LTC4066_技术文档

LTC4066/LTC4066-1

USB Power Controller and

Li-Ion Linear Charger with

Low Loss Ideal Diode

DESCRIPTION

The LTC^®4066/LTC4066-1 are USB power managers and

Li-Ion battery chargers designed to work in portable

battery-powered applications. The parts control the total

current used by the USB peripheral for operation and

battery charging. The total input current can be limited

to 100mA, 500mA or “unlimited” (i.e., above 2A). Battery

charge current is automatically reduced such that the sum

of the load current and the charge current does not exceed

the programmed input current limit.

FEATURES

n

Seamless Transition Between Input Power Sources:

Li-Ion Battery, USB and 5V Wall Adapter

n

Low Loss (50mΩ) Ideal Diode Path from BAT to OUT

n

Programmable Charge Current Detection (CHRG)

Load Dependent Charging Guarantees USB Input

n

Current Compliance

Analog Gas Gauge Function

n

Charges Single Cell Li-Ion Batteries Directly from

USB Port

n

Constant-Current/Constant-Voltage Operation with

The LTC4066/LTC4066-1 include a standalone constant-

current/constant-voltage linear charger for single cell

Li-ion batteries. The ﬂoat voltage applied to the battery

is held to a tight 0.8% tolerance, and charge current

is programmable using an external resistor to ground.

A programmable end-of-charge status output (CHRG)

indicates full charge. BAT pin charge and discharge cur-

Thermal Feedback to Maximize Charging Rate

Without Risk of Overheating*

n

Selectable 100% or 20% Current Limit

(e.g., 500mA/100mA)

n

Termination Timer Adapts to Actual Charge Current

n

Preset 4.2V Charge Voltage with 0.8% Accuracy

(4.1V for LTC4066-1)

rents can be monitored via an analog output (I

). Total

STAT

n

NTC Thermistor Input for Temperature Qualiﬁed

charge time is programmable by an external capacitor to

ground. When the battery drops 100mV below the ﬂoat

voltage, automatic recharging of the battery occurs. Also

featured is an NTC thermistor input used to monitor bat-

tery temperature while charging.

Charging

n

Thin Proﬁle (0.75mm) 24-Lead 4mm × 4mm

QFN Package

n

Ultrathin Proﬁle (0.55mm) 24-Lead 4mm × 4mm

UTQFN Package (LTC4066 Only)

The LTC4066/LTC4066-1 are available in a 24-pin thin

proﬁle(0.75mm)4mm×4mmQFNpackage.TheLTC4066

is also available in a 24-pin ultrathin proﬁle (0.55mm)

4mm × 4mm UTQFN package.

APPLICATIONS

n

Portable USB Devices

GPS, Cameras, Broadband Wireless Modems

n

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

is a trademark of Linear Technology Corporation. All other trademarks are the property of their

respective owners. *Protected by U.S. Patents including 6522118.

n

Mulitple Input Chargers

600

TYPICAL APPLICATION

I

IN

500

400

300

200

100

0

5V (NOM)

TO LDOs,

FROM USB

IN

OUT

BAT

REGs, ETC

CABLE V

BUS

V

4.7μF

NTC

510Ω

+

I

LOAD

NTC

WALL

SHDN

LTC4066

CHRG

ACPR

POL

I

BAT

CHARGING

SUSP

HPWR

CLDIS

SUSPEND USB POWER

500mA/100mA SELECT

TO ADC FOR

GAS GAUGE

I

INPUT CURRENT

LIMIT DISABLE

STAT

TIMER PROG CLPROG

GND

–100

0

100

200

300

(mA)

400

500

600

BAT

0.1μF

100k 2k

2k

I

LOAD

4066 TA01

(IDEAL DIODE)

4066 TA02

4066fc

1

LTC4066/LTC4066-1

ABSOLUTE MAXIMUM RATINGS ^{(Notes 1 to 6)}

Terminal Voltage

Pin Current (DC)

t < 1ms and Duty Cycle < 1%

IN (Note 7).......................................................... 2.7A

OUT, BAT (Note 7).................................................. 5A

Operating Temperature Range................. –40°C to 85°C

Maximum Operating Junction Temperature ......... 125°C

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

IN, OUT................................................... –0.3V to 7V

Steady State

IN, OUT, BAT ........................................... –0.3V to 6V

NTC, V , TIMER, PROG,

NTC

CLPROG, I

....................... –0.3V to (V + 0.3V)

STAT

CC

CHRG, HPWR, SUSP, SHDN,

WALL, ACPR, POL, CLDIS...................... –0.3V to 6V

PIN CONFIGURATION

TOP VIEW

24 23 22 21 20 19

OUT

BAT

OUT

BAT

NC

1

2

3

4

5

6

18 CHRG

OUT

BAT

OUT

BAT

NC

1

2

3

4

5

6

18 CHRG

ACPR

17

16

15

14

17

16

15

14

GND

25

V

NTC

13 HPWR

7

8

9

10 11 12

7

8

9 10 11 12

UF PACKAGE

24-LEAD (4mm s 4mm) PLASTIC QFN

PF PACKAGE

24-LEAD (4mm s 4mm) PLASTIC UTQFN

T

= 125°C, θ = 37°C/W

T

= 125°C, θ = 37°C/W

JMAX JA

JMAX

JA

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

ORDER INFORMATION

LEAD FREE FINISH

LTC4066EUF#PBF

LTC4066EUF-1#PBF

LTC4066EPF#PBF

TAPE AND REEL

PART MARKING

4066

PACKAGE DESCRIPTION

TEMPERATURE RANGE

LTC4066EUF#TRPBF

LTC4066EUF-1#TRPBF

LTC4066EPF#TRPBF

–40°C to 85°C

24-Lead (4mm × 4mm) Plastic QFN

24-Lead (4mm × 4mm) Plastic UTQFN

40661

4066T

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

Consult LTC Marketing for information on non-standard lead based ﬁnish parts.

