LTC3531ES6-3.3#TRPBF

LTC3531/

LTC3531-3.3/LTC3531-3

200mA Buck-Boost

Synchronous DC/DC

Converters

U

FEATURES

DESCRIPTIO

■

Regulated Output with Input Above, Below or Equal

The LTC^®3531/LTC3531-3.3/LTC3531-3 are synchronous

buck-boost DC/DC converters that operate from input

voltages above, below or equal to the output voltage. The

topology incorporated in the ICs provides a continuous

transfer through all operating modes, making the product

ideal for single cell Li-Ion and multicell alkaline or nickel

applications. The converters operate in Burst Mode, mini-

mizing solution footprint and component count as well as

providing high conversion efﬁciency over a wide range of

load currents.

to the Output

■

Single Inductor

■

Up to 90% Efﬁciency

■

V Range: 1.8V to 5.5V

IN

■

200mA at 3.3V

from 3.6V Input

OUT

125mA at 3V

from 2.5V Input

OUT

Fixed V

Versions (TSOT, DFN): 3.3V, 3V

OUT

Adjustable V

Version (DFN): 2V to 5V

OUT

Burst Mode^®Operation, No External Compensation

Ultra Low Quiescent Current: 16μA, Shutdown

Current <1μA

Thedevicesincludetwo0.5ΩN-channelMOSFETswitches

and two P-channel switches (0.5Ω, 0.8Ω). Quiescent

current is typically 16μA, making the parts ideal for bat-

tery power applications. Other features include a <1μA

shutdown current, current limiting, thermal shutdown

and output disconnect. The parts are offered in a 6-pin

ThinSOT^TMpackage for ﬁxed voltage versions or a 3mm ×

3mm DFN package for ﬁxed and adjustable versions.

■

Only 3 External Components Required

(Fixed Voltage Versions)

Short-Circuit Protection

Output Disconnect in Shutdown

Available in 6-Pin ThinSOT and 3mm × 3mm DFN

Packages

■

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APPLICATIO S

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

Burst Mode is a registered trademark of Linear Technology Corporation.

ThinSOT is a trademark of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

Protected by U.S. Patents including 6166527.

■

Handheld Instruments

■

MP3 Players

■

Handheld computers

PDA/GPS

■

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TYPICAL APPLICATIO

Efﬁciency vs V_IN

100

10μH

95

90

85

80

75

70

65

60

BOOST

MODE

SW1

SW2

V

IN

OUT

BUCK

MODE

3.1V TO

4.2V

V

OUT

3.3V

IN

160mA

LTC3531-3.3

4SW

+

Li-Ion

2.2μF

10μF

MODE

SHDN

GND

3531 TA01a

ON OFF

3.3V

4

AT 100mA

OUT

3.5

1.5

2

2.5

3

4.5

5

5.5

INPUT VOLTAGE (V)

3531 TA01b

3531fb

1

LTC3531/

LTC3531-3.3/LTC3531-3

W W U W

ABSOLUTE AXI U RATI GS

(Note 1)

VIN, VOUT, SW1, SW2, SHDN Voltage...........–0.3 to 6V

SW1, SW2 Voltage, <100ns Pulse ..................–0.3 to 7V

Operating Temperature Range (Notes 2,3)–40°C to 85°C

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

Lead Temperature (TS6, Soldering, 10 sec).......... 300°C

U

W

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PACKAGE/ORDER I FOR ATIO

TOP VIEW

SW1

1

2

3

4

8

7

6

5

PGND

SW2

V

IN

SW2 1

6 SW1

9

GND

V

OUT

5 V

IN

GND, PGND 2

SHDN

FB*

V

OUT

3

4 SHDN

S6 PACKAGE

DD PACKAGE

6-LEAD PLASTIC TSOT-23

8-LEAD (3mm × 3mm) PLASTIC DFN

T

= 125°C, θ = 102°C/W

T

= 125°C, θ = 43°C/W

JA

JMAX

JA

JMAX

EXPOSED PAD IS GND (PIN 9), MUST BE SOLDERED TO PCB

*NC FOR LTC3531-3.3V, LTC3531-3.0V.

