD2004S DUAL DIODE CONNECTED IN SERIES

D2: ZETEX ZHCS400 OR EQUIVALENT

R1: PULL UP RESISTOR NEEDED IF DONE PIN USED

PRI

2

3

4

5

6

7

8

9

3468 TA04

V

IN

(V)

3468 TA06

RELATED PARTS

PART NUMBER

DESCRIPTION

COMMENTS

LTC3407

Dual 600mA (I ), 1.5MHz, Synchronous Step-Down DC/DC 96% Efficiency, V : 2.5V to 5.5V, V

: 0.6V, I : 40µA,

OUT(MIN) Q

OUT

IN

Converter

I : <1µA, MS10E

SD

LT3420/LT3420-1

LTC3425

1.4A/1A, Photoflash Capacitor Chargers with

Automatic Top-Off

Charges 220µF to 320V in 3.7 seconds from 5V,

V : 2.2V to 16V, I : 90µA, I : <1µA, MS10

IN

Q

SD

5A I , 8MHz, Multi-Phase Synchronous Step-Up DC/DC

95% Efficiency, V : 0.5V to 4.5V, V

: 5.25V, I : 12µA,

OUT(MIN)

SW

IN

Q

Converter

I : <1µA, QFN-32

SD

LTC3440/LTC3441

600mA/1A (I ), Synchronous Buck-Boost DC/DC Converter 95% Efficiency, V : 2.5V to 5.5V, V

: 2.5V to 5.5V,

OUT(MIN)

OUT

IN

I : 25µA, I : <1µA, MS-10, DFN-12

Q

SD

34681i

LT/TP 1003 1K • PRINTED IN USA

12 ^{LinearTechnology Corporation}

1630 McCarthy Blvd., Milpitas, CA 95035-7417

●

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

LINEAR TECHNOLOGY CORPORATION 2003


型号：	LT3468ES5-1
厂家：	Linear
描述：	Photoflash Capacitor Charger in ThinSOT 照片FL灰电容充电器采用ThinSOT 模拟IC 信号电路光电二极管
文件：	总12页 (文件大小：303K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LT3468ES5-1 [Linear]

相关型号：

LT3468ES5-1#TR

LT3468ES5-1#TRMPBF

LT3468ES5-1#TRPBF

LT3468ES5-2

LT3468ES5-2#PBF

LT3468ES5-2#TR

LT3468ES5-2#TRM

LT3468ES5-2#TRMPBF

LT3468ES5-2#TRPBF

LT3468_15

LT3469

LT3469ETS8