For more information on lead free part marking, go to: http://www.linear.com/leadfree/

For more information on tape and reel speciﬁcations, go to: http://www.linear.com/tapeandreel/

4066fc

2

LTC4066/LTC4066-1

ELECTRICAL CHARACTERISTICS ^Thel denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T_A= 25°C. V_IN= 5V, V_BAT= 3.7V, HPWR = 5V, WALL = 0V, R_PROG= 100k,

R_CLPROG= R_ISTAT= 2k, unless otherwise noted.

SYMBOL PARAMETER

CONDITIONS

IN and OUT

BAT

MIN

TYP

MAX

5.5

UNITS

l

V

Input Supply Voltage

Input Voltage

4.35

V

IN

4.3

BAT

l

I

Input Supply Current

I

= I = 0 (Note 8)

ISTAT

0.5

50

10

1.2

100

20

mA

μA

IN

BAT

Suspend Mode; SUSP = 2V

Suspend Mode; SUSP = 2V, Wall = 2V, V

Shutdown; SHDN = 2V

= 4.8V

OUT

l

I

Output Supply Current

Battery Drain Current

V

= 5V, V = 0V, V = 4.3V, TIMER = 0V

400

800

μA

OUT

IN

BAT

l

BAT

= 4.3V, Charging Stopped

15

2.5

55

27

5

μA

BAT

Suspend Mode; SUSP = 2V

Shutdown; SHDN = 2V

V

IN

= 0V, BAT Powers OUT, No Load

100

I

Maximum Input Current Limit

(Note 9)

1.9

2.6

A

IN(MAX)

l

V

UVLO

Input or Output Undervoltage Lockout

V

Powers Part, Rising Threshold

OUT

3.6

3.8

4

V

IN

Powers Part, Rising Threshold

Input or Output Undervoltage Lockout

V

Rising – V Falling or

125

mV

ΔV

UVLO

IN

Rising – V

Falling

OUT

Current Limit

l

I

R

= 2k, HPWR = 5V

= 2k, HPWR = 0V

475

90

500

100

525

110

mA

LIM

CLPROG

R

ON

ON Resistance V to V

HPWR = 5V, 400mA Load

HPWR = 0V, 80mA Load

0.16

Ω

IN

OUT

l

V

CLPROG Pin Voltage

R

= 2k

= 1k

0.980 1.000

1.020

V

CLPROG

I

Soft-Start Inrush Current

IN or OUT

10

mA/μs

SS

V

ALEN

Automatic Current Limit Enable Threshold

Voltage

(V – V ) V Rising

25

–85

50

–60

75

–25

mV

IN

OUT IN

(V – V ) V Falling

IN

OUT IN

Battery Charger

V

FLOAT

Regulated Output Voltage

(0°C to 85°C), I = 2mA

BAT

4.165 4.200

4.158 4.200

4.235

4.242

V

BAT

l

I

= 2mA

(0°C to 85°C), I = 2mA (LTC4066-1)

4.066 4.100

4.059 4.100

4.134

4.141

V

BAT

I

= 2mA (LTC4066-1)

BAT

l

I

Current Mode Charge Current

R

= 100k, No Load

= 50k, No Load

460

920

500

540

mA

BAT

PROG

1000

1080

Maximum Charge Current

PROG Pin Voltage

(Note 9)

1.5

A

BAT(MAX)

l

V

R

PROG

R

PROG

= 100k

= 50k

0.980 1.000

1.020

V

PROG

l

k

Ratio of I (Charging) to I

I

= 50mA

875

900

925

950

1000

1125

1100

1075

1050

mA/mA

ISTAT

BAT

STAT

BAT

Pin Current

= 100mA

= 500mA

= 1000mA

l

V

End-of-Charge I

Pin Voltage

V

= V (4.2V, 4.1V for LTC4066-1)

FLOAT

94

35

100

50

106

60

3

mV

mA

V

EOC

STAT

BAT

I

Trickle Charge Current

= 2V, R

= 100k

PROG

TRIKL

l

V

TRIKL

Trickle Charge Threshold Voltage

Charger Enable Threshold Voltage

2.8

2.9

V

CEN

(V

– V ) High to Low, V = 4V

60

90

mV

OUT

BAT

– V ) Low to High, V = 4V

BAT

l

V

Recharge Battery Threshold Voltage

TIMER Accuracy

V

– V

RECHRG

60

100

130

10

mV

%

RECHRG

TIMER

FLOAT

t

= 4.2V (4.1V for LTC4066-1)

–10

BAT

Recharge Time

Percent of Total Charge Time

Percent of Total Charge Time, V < 2.8V

50

25

%

Low-Battery Trickle Charge Time

%

BAT

4066fc

3

LTC4066/LTC4066-1

ELECTRICAL CHARACTERISTICS ^Thel denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T_A= 25°C. V_IN= 5V, V_BAT= 3.7V, HPWR = 5V, WALL = 0V, R_PROG= 100k,

R_CLPROG= R_ISTAT= 2k, unless otherwise noted.