ORDER PART NUMBER

S6 PART MARKING

ORDER PART NUMBER

DD PART MARKING

LTC3531ES6-3.3

LTC3531ES6-3

LTBWM

LTCBK

LTC3531EDD

LTC3531EDD-3.3

LTC3531EDD-3

LBVC

LBWH

LCBV

Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF

Lead Free Part Marking: http://www.linear.com/leadfree/

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

The ● denotes the speciﬁcations which apply over the full operating

ELECTRICAL CHARACTERISTICS

temperature range, otherwise speciﬁcations are at T_A= 25°C. V_IN= 3.6V V_OUT= 3.3V unless otherwise noted.

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

V

IN

Minimum Startup Voltage

Regulation

●

1.65

1.8

V

OUT

Output Voltage (3.3V Version)

Output Voltage (3V Version)

FB Voltage (Adj Version)

FB Input Current (Adj Version)

Operating Current

No Load

●

3.25

2.95

1.20

3.32

3.02

1.225

1

3.39

3.09

1.25

50

V

FB

= 1.225V

nA

Quiescent Current in Sleep:

V

OUT

V

= 5V, V

= 3.6V, FB = 1.3V

= 0V

OUT

16

6

30

10

μA

IN

OUT

V

= 3.6V

OUT

Shutdown Current

V

= 0V, V

1

μA

SHDN

IN

Switch Performance

NMOS Switch Leakage

PMOS Switch Leakage

Switches B and C

Switches A and D

0.2

0.5

2

μA

Ω

NMOS B, C R

V

= 5V

DSON

IN

PMOS A R

Ω

3531fb

2

LTC3531/

LTC3531-3.3/LTC3531-3

ELECTRICAL CHARACTERISTICS

The ● denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T_A= 25°C. V_IN= 3.6V V_OUT= 3.3V unless otherwise noted.

PARAMETER

CONDITIONS

MIN

TYP

0.8

MAX

UNITS

Ω

PMOS D R

(3.3V Version or Adjustable Version set to 3.3V)

(3V Version)

V

= 3.1V

= 2.8V

DSON

OUT

0.9

Ω

Peak Current Limit

L = 10μH, V = 5V

295

0.4

365

460

1.4

1

mA

IN

SHDN

Input Threshold

1

V

mV

μA

SHDN

Hysteresis

60

Leakage Current

V

0.01

SHDN

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

Note 2: This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions. Junction

temperature will exceed 125°C when overtemperature protection is active.

Continuous operation above the speciﬁed maximum operating junction

temperature may result in device degradation or failure.

Note 3: The LTC3531 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.

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TYPICAL PERFOR A CE CHARACTERISTICS ^T_A^{= 25°C unless otherwise speciﬁed.}

Maximum I_OUTvs V_IN

(3.3V Version)

I_PEAK, I_VALLEY, I_ZEROvs V_IN

Sleep Currents

450

400

350

300

250

200

150

100

50

20

18

16

14

12

10

8

350

300

L = 10μH

OUT

L = 10μH

V

= 3.3V

I

VIN

I

PEAK

250

200

150

100

50

I

VALLEY

6

I

VOUT

4

2

I

ZERO

0

2

2.5

3.5

(V)

5.5

3

3.5

(V)

1.5

3

4

4.5

5

1.5

5

5.5

2

2.5

4

4.5

1.5

5

2

2.5

3

3.5

(V)

4

4.5

5.5

V

IN

3531 G01

3531 G02

3531 G03

V_OUTRipple vs C_OUT

(3.3V Version)

Load Regulation vs C_OUT

(3.3V Version)

I_INShort Circuit vs V_IN

180

160

140

100

90

80

70

60

50

40

30

20

10

0

3.40

3.35

3.30

3.25

3.20

3.15

10μF

120

100

80

22μF

47μF

60

40

20

V

= 3.6V

50mA LOAD

IN

0

1

10

100

0.1

3.5

(V)

4

5

1000

1.5

2

2.5

3

4.5

5

5.5

1.5

3.5

(V)

4.5

2

2.5

3

4

5.5

V

LOAD CURRENT (mA)

V

IN

3521 G06

3531 G04

3531 G05

3531fb

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LTC3531/

LTC3531-3.3/LTC3531-3

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TYPICAL PERFOR A CE CHARACTERISTICS

T_A= 25°C unless otherwise speciﬁed.