SYMBOL PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

T

Junction Temperature in Constant

Temperature Mode

105

°C

LIM

Ideal Diode

R

Incremental Resistance, V Regulation

I

= 500mA

= 3A

27

45

mΩ

FWD

ON

BAT

On-Resistance V to V

OUT

DIO(ON)

FWD

BAT

l

V

Voltage Forward Drop (V – V

)

I

= 5mA

= 200mA

= 2A

10

30

47

95

50

mV

BAT

OUT

BAT

k

Ratio of I (Discharging Through Ideal

I

= 5mA

= 20mA

850

1000

1150

mA/mA

DIO,ISTAT

BAT

Diode) to I

Pin Current

STAT

V

Diode Disable Battery Voltage

2.8

2.5

5.2

V

A

OFF

I

Load Current Limit for V Regulation

V

= 3.5V

FWD

ON

BAT

Diode Current Limit

3.8

1.2

D(MAX)

Logic

l

V

Output Low Voltage (CHRG, ACPR, POL)

Enable Input High Voltage

I

= 5mA

0.1

0.25

0.4

V

OL

SINK

SUSP, SHDN, HPWR, CLDIS Pin

SUSP, SHDN, HPWR, CLDIS

IH

Enable Input Low Voltage

V

IL

I

Logic Input Pull-Down Current

2

4

μA

V

PULLDN

l

V

Charger Shutdown Threshold Voltage on

TIMER

0.15

2

0.4

CHG,SD

I

Charger Shutdown Pull-Up Current on

TIMER

V

TIMER

= 0V

μA

CHG,SD

V

WALL

Wall Input Threshold Voltage

Wall Input Hysteresis

V

WALL

Rising Threshold

1.200 1.225

1.250

50

V

mV

nA

V

WALL

Rising – V

Falling Threshold

WALL

35

0

WALL,HYS

I

Wall Input Leakage Current

V

WALL

= 1V

WALL

NTC

I

V

Pin Current

Bias Voltage

V

= 2.5V

= 500μA

= 1V

1.5

4.4

2.5

4.85

0

3.5

1

mA

V

VNTC

NTC

VNTC

l

V

I

VNTC

I

NTC Input Leakage Current

V

μA

NTC

V

Cold Temperature Fault Threshold Voltage

Rising Threshold

Hysteresis

0.74 • V

0.02 • V

V

COLD

HOT

DIS

VNTC

Hot Temperature Fault Threshold Voltage

NTC Disable Voltage

Falling Threshold

Hysteresis

0.29 • V

0.01 • V

V

VNTC

l

NTC Input Voltage to GND (Falling)

Hysteresis

75

100

35

125

mV

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.

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

Continuous operation above the speciﬁed maximum operating junction

temperature may impair device reliability.

Note 6: The LTC4066/LTC4066-1 are 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.

Note 2: V is the greater of V , V

or V

.

BAT

CC

IN OUT

Note 3: Pins 1, 3 and 8 (OUT) should be tied together with a low

impedance to ensure that the difference between the three pins does not

exceed 50mV. Pins 2, 4 and 5 (BAT) should be tied together with a low

impedance to ensure that the difference between the three pins does not

exceed 50mV.

Note 4: All voltage values are with respect to GND.

Note 5: This IC includes overtemperature protection that is intended

Note 7: Guaranteed by long term current density limitations.

Note 8: Total input current is equal to this speciﬁcation plus 1.003 × I

BAT

where I is the charge current.

BAT

Note 9: Accuracy of programmed current may degrade for currents greater

than 1.5A.

to protect the device during momentary overload conditions. Junction

4066fc

4

LTC4066/LTC4066-1

TYPICAL PERFORMANCE CHARACTERISTICS

Battery Drain Current vs

Input Supply Current

vs Temperature

Input Supply Current vs

Temperature (BAT Powers OUT,

Temperature (Suspend Mode)

No Load)

70

60

50

40

30

20

10

0

900

800

700

600

500

400

300

200

100

V

R

= 5V

V

= 0V

IN

= 4.2V

BAT

V

R

= 5V

IN

= 4.2V

BAT

PROG

BAT

PROG

60

50

40

30

20

10

0

= 100k

= 2k

CLPROG

SUSP = 5V

0

50

TEMPERATURE (°C)

100

–50 –25

0

25

75

–50

0

25

50

75

100

–25

–50

–25

0

25

100

50

75

TEMPERATURE (°C)

4066 G03

4066 G02

4066 G01

Input Current Limit vs

Temperature, HPWP = 5V

Input Current Limit vs

Temperature, HPWR = 0V

CLPROG Pin Voltage vs

Temperature

1200

1000

800

600

400

200

0

525

515

505

495

110

108

106

104

102

100

98

V

= 5V

CLPROG

V

R

= 5V

V

R

= 5V

IN

R

IN

= 2k

= 3.7V

BAT

PROG

BAT

PROG

= 100k

HPWR = 5V

= 2k

CLPROG

96

HPWR = 0V

25

94

485

475

92

90

–50

0

50

75

100

–25

–50

0

25

50

75

100

–25

25

50

75

100

–25

0

TEMPERATURE (°C)

4066 G06

4066 G04

4066 G05

Battery Regulation (Float)

Voltage vs Temperature

PROG Pin Voltage vs Temperatrue

V_FLOATLoad Regulation

4.220

4.200

4.180

4.160

4.140

4.120

4.100

4.080

4.300

4.250

4.200

4.150

4.100

4.050

4.000

1.020

1.015

1.010

1.005

R

T

= 34k

V

= 5V

PROG

V

IN

= 5V

PROG

A

IN

= 25°C

R

= 100k

LTC4066

1.000

0.995

LTC4066-1

0.990

0.985

0.980

LTC4066-1

50

–25

0

50

0

250

500

750 1000 1250 1500

(mA)

–25

0

–50

75

100

–50

75

100

25

I

TEMPERATURE (°C)

BAT

4066 G08

4066 G07

4066 G09

4066fc

5

LTC4066/LTC4066-1

TYPICAL PERFORMANCE CHARACTERISTICS

Regulated Output Voltage–

Recharge Threshold Voltage

vs Temperature

Battery Current and Voltage

vs Time (LTC4066)

Input R_ONvs Temperature

225

200

175

150

125

100

75

600

500

6

5

120

115

110

105

V

IN

= 5V

I

= 400mA

LOAD

V

= 4.5V

IN

V

IN

= 5V

400

300

4

3

V

IN

= 5.5V

100

95

200

100

0

2

1

0

400mAhr CELL

90

85

80

V

T

= 5V

IN

A

= 25°C

R

= 105k

PROG

–25

0

50

–50

–25

0

25

50

75

100

0

50

100

150

–50

75

100

25

TEMPERATURE (°C)

TIME (MINUTES)

TEMPERATURE (°C)

4066 G11

4066 G12

4066 G10

Charging from USB, I_BATvs V_BAT

(LTC4066)

Charging from USB, Low Power,

I_BATvs V_BAT(LTC4066)

Undervoltage Current Limit

I_BATvs V_OUT

600

500

120

100

1500

1250

V

R

= 5V

V

R

= 5V

T

= 25°C

IN

OUT

IN

OUT

A

= NO LOAD

= 100k

= NO LOAD

= 100k

WALL = 2V

= 3.5V

V

PROG

BAT

= 2k

CLPROG

HPWR = 5V

= 25°C

HPWR = 0V

400

80

1000

750

T

A

T

= 25°C

A

R

= 34k

PROG

300

200

60

40

R

= 50k

PROG

500

250

0

100

0

20

0

R

= 100k

4.40

PROG

0

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

(V)

0

0.5 1.0 1.5 2.0 2.5 3.0 4.0 4.5

3.5

4.00

4.10

4.20

V

4.30

(V)

4.50

V

BAT

(V)

BAT

OUT

4066 G13

4066 G14

4066 G15

Charge Current vs Temperature

(Thermal Regulation)

Ideal Diode Current vs Forward

Voltage and Temperature

Ideal Diode Resistance and

Current vs Forward Voltage

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

1000

750

500

250

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

225

200

175

150

125

100

75

R

= 50k

= 100k

25

V

= 3.7V

V

T

= 3.5V

PROG

BAT

IN

BAT

= 0V

IN

= 25°C

25°C

0°C

–50°C

A

125°C

75°C

R

PROG

R

DIO(ON)

50

V

JA

= 5V

BAT

IN

R

FWD

= 3.5V

= 43°C/W

25

Q

0

200

–50 –25

0

50

75 100 125

0

20 40 60 80 100 120 140 160 180 200

(mV)

0

20 40 60 80 100

120 140 160 180

TEMPERATURE (°C)

V

FWD

(mV)

FWD

4066 G16

4066 G17

4066 G18

4066fc

6

LTC4066/LTC4066-1

TYPICAL PERFORMANCE CHARACTERISTICS

I_STATPin Current vs

Battery Current

I_STATPin Current vs Battery

Current (Low Currents)

1500

1250

1000

750

500

250

0

10

IDEAL DIODE

CHARGING

IDEAL DIODE

CHARGING

8

6

4

2

0

V

T

= 4.2V

= 34k

BAT

V

T

= 4.2V

= 5V

BAT

IN

A

IN

A

= 5V

= 25°C

R

PROG

–1500

–500

0

500

1000 1500

–10 –8 –6 –4 –2

I

0

2

4

6

8

10

–1000

I

(mA)

BAT

4006 G19

4066 G20

Input Connect Waveforms

Input Disconnect Waveforms

Response to HPWR

V

IN

HPWR

5V/DIV

V

IN

5V/DIV

V

OUT

5V/DIV

I

IN

I

IN

0.5A/DIV

I

BAT

0.5A/DIV

4066 G22

4066 G23

4066 G21

V

I

= 3.85V

= 100mA

1ms/DIV

V

I

= 3.85V

= 50mA

1ms/DIV

V

I

= 3.85V

= 100mA

1ms/DIV

BAT

OUT

BAT

OUT

BAT

OUT

WALL Connect Waveforms,

V_IN= 0V

WALL Disconnect Waveforms,

V_IN= 0V

Respond to Suspend

WALL

5V/DIV

SUSPEND

5V/DIV

WALL

5V/DIV

V

OUT

5V/DIV

I

IN

WALL

0.5A/DIV

I

BAT

0.5A/DIV

4066 G24

4066 G26

4066 G25

V

I

= 3.85V

= 100mA

= 71.5k

1ms/DIV

V

I

= 3.85V

= 50mA

1ms/DIV

V

I

= 3.85V

= 100mA

= 71.5k

1ms/DIV

BAT

OUT

BAT

OUT

R

PROG

4066fc

7

LTC4066/LTC4066-1

TYPICAL PERFORMANCE CHARACTERISTICS

WALL Connect Waveforms,

V_IN= 5V

WALL Disconnect Waveforms,

V_IN= 5V

WALL

5V/DIV

I

IN

0.5A/DIV

I

WALL

0.5A/DIV

I

BAT

I

BAT

0.5A/DIV

4066 G28

4066 G27

V

I

= 3.85V

= 100mA

= 71.5k

1ms/DIV

V

I

= 3.85V

= 100mA

= 71.5k

1ms/DIV

BAT

OUT

R

PROG

PIN FUNCTIONS

OUT (Pins 1, 3, 8): Voltage Output. This pin is used to

BAT pin) supplied through the input is set to the current

programmed by the PROG pin but will be limited by the

input current limit if charge current is set greater than the

input current limit.

provide controlled power to a USB device from either

USB V

(IN) or the battery (BAT) when the USB is not

BUS

present. This pin can also be used as an input for battery

charging when the USB is not present and a wall adapter

isappliedtothispin. OUTshouldbebypassedwithatleast

4.7μF to GND. Connect Pins 1, 3 and 8 with a resistance

no greater than 10mΩ.