Start-Up into Resistive Load

L = 10μH

Burst Frequency vs Load

(3.3V Version)

V_OUTRegulation vs Temperature

(3.3V Version)

30

28

26

24

22

20

18

16

14

12

10

1000

100

10

3.350

3.325

3.300

3.275

V

LOAD

= 3.6V

IN

L = 10μH

I

= 10mA

C

= 10μF

OUT

50mA

10mA

5mA

1mA

1

0.5mA

0.1

3.250

1.5

3.5

(V)

4.5

5

2

2.5

3

4

5.5

–40 –20

0

20

40

60

80 100

1.5

2

2.5

3

3.5

(V)

4

4.5

5

5.5

V

IN

TEMPERATURE (°C)

V

IN

3531 G08

3531 G07

3531 G09

SHDN Pin Threshold and

Hysteresis

Switch On Resistances

I_PEAK, I_VALLEYvs Temperature

1

0.9

0.8

0.7

1000

900

800

700

600

500

400

350

300

250

V

= 5V

IN

OUT

I

PEAK

= 3.3V

D (PMOS)

OPERATING

SHUTDOWN

I

VALLEY

200

150

A (PMOS)

2.5V

3.3V

IN

OUT

10μH

100

50

0

0.6

0.5

B,C (NMOS)

I

ZERO

–40

0

20

40

60

80 100

–40

0

20

40

60

80 100

–20

0

40

–40

60

80 100

20

TEMPERATURE (°C)

3531 G12

3531 G10

3531 G11

3531fb

4

LTC3531/

LTC3531-3.3/LTC3531-3

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TYPICAL PERFOR A CE CHARACTERISTICS

T_A= 25°C unless otherwise speciﬁed.

Buck Mode at 5V_IN,

3.3V_OUT200mA

Buck Mode at 5V_IN,

3.3V_OUT100mA

SW1

5V/DIV

SW1

5V/DIV

SW2

5V/DIV

SW2

5V/DIV

V

(AC)

V

(AC)

OUT

50mV/DIV

OUT

50mV/DIV

I

L

200mA/DIV

3531 G13

3531 G14

L = 10μH

= 22μF

5μs/DIV

L = 10μH

C = 22μF

OUT

5μs/DIV

C

OUT

4 Switch Mode Waveforms at

3.6V_IN, 3.3V_OUT200mA

Buck Mode Waveforms at 5V_IN,

3.3V_OUT20mA

SW1

5V/DIV

SW1

5V/DIV

SW2

5V/DIV

SW2

5V/DIV

V

(AC)

V

(AC)

OUT

50mV/DIV

OUT

50mV/DIV

I

L

200mA/DIV

3531 G15

3531 G16

L = 10μH

= 22μF

5μs/DIV

L = 10μH

C = 22μF

OUT

5μs/DIV

C

OUT

4 Switch Mode Waveforms at

3.6V_IN, 3.3V_OUT100mA

4 Switch Mode Waveforms at

3.6V_IN, 3.3V_OUT20mA

SW1

5V/DIV

SW1

5V/DIV

SW1

SW2

5V/DIV

V

(AC)

50mV/DIV

V

(AC)

50mV/DIV

OUT

V

I

(AC)

OUT

I

L

I

L

200mA/DIV

L

3531 G17

3531 G18

L = 10μH

= 22μF

5μs/DIV

L = 10μH

C = 22μF

OUT

5μs/DIV

C

OUT

3531fb

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LTC3531/

LTC3531-3.3/LTC3531-3

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TYPICAL PERFOR A CE CHARACTERISTICS

T_A= 25°C unless otherwise speciﬁed.

Boost Mode Waveforms at

2.5V_IN, 3.3V_OUT100mA

Boost Mode Waveforms at

2.5V_IN, 3.3V_OUT20mA

SW1

5V/DIV

SW1

5V/DIV

SW2

5V/DIV

SW2

5V/DIV

V

(AC)

V

(AC)

OUT

50mV/DIV

OUT

50mV/DIV

I

L

200mA/DIV

3531 G19

3531 G20

L = 10μH

= 22μF

5μs/DIV

L = 10μH

C = 22μF

OUT

5μs/DIV

C

OUT

Start-Up into 50mA Load at

3.3 V_OUT(Shows Start, Buck,

Then 4sw Modes)

Shorted Output

SW1

5V/DIV

SW2

5V/DIV

V

OUT

1V/DIV

V

(AC)

200mA/DIV

OUT

50mV/DIV

I

L

I

L

200mA/DIV

3531 G21

3531 G22

L = 10μH

OUT

V_IN= 5

1μs/DIV

25μs/DIV

C

= 22μF

3.6V_IN, 3.3V_OUTLoad Step

200mA to 80mA

SW1 and SW2 Close-Up in Four

Switch Mode

100mA LOAD

SW1

2V/DIV

20mA LOAD

I

L

200mA/DIV

V

(AC)

OUT

20mV/DIV

SW2

2V/DIV

3531 G23

3531 G24

C

OUT

= 22μF

25μs/DIV

V_IN= 3.6V

V_OUT= 3.3V

200ns/DIV

3531fb

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LTC3531/

LTC3531-3.3/LTC3531-3

U

PI FU CTIO S ^{ThinSOT/DFN Packages}

SW2(Pin1/Pin7):Buck-BoostSwitchPinWhereInternal

V

IN

(Pin 5/Pin 2): Input Supply Pin for the Buck-Boost

Switches C and D are Connected. An optional Schottky

Converter. A minimum 2.2μF Ceramic Capacitor should

diode can be connected from SW2 to V

for a moderate

be placed between V and GND.

OUT

IN

efﬁciency improvement. Minimize trace length to keep

EMI down.

FB (NA/Pin 5): Feedback Pin for the Adjustable Version.

Connect the resistor divider tap here. The output voltage

can be adjusted from 2V to 5V.

GND (Pin 2/Pin 3): Signal Ground for the IC.

PGND (Pin 2/Pin 8): Power Ground for the IC. (Shared

on ThinSOT version)

R2

R1

⎛

⎝

⎞

V_OUT= 1.225 1+

⎜

⎟

⎠

V

(Pin3/Pin6):OutputoftheBuck-BoostSynchronous

OUT

SW1 (Pin 6/Pin 1): Buck-Boost Switch Pin Where Internal

Switches A and B are Connected. Connect the inductor

from SW1 to SW2.

Rectiﬁer. A ﬁlter capacitor is placed from V

to GND.

OUT

A ceramic bypass capacitor is recommended as close to

the V and GND pins as possible.

OUT

Exposed Pad (Pin 9, DFN): Solder to PCB ground for

optimal thermal performance.

SHDN (Pin 4/Pin 4): External Shutdown Pin. An applied

voltage of < 0.4V shuts down the converter. A voltage

above >1.4V will enable the converter.

3531fb

7

LTC3531/

LTC3531-3.3/LTC3531-3

W

BLOCK DIAGRA

SW1

SW2

SW A

SW D

V

IN

OUT

GATE DRIVERS

AND

ANTICROSS

CONDUCTION

I

/I

ZERO VALLEY

SW B

SW C

DETECT

V

PEAK

BEST

V

CURRENT

IN

V

BEST

LIMIT

AND

MODE DETECT

365mA

BUCK, 4SW,

BOOST

V

OUT

STATE

MACHINE

AND

LOGIC

V

IN

R2

1.225V V

R1

REF

UVLO

1.65V

FB

V

OUT

COMPARATOR

NOT BONDED

FOR 3.3V AND

3V VERSIONS

THERMAL

SHUTDOWN

SHDN

SHUTDOWN

3531 BD

INTERNAL

R1 AND R2

PGND

GND

COMBINED

FOR TSOT

DISABLED

FOR ADJ VERSION

3531fb

8

LTC3531/

LTC3531-3.3/LTC3531-3

U

OPERATIO

occurs, C is turned off, D is turned on and current is deliv-

The LTC3531, LTC3531-3.3 and LTC3531-3 synchro-

nous buck-boost converters utilize a Burst Mode control

technique to achieve high efﬁciency over a wide dynamic

range of load currents. A 2% accurate comparator is

ered to the output capacitor (V – V

is applied across

IN

OUT

the inductor). Inductor current falls when D is on, until an

isdetected.TerminatingatI ,ratherthanI

I

,

ZERO

VALLEY

results in an increased load current capability for a given

peakcurrent.ThisACthenADswitchsequenceisrepeated

until the output is pumped above its regulation voltage, a

used to monitor the output voltage. If V

is above its

OUT

programmedreferencethresholdnoswitchingoccursand

only quiescent current is drawn from the power source

ﬁnal I

(I

OUT

is detected, and the part returns to sleep mode

(sleep mode). When V

drops below the reference

ZERO

OUT

is ignored and I

is used in all modes once

threshold the IC “wakes up”, switching commences, and

the output capacitor is charged. The value of the output

capacitor, the load current, and the comparator hysteresis

(~1%) determines the number of current pulses required

to pump-up the output capacitor before the part returns

to sleep.