CLDIS (Pin 10): Current Limit Disable. This logic input

is used to disable the input current limit programmed by

CLPROG. A voltage greater than 1.2V on the pin will set

the current limit to I

(typically 2.6A). A weak pull-

IN(MAX)

BAT (Pins 2, 4, 5): Connect to a single cell Li-Ion battery.

Thispinisusedasanoutputwhenchargingthebattery,and

as an input when supplying power to OUT. When the OUT

pin potential drops below the BAT pin potential, an ideal

down current is internally applied to this pin to ensure

it is low at power-up when the input is not being driven

externally.

SUSP (Pin 11): Suspend Mode Input. Pulling this pin

above 1.2V will disable the power path from IN to OUT. The

supply current from IN will be reduced to comply with the

USB speciﬁcation for Suspend mode. Both the ability to

charge the battery from OUT and the ideal diode function

(from BAT to OUT) will remain active. Suspend mode will

diodefunctionconnectsBATtoOUTandpreventsV from

OUT

droppingmorethan50mVbelowV .Aprecisioninternal

BAT

resistor divider sets the ﬁnal ﬂoat (charging) potential on

thispin. Theinternalresistordividerisdisconnectedwhen

IN and OUT are in undervoltage lockout. Connect Pins 2,

4 and 5 with a resistance no greater than 10mΩ.

reset the charge timer if V

is less than V

while in

OUT

BAT

IN (Pin 9): Input Supply. Connect to USB supply, V

.

suspend mode. If V

is kept greater than V , such as

BUS

OUT

Inputcurrenttothispinislimitedtoeither20%or100%of

thecurrentprogrammedbytheCLPROGpinasdetermined

by the state of the HPWR pin. The input current limit can

also be disabled by pulling CLDIS high. Charge current (to

when a wall adapter is present, the charge timer will not be

reset when the part is put in suspend. A weak pull-down

current is internally applied to this pin to ensure it is low

at power-up when the pin is not being driven externally.

4066fc

8

LTC4066/LTC4066-1

PIN FUNCTIONS

SHDN (Pin 12): Shutdown Input. Pulling this pin greater

than 1.2V will disable the entire part and place it in a low

supply current mode of operation. All power paths will be

disabled. A weak pull-down current is internally applied

to this pin to ensure it is enabled at power-up when the

pin is not being driven externally.

ACPR (Pin 17): Wall Adapter Present Output. Active low

open-drain output pin. A low on this pin indicates that the

wall adapter input comparator has had its input pulled

above the input threshold. This feature is disabled if the

part is shut down or if no power is present on IN or OUT

or BAT (i.e., below UVLO thresholds).

HPWR(Pin13):HighPowerSelect.Thislogicinputisused

to control the input current limit. A voltage greater than

1.2V on the pin will set the input current limit to 100% of

the current programmed by the CLPROG pin. A voltage

less than 0.4V on the pin will set the input current limit

to 20% of the current programmed by the CLPROG pin.

A weak pull-down current is internally applied to this pin

to ensure it is low at power-up when the pin is not being

driven externally.

CHRG (Pin 18): Open-Drain Charge Status Output. When

the battery is being charged, the CHRG pin is pulled low by

aninternalN-channelMOSFET. Whenthetimerrunsoutor

the charge current drops below a programmable current

level or the input supply or output supply is removed, the

CHRG pin is forced to a high impedance state.

POL (Pin 19): Battery Current Status Polarity Pin. This

open-drainoutputpinindicateswhetherthecurrentﬂowing

out of the I

pin represents one-thousandth of the cur-

STAT

NTC (Pin 14): Input to the NTC Thermistor Monitoring

Circuits. Under normal operation, tie a thermistor from

the NTC pin to ground and a resistor of equal value from

rent ﬂowing into or out of the BAT pins. The POL pin will

pull down when current is ﬂowing out of the BAT pin (i.e.,

charging) and will assume a high impedance state when

current is ﬂowing into the BAT pin (i.e., ideal diode).

NTC to V . When the voltage on this pin is above 0.74

NTC

• V

(Cold, 0°C) or below 0.29 • V

(Hot, 50°C)

VNTC

WALL (Pin 20): Wall Adapter Present Input. Pulling this

pin above 1.225V will disconnect the power path from IN

to OUT. The ACPR pin will also be pulled low to indicate

that a wall adapter has been detected.

the timer is suspended, but not cleared, the charging is

disabled and the CHRG pin remains in its former state.

When the voltage on NTC comes back between 0.74 •

V

and 0.29 • V

, the timer continues where it left

VNTC

TIMER (Pin 21): Timer Capacitor. Placing a capacitor,

off and charging is re-enabled if the battery voltage is

below the recharge threshold. There is approximately 3°C

oftemperaturehysteresisassociatedwitheachoftheinput

comparators. Connect the NTC pin to ground to disable

thisfeature.ThiswilldisablealloftheLTC4066/LTC4066-1

NTC functions.

C

, to GND sets the timer period. The timer period

TIMER

is:

C_TIMER•R_PROG• 3Hours

t_TIMER(Hours) =

0.1μF •100k

Charge time is increased if charge current is reduced due

to load current, thermal regulation and current limit selec-

tion (HPWR). Shorting the TIMER pin to GND disables the

battery charging functions.

V

(Pin15):OutputBiasVoltageforNTC.Aresistorfrom

NTC

this pin to the NTC pin will bias the NTC thermistor.

GND(Pin16),ExposedPad(Pin25):Ground.TheExposed

Pad is ground and must be soldered to the PC board for

maximum heat transfer. The Exposed Pad must be electri-

cally connected to the GND pin.

4066fc

9

LTC4066/LTC4066-1

PIN FUNCTIONS

CLPROG (Pin 22): Current Limit Program and Input Cur-

PROG (Pin 23): Charge Current Program. Connecting a

resistor, R , to ground programs the battery charge

rent Monitor. Connecting a resistor, R

, to ground

CLPROG

PROG

programs the input to output current limit. The current

limit is programmed as follows:

current. The battery charge current is programmed as

follows:

1000V

I_CL(A) =

50,000V

I_CHG(A) =

R_CLPROG

R_PROG

In USB applications the resistor R

to no less than 2.1k.

should be set

I

(Pin24):BatteryCurrentStatusPin.One-thousandth

CLPROG

STAT

of the current ﬂowing into or out of the BAT pins ﬂows

out of this pin. The POL polarity pin indicates which

direction current is ﬂowing. If the current ﬂowing into

The voltage on the CLPROG pin is always proportional to

the current ﬂowing through the IN to OUT power path.

This current can be calculated as follows:

the BAT pins drops below 1mA, then the I

continue to source 1μA. The I

charge current level at which the CHRG pin transitions to

its high impedance state. When the I voltage drops

pin will

STAT

pin also programs the

STAT

V_CLPROG

R_CLPROG

I_IN(A) =

•1000

STAT

below 0.1V while charging in constant voltage mode the

CHRG pin will transition to a high impedance state. This

corresponds to a BAT current of:

0.1V

R_ISTAT

I_BAT(A) =

•1000

4066fc

10

LTC4066/LTC4066-1

BLOCK DIAGRAM

V

BUS

9

1,3,8

OUT

2,4,5

BAT

IN

+

–

CLDIS

CURRENT LIMIT DISABLE

2μA

IDEAL

DIODE

25mV

10

CURRENT LIMIT

CHARGER

CC/CV REGULATOR

IN

OUT

I

CNTL

LIM

BAT

POL

ENABLE

19

–

+

SOFT-START

1V

+

–

I

IN

I

LIM

CP

1000

CURRENT CONTROL

DIE

CL

CLPROG

22

13

100k

TEMP 105°C

500mA/100mA

+

–

HPWR

IN OUT BAT

TA

2μA

SOFT-START2

CHRG

CHARGE CONTROL

+

–

+

–

1V

0.25V

CHG

PROG

WALL

+

–

2.9V

BATTERY

UVLO

23

20

BAT UV

100k

+

–

4.1V

RECHARGE

(4.0V

1.25V

+

–

ACPR

LTC4066-1)

VOLTAGE DETECT

UVLO

17

BAT UV

V

RECHRG

NTC

15

14

TIMER

OSCILLATOR

21

18

CONTROL LOGIC

–

+

100k

HOLD

CLK

CHRG

TOOCOLD

TOOHOT

STOP

NTCERR

RESET

NTC

COUNTER

NTC

100k

–

+

0.1V

+

–

|I

|

BAT

1000

EOC

+

–

NTC ENABLE

2μA

0.1V

I

STAT

GND

16

SHDN

SUSP

12

11

24

4066 BD

2k

4066fc

11

LTC4066/LTC4066-1

OPERATION

The LTC4066/LTC4066-1 are complete PowerPath^TM

controllers for battery-powered USB applications. The

LTC4066/LTC4066-1aredesignedtoreceivepowerfroma

USB source, a wall adapter or a battery. It can then deliver

power to an application connected to the OUT pin and a

batteryconnectedtotheBATpin(assumingthatanexternal

supply other than the battery is present). Power supplies

Furthermore,poweringswitchingregulatorloadsfromthe

OUT pin (rather than directly from the battery), results in

shorter battery charge times. This is due to the fact that

switchingregulatorstypicallyrequireconstantinputpower.

WhenthispowerisdrawnfromtheOUTpinvoltage(rather

than the lower BAT pin voltage) the current consumed

by the switching regulator is lower, leaving more current

available to charge the battery.

that have limited current resources (such as USB V

BUS

supplies) should be connected to the IN pin which has a

programmable current limit. Battery charge current will

be adjusted to ensure that the sum of the charge current

and load current does not exceed the programmed input

current limit.

The LTC4066/LTC4066-1 also have the ability to receive

power from a wall adapter. Wall adapter power can be con-

nectedtotheoutput(loadside)oftheLTC4066/LTC4066-1

through an external device such as a power Schottky or

FET, as shown in Figure 1. The LTC4066/LTC4066-1 have

the unique ability to use the output, which is powered

by the wall adapter, as a path to charge the battery while

providing power to the load. A wall adapter comparator

on the LTC4066/LTC4066-1 can be conﬁgured to detect

the presence of the wall adapter and shut off the connec-

tion to the USB to prevent reverse conduction out to the

USB bus.

An ideal diode function provides power from the battery

whenoutput/loadcurrentexceedstheinputcurrentlimitor

when input power is removed. Powering the load through

the ideal diode instead of connecting the load directly to

the battery allows a fully charged battery to remain fully

charged until external power is removed. Once external

power is removed, the output drops until the ideal diode

is forward biased. The forward biased ideal diode will then

provide the output power to the load from the battery.