VALLEY

ZERO

V

is above its programmed value).

4-Switch Mode

If (V – 400mV) < ~V < (V + 800mV), the LTC3531

OUT

IN

operates in 4-switch step-up/down mode. Returning to

Figure 1 (center) when V falls below its regulation volt-

In order to determine the best operating mode for the

converter, the LTC3531 contains a second comparator

OUT

age, switches A and C are turned on and current is ramped

until I is detected. As with Boost Mode operation, C

that monitors the relative voltage difference between V

PEAK

IN

is then turned off, D is turned on and current is delivered

to the output. When A and D are on, the inductor current

and V . Input and output voltages in the various modes

OUT

as well as typical inductor currents are shown in Figure 1.

Regions of the current waveforms where switches A and

D are on provide the highest efﬁciency since energy is

transferred directly from the input source to the output.

slope is dependant on the relationship between V , V

,

IN OUT

and the R

of the switches. In 4-switch mode, a t

DSON

OFF

timer (approximately 3μs) is used to terminate the AD

pulse. Once the t timer expires, switch A is turned off,

OFF

B is turned on and inductor current is ramped down (V

Boost Mode

OUT

is applied across the inductor) until I

is detected.

VALLEY

If V is ~400mV below V , the LTC3531 operates in

IN

OUT

This sequence is repeated until the output is regulated,

BD switches are turned on, and a ﬁnal I is detected.

boost or step-up mode. Referring to Figure 1 (left side)

when V falls below its regulation voltage, switches A

ZERO

OUT

Anticross conduction circuitry in all modes ensures the

P-channelMOSFETandN-channelMOSFETswitchpairs(A

and B or D and C) are never turned on simultaneously.

and C are turned on (V is applied across the inductor)

IN

and current is ramped until I

is detected. When this

PEAK

V

IN

V

OUT

V

IN

V

OUT

A

SW1

B

D

V

IN

L

SW2

C

I

MAX

I

PEAK

t

OFF

I

VALLEY

I

ZERO

AC AD AC AD

BOOST MODE

AC AD BD AC AD

4SW MODE

BD AC

AD

BD

AD BD AD BD

BUCK MODE

3531 F01

Figure 1. Voltage and Current Waveforms

3531fb

9

LTC3531/

LTC3531-3.3/LTC3531-3

U

OPERATIO

Buck Mode

thresholdisreached,theLTC3531willtransferthroughthe

required modes until V is brought into regulation.

OUT

If V is ~800mV above V , the LTC3531 operates in

IN

OUT

buck or step-down mode. The higher offset between V

Due to propagation delays in the sense circuitry, the

magnitudes of the I , I , and I currents may

IN

and V

(800mV) is required to ensure sufﬁcient mag-

OUT

PEAK VALLEY

ZERO

netizing voltage across the inductor when the R

shift depending on V , V

and operating mode.

DSONS

IN OUT

are taken into account. At the beginning of a buck mode

OTHER LTC3531 FEATURES

Shutdown: The part is shut down by pulling SHDN below

0.4V, and made active by pulling the pin up to V or V

cycle (Figure 1 right side) switches A and D are turned

on (V – V

is applied across the inductor), current

OUT

IN

is delivered to the output and ramped up until I

is

PEAK

.

OUT

IN

detected. When this occurs, A is turned off, B is turned

on and inductor current falls (–V across the induc-

Note that SHDN an be driven above V or V , as long

IN

OUT

as it is limited to less than 6V.

tor) until an I

is detected. This AD then BD switch

VALLEY

Output Disconnect and Inrush Limiting: The LTC3531

sequence is repeated until the output is pumped above

is designed to allow true output disconnect by opening

its regulation voltage, a ﬁnal I

part returns to sleep mode.

is detected, and the

ZERO

both P-channel MOSFET rectiﬁers. This allows V

to go

OUT

to zero volts during shutdown, drawing no current from

the input source. It also provides inrush current limiting

at turn-on, minimizing surge currents seen by the input

supply.