PowerPath is a trademark of Linear Technology Corporation.

WALL

ADAPTER

CURRENT LIMIT

IN

OUT

USB V

CONTROL

9

BUS

1,3,8

ENABLE

LOAD

IDEAL

DIODE

CHRG

CONTROL

WALL

20

+

–

BAT

2,4,5

+

1.25V

Li-Ion

4066 F01

Figure 1. Simpliﬁed Block Diagram—PowerPath

4066fc

12

LTC4066/LTC4066-1

OPERATION

Table 1. Operating Modes—PowerPath States

Current Limited Input Power (IN to OUT)

WALL PRESENT SHUTDOWN

SUSPEND

V

> 3.8V

V

> (V

+ 100mV)

V

IN

> (V + 100mV)

CURRENT LIMIT ENABLED

IN

OUT

BAT

Y

X

N

X

Y

X

N

X

Y

X

N

X

N

X

Y

X

N

Y

N

Y

X

N

X

Y

Battery Charger (OUT to BAT)

WALL PRESENT SHUTDOWN

SUSPEND

V

> 4.35V

V

> (V + 100mV)

CHARGER ENABLED

OUT

BAT

X

Y

X

N

X

N

X

Y

X

N

Y

N

Y

Ideal Diode (BAT to OUT)

WALL PRESENT SHUTDOWN

SUSPEND

V

> 2.8V

V

> V

X

V

IN

DIODE ENABLED

BAT

OUT

X

Y

X

N

X

N

X

Y

X

N

Y

X

N

Y

Table 2. Operating Modes—Pin Currents vs Programmed Currents (Powered from IN)

PROGRAMMING OUTPUT CURRENT BATTERY CURRENT

INPUT CURRENT

I

CL

= I

I

< I

CL

I

= I

BAT

– I

I

= I + I

Q

CHG

OUT

CL

CHG

BAT

CHG

OUT

IN

CL

I

= I = I

I

= 0

= I + I

Q

OUT

I

> I

CL

I

= I – I

= I + I

Q

OUT

BAT

CL

OUT

I

CL

> I

I

< (I – I

)

I

= I

CL

I

= I + I

+ I

CHG

OUT

CL

CHG

BAT

CHG

OUT

IN

Q

CHG

OUT

> (I – I

I

= I – I

I

= I + I

Q

CL

BAT

IN

CL

I

= I

> I

I

= 0

CL

= I + I

Q

= I + I

Q

OUT

CL

BAT

= I – I

BAT

OUT

I

CL

< I

I

< I

CL

> I

CL

I

= I – I

CL

I

= I + I

Q

= I + I

Q

CHG

OUT

BAT

CL

OUT

IN

CL

= I – I

4066fc

13

LTC4066/LTC4066-1

OPERATION

4066fc

14

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

USB Current Limit and Charge Current Control

The LTC4066/LTC4066-1 reduce battery charge current

such that the sum of the battery charge current and the

loadcurrentdoesnotexceedtheprogrammedinputcurrent

limit(one-ﬁfthoftheprogrammedinputcurrentlimitwhen

HPWR is low, see Figure 2). The battery charge current

goes to zero when load current exceeds the programmed

input current limit (one-ﬁfth of the limit when HPWR is

low).Iftheloadcurrentisgreaterthanthecurrentlimit,the

output voltage will drop to just under the battery voltage

where the ideal diode circuit will take over and the excess

load current will be drawn from the battery.

The current limit and charger control circuits of the

LTC4066/LTC4066-1 are designed to limit input current as

wellascontrolbatterychargecurrentasafunctionofI

.

OUT

The programmed input current limit, I , is deﬁned as:

CL

⎛ 1000

⎝R_CLPROG

⎞

1000V

R_CLPROG

I =

CL

• V_CLPROG

=

⎜

⎟

⎠

The programmed battery charge current, I , is deﬁned

CHG

as:

⎛ 50,000

⎝ R_PROG

⎞

50,000V

R_PROG

Programming Current Limit

I_CHG

=

• V_PROG

=

⎜

⎟

⎠

The formula for input current limit is:

Input current, I , is equal to the sum of the BAT pin output

IN

⎛ 1000

⎝R_CLPROG

⎞

1000V

R_CLPROG

current and the OUT pin output current:

I =

• V_CLPROG

=

⎜

⎟

⎠

CL

I = I

+ I

BAT

IN

OUT

where V

is the CLPROG pin voltage and R

is

CLPROG

The current limiting circuitry in the LTC4066/LTC4066-1

can and should be conﬁgured to limit current to 500mA

for USB applications (selectable using the HPWR pin and

programmed using the CLPROG pin).

the total resistance from the CLPROG pin to ground.

For example, if typical 500mA current limit is required,

calculate:

1V

500mA

R_CLPROG

=

•1000 = 2k

600

500

400

300

200

100

0

120

100

80

600

500

400

300

200

100

0

I

IN

I

IN

I

IN

I

LOAD

60

I

= I

BAT CHG

40

I

BAT

I

= I – I

BAT CL OUT

I

CHARGING

BAT

20

CHARGING

0

–100

–20

–100

0

100

200

300

(mA)

400

500

600

0

20

40

60

(mA)

80

100

120

0

100

200

300

(mA)

400

500

600

I

BAT

I

LOAD

(IDEAL DIODE)