Start-Up Mode

Before V

reaches approximately 1.6V, the D switch is

OUT

disabled and its body diode is used to transfer current to

the output capacitor. In start-up mode, the I /I

Thermal Shutdown: If the die temperature reaches ap-

proximately 150°C, the part will go into thermal shut-

down and all switches will be turned off. The part will be

enabled again when the die temperature has dropped by

10°C (nominal). To deliver the power that the LTC3531

is capable of, it is imperative that a good thermal path be

provided to dissipate the heat generated within the pack-

age. It is recommended that multiple vias in the printed

circuit board be used to conduct heat away from the IC

and into a copper plane with as much area as possible.

SolderingtheExposedPadtotheGNDplane(DFNversion)

is recommended to improve thermal performance.

VALLEY ZERO

sensecircuitisdisabledandanalternatealgorithmisused

to control inductor current. When the LTC3531 is brought

out of shutdown (assuming V

is discharged) switches

OUT

A and C are turned on until the inductor current reaches

. The AC switches are then turned off and inductor

I

PEAK

current ﬂows to the output through the B switch and D

body diode. The period for the B switch/D body diode is

controlled by the t timer to ~800nS. This sequence of

OFF

PEAK

AC switch-on to I

then B switch and D body diode for

~800ns is repeated until V

reaches ~1.6V. Once this

OUT

3531fb

10

LTC3531/

LTC3531-3.3/LTC3531-3

U

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APPLICATIO S I FOR ATIO

Component Selection

ductor value with a >500mA current rating and <400mΩ

DCR is recommended. For applications where radiated

noise is a concern, a toroidal or shielded inductor can be

used. Table 2 contains a list of inductor manufacturers.

Only three power components are required to

complete the design of the buck-boost converter, V

programming resistors are needed for the adjustable

version. The high operating frequency and low peak

currents of the LTC3531 allow the use of low value, low

proﬁle inductors and tiny external ceramic capacitors.

OUT

Capacitor Selection

Thebuck-boostconvertorrequirestwocapacitors.Ceramic

X5R types will minimize ESL and ESR while maintaining

capacitance at rated voltage over temperature. The V

IN

Inductor Selection

capacitor should be at least 2.2μF. The V

capacitor

OUT

Forbestefﬁciency,chooseaninductorwithhighfrequency

core material, such as ferrite, to reduce core loses. The

inductor should have low DCR (DC resistance) to reduce

the I R losses, and must be able to handle the peak

inductor current without saturating. A 10μH to 22μH in-

shouldbebetween4.7μFand22μF. Alargeroutputcapaci-

tor should be used if lower peak to peak output voltage

rippleisdesired.Alargeroutputcapacitorwillalsoimprove

2

load regulation on V . See Table 3 for a list of capacitor

OUT

manufacturers for input and output capacitor selection.

Table 3. Capacitor Vendor Information

Table 2. Inductor Vendor Information

Supplier

AVX

Series

X5R

Phone

Website

Supplier Series

COEV DN4835

Phone

Website

(803) 448-9411

www.avxcorp.com

(800) 227-7040

(847) 639-6400

www.coev.net

www.coilcraft.com

Murata

X5R

USA: (814) 237-1431 www.murata.com

(800) 831-9172

Coilcraft MSS4020

LPO3310

DS1608

Sanyo

POSCAP (619) 661-6322

www.sanyovideo.com

www.taiyo-yuden.com

www.component.tdk.com

Murata

Sumida

Toko

LQH43CN

LQH32CN

USA: (814) 237-1431

(800) 831-9172

www.murata.com

www.sumida.com

www.tokoam.com

Taiyo Yuden X5R

TDK X5R

(408) 573-4150

(847) 803-6100

CDRH4D18

CDRH3D16/HP Japan: 81-3-3607-5111

USA: (847) 956-0666

D312C

D412C

DB320C

(847) 297-0070

3531fb

11

LTC3531/

LTC3531-3.3/LTC3531-3

U

W

U U

APPLICATIO S I FOR ATIO

SHUTDOWN

C

OUT

C

IN

V

OUT

IN

L

GND

V

– 3

GND

4 – SHDN

OUT

5 – V

IN

GND – 2

SW2 – 1

6 – SW1

SOT PIN-OUT

Recommended Layout (SOT Versions)

3531fb

12

LTC3531/

LTC3531-3.3/LTC3531-3

U

TYPICAL APPLICATIO

5V/Li-Ion to 3.3V with ThinSOT (3.3V Version)

95

100

10

1

4.4V

5V

10μH

IN

90

85

IN

SW1

SW2

V

OUT

IN

3.1V TO

5V

3.3V

V

OUT

IN

160mA

3.6V

IN

LTC3531-3.3

+

–

80

75

3.1V

2.2μF

10μF

5V/Li-Ion

IN

SHDN

GND

3531 TA02a

POWER LOSS AT 3.6V

IN

70

65

ON OFF

0.1

1000

0.1

1

10

100

LOAD CURRENT (mA)

3531 TA02b

2 AA Alkaline to 3V with ThinSOT (3V Version)

90

85

100

10

1

10μH

SW1

SW2

V

IN

OUT

80

2.5V

IN

V

1.8V TO

3.2V

3V

IN

OUT

+

–

80mA

3.2V

IN

LTC3531-3

75

70

2 x AA

ALKALINE

2.2μF

10μF

1.8V

IN

+

–

SHDN

GND

POWER LOSS AT 3.2V

IN

3531 TA03a

65

60

ON OFF

0.1

1

10

100

1000

LOAD CURRENT (mA)

3531 TA03b

USB to 5V with 3 × 3 DFN (Adjustable Version)

95

90

100

10

1

10μH

EFFICIENCY

SW1

SW2

USB

4.35V TO

5.25V

V

OUT

85

V

5V

IN

OUT

200mA

R2

4.7μF

LTC3531

1M

80

75

2.2μF

10μF

FB

POWER LOSS

R1

324k

SHDN

GND

1Ω

3531 TA04a

70

65

ON OFF

0.1

1000

0.1

1

10

100

LOAD CURRENT (mA)

3531 TA04b

3531fb

13

LTC3531/

LTC3531-3.3/LTC3531-3

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

1.00 MAX

0.20 BSC

0.01 – 0.10

DATUM ‘A’

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

3531fb

14

LTC3531/

LTC3531-3.3/LTC3531-3

U

PACKAGE DESCRIPTIO

DD Package

8-Lead Plastic DFN (3mm × 3mm)

(Reference LTC DWG # 05-08-1698)

0.675 0.05

3.5 0.05

2.15 0.05 (2 SIDES)

1.65 0.05

PACKAGE

OUTLINE

0.25 0.05

0.50

BSC

2.38 0.05

(2 SIDES)

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS

R = 0.115

0.38 0.10

TYP

5

8

3.00 0.10

(4 SIDES)

1.65 0.10

(2 SIDES)

PIN 1

TOP MARK

(NOTE 6)

(DD) DFN 1203

4

1

0.25 0.05

0.75 0.05

0.200 REF

0.50 BSC

2.38 0.10

(2 SIDES)

0.00 – 0.05

BOTTOM VIEW—EXPOSED PAD

NOTE:

1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)

2. DRAWING NOT TO SCALE

3. ALL DIMENSIONS ARE IN MILLIMETERS

4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE

MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE

5. EXPOSED PAD SHALL BE SOLDER PLATED

6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION

ON TOP AND BOTTOM OF PACKAGE

3531fb

InformationfurnishedbyLinearTechnologyCorporationisbelievedtobeaccurateandreliable.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

LTC3531/

LTC3531-3.3/LTC3531-3

U

TYPICAL APPLICATIO

Complete USB/Li-Ion Powered System

with 3.3V_OUTand Linear Charger

LTC4055

5V (NOM)

FROM USB

CABLE

V

: USB OR BATTERY

OUT

OTHER

DC/DC

IN1

OUT

L1

10μH

IN2

CHRG

ACPR

HPWR

SUSP

BAT

SUSPEND

USB POWER

VNTC

SW1

SW2

V

OUT

3.1V TO 5.25V

3.3V

V

OUT

TIMER

CLPROG

PROG

IN

160mA

+

–

LTC3531-3.3

Li-Ion

C1

22μF

C2

10μF

SHDN

GND

100k

GND

SHDN WALL NTC

100k

0.1μF

3531 TA05

C1, C2: TAIYO YUDEN JMK316BJ106ML

L1: MURATA LQH43CN100K03 (650mA 0.24Ω)

RELATED PARTS

PART NUMBER

DESCRIPTION

COMMENTS

V : 2.6V to 16V, V

LT1930/LT1930A

1A (I ), 1.2MHz/2.2MHz, High Efﬁciency Step-Up DC/DC Converter

= 34V,

SW

IN

OUT(MAX)

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

Q

SD

LTC3400/LTC3400B

LTC3401/LTC3402

LTC3405/LTC3405A

LTC3406/LTC3406B

LTC3421

600mA (I ), 1.2MHz Synchronous Step-Up DC/DC Converter

V : 0.85V to 5V, V

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

Q

= 5V,

SW

IN

OUT(MAX)

SD

1A/2A (I ), 3MHz Synchronous Step-Up DC/DC Converter

V : 0.5V to 5V, V

= 6V, I = 38μA,

SW

IN

OUT(MAX) Q

I

< 1μA, MS Package

SD

300mA (I ), 1.5MHz Synchronous Step-Down DC/DC Converter

V : 2.7V to 6V, V

= 0.8V, I = 20μA,

OUT

IN

OUT(MIN) Q

I

≤ 1μA, MS10 Package

SD

600mA (I ), 1.5MHz Synchronous Step-Down DC/DC Converter

V : 2.5V to 5.5V, V

= 0.6V, I = 20μA,

Q

OUT

IN

OUT(MIN)

OUT(MAX)

I

≤ 1μA, ThinSOT Package

SD

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

V : 0.5V to 4.5V, V

= 5.25V, I = 12μA,

Q

SW

IN

I

< 1μA, QFN Package

SD

LTC3422

1.5A (I ), 3MHz Synchronous Step-Up DC/DC Converter

V : 0.5V to 4.5V, V

IN

= 5.25V, I = 25μA,

Q

SW

I

< 1μA, 3mm × 3mm DFN Package

SD

LTC3426

LTC3428

LTC3429

2A (I ), 1.2MHz Step-Up DC/DC Converter in SOT-23

V : 1.6V to 5V, V

up to 5.5V

SW

IN

OUT

4A (I ), 1.2MHz Step-Up DC/DC Converter

V : 1.6V to 5V, V

IN

SW

600mA (I ), 500kHz Synchronous Step-Up DC/DC Converter

V : 0.5V to 4.4V, V

= 5V, I = 20μA,

Q

SW

IN

OUT(MIN)

I

< 1μA, QFN Package

SD

LTC3440

LTC3441

600mA (I ), 2MHz Synchronous Buck-Boost DC/DC Converter

V : 2.5V to 5.5V, V

= 5.5V, I = 25μA,

Q

OUT

IN

OUT(MIN)

I

< 1μA, MS, DFN Packages

SD

600mA (I ), 2MHz Synchronous Buck-Boost DC/DC Converter

V : 2.5V to 5.5V, V

= 5.5V, I = 25μA,

OUT

IN

OUT(MIN) Q

I

< 1μA, DFN Package

SD

LTC3442

LTC3443

2MHz Synchronous Buck-Boost with Auto-Burst

V : 2.4V to 5.5V, V

up to 5.25V

IN

OUT

1.2A (I ), 600kHz Synchronous Buck-Boost DC/DC Converter

V : 2.4V to 5.5V, V

= 5.25V, I = 28μA,

OUT

IN

OUT(MIN) Q

I

< 1μA, MS Package

SD

LTC3458

LTC3458L

LTC3459

1.4A, 1.5MHz Synchronous Step-Up DC/DC Converter

1.7A, 1.5MHz Synchronous Step-Up DC/DC Converter

10V Micropower Synchronous Step-Up DC/DC Converter

V : 1.5V to 6V, V

up to 7.5V

IN

OUT

V : 1.5V to 6V, V

IN

up to 6V

up to 10V

V : 1.5V to 5.5V, V

IN

OUT

LTC3525/LTC3525-3.3/

LTC3525-5

400mA (I ), Synchronous Step-Up DC/DC Converter

with Output Disconnect

V : 0.5V to 4.5V, I = 7μA, I < 1μA,

IN Q SD

2mm × 2mm SC70 Package

SW

3531fb

LT 0807 REV B • PRINTED IN USA

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

16

●

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


型号：	LTC3531ES6-3.3#TRPBF
厂家：	Linear
描述：	LTC3531 - 200mA Buck-Boost Synchronous DC/DC Converters; Package: SOT; Pins: 6; Temperature Range: -40°C to 85°C 转换器稳压器开关式稳压器或控制器电源电路开关式控制器光电二极管
文件：	总16页 (文件大小：694K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LTC3531ES6-3.3#TRPBF [Linear]

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