4066 F02a

4055 F02c

(2a) High Power Mode/Full Charge

R_PROG= 100k and R_CLPROG= 2k

(2b) Low Power Mode/Full Charge

R_PROG= 100k and R_CLPROG= 2k

(2c) High Power Mode with

I_CL= 500mA and I_CHG= 250mA

R_PROG= 200k and R_CLPROG= 2k

Figure 2. Input and Battery Currents as a Function of Load Current

4066fc

15

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

In USB applications, the minimum value for R_CLPROG

should be 2.1k. This will prevent the application current

from exceeding 500mA due to LTC4066/LTC4066-1 toler-

ancesandquiescentcurrents.A2.1kCLPROGresistorwill

give a typical current limit of 476mA in high power mode

(HPWR = 1) or 95mA in low power mode (HPWR = 0).

ideal diode circuit (along with the recommended 4.7μF

capacitor on the OUT pin) allows the LTC4066/LTC4066-1

to handle large transient loads and wall adapter or USB

V

connect/disconnect scenarios without the need for

BUS

large bulk capacitors. The ideal diode responds within a

few microseconds and prevents the OUT pin voltage from

dipping below the BAT pin voltage by more than 50mV.

V

will typically servo to 1V; however, if I

+ I

OUT BAT

CLPROG

< I then V

will track the input current according

Forward regulation for the ideal diode from BAT to OUT

has three operational ranges, depending on the magni-

tude of the diode load current. For small load currents,

the LTC4066/LTC4066-1 will provide a constant voltage

drop; this operating mode is referred to as “constant

CL

CLPROG

to the following equation:

V_CLPROG

R_CLPROG

I =

IN

•1000

V ” regulation. As the current exceeds I

the voltage

ON

FWD

For best stability over temperature and time, 1% metal

ﬁlm resistors are recommended.

drop will increase linearly with the current with a slope of

1/R ;thisoperatingmodeisreferredtoas“constant

DIO(ON)

R ”regulation.Asthecurrentincreasesfurther,exceeding

Ideal Diode from BAT to OUT

ON

MAX

I

, the forward voltage drop will increase rapidly; this

If a battery is the only power supply available or if the load

current exceeds the programmed input current limit, then

the battery will automatically deliver power to the load via

an ideal diode circuit between the BAT and OUT pins. The

operatingmodeisreferredtoas“constantI ”regulation.

The characteristics for parameters R , R , V

FWD

ON

and

FWD ON FWD

are speciﬁed with the aid of Figure 3.

I

CONSTANT

ON

LTC4066

I

MAX

CONSTANT

ON

SLOPE: 1/R

DIO(ON)

R

I

FWD

SCHOTTKY

DIODE

CONSTANT

ON

SLOPE: 1/R

FWD

V

4066 F03

0

FORWARD VOLTAGE (V)

V

FWD

Figure 3. LTC4066/LTC4066-1 vs Schottky Diode Forward Voltage Drop

4066fc

16

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

Battery Charger

the voltage on the BAT pin rises above 2.8V. In constant-

current mode, the charge current is set by R

. When

PROG

The battery charger circuits of the LTC4066/LTC4066-1

are designed for charging single cell lithium-ion batter-

ies. Featuring an internal P-channel power MOSFET, the

charger uses a constant-current/constant-voltage charge

algorithm with programmable current and a program-

mabletimerforchargetermination. Chargecurrentcanbe

programmed up to 1.5A. The ﬁnal ﬂoat voltage accuracy

is 0.8% typical. No blocking diode or sense resistor is

required when powering the IN pin. The CHRG open-drain

statusoutputprovidesinformationregardingthecharging

status of the LTC4066/LTC4066-1 at all times. An NTC

input provides the option of charge qualiﬁcation using

battery temperature.

the battery approaches the ﬁnal ﬂoat voltage, the charge

current begins to decrease as the LTC4066/LTC4066-1

switches to constant-voltage mode. When the charge

current drops below a level programmed by the I

STAT

while in constant-voltage mode the CHRG pin assumes a

high impedance state.

An external capacitor on the TIMER pin sets the total

minimum charge time. When this time elapses the

charge cycle terminates and the CHRG pin assumes a

high impedance state, if it has not already done so. While

charging in constant-current mode, if the charge current

is decreased by thermal regulation or in order to maintain

the programmed input current limit the charge time is

automatically increased. In other words, the charge time

is extended inversely proportional to charge current de-

livered to the battery. For Li-Ion and similar batteries that

require accurate ﬁnal ﬂoat potential, the internal bandgap

reference,voltageampliﬁerandtheresistordividerprovide

regulation with 0.8% accuracy.

An internal thermal limit reduces the programmed charge

current if the die temperature attempts to rise above a

presetvalueofapproximately105°C. Thisfeatureprotects

the LTC4066/LTC4066-1 from excessive temperature, and

allows the user to push the limits of the power handling

capability of a given circuit board without risk of dam-

aging the LTC4066/LTC4066-1. Another beneﬁt of the

LTC4066/LTC4066-1 thermal limit is that charge current

can be set according to typical, not worst-case, ambient

temperatures for a given application with the assurance

that the charger will automatically reduce the current in

worst-case conditions.

Trickle Charge and Defective Battery Detection

At the beginning of a charge cycle, if the battery voltage

is low (below 2.8V) the charger goes into trickle charge

reducingthechargecurrentto10%ofthefull-scalecurrent.

If the low-battery voltage persists for one quarter of the

total charge time, the battery is assumed to be defective,

the charge cycle is terminated and the CHRG pin output

assumes a high impedance state. If for any reason the

battery voltage rises above ~2.8V, the charge cycle will

be restarted. To restart the charge cycle (i.e., when the

deadbatteryisreplacedwithadischargedbattery), simply

remove the input voltage and reapply it, cycle the TIMER

pin to 0V or cycle the SHDN pin to 0V.

The charge cycle begins when the voltage at the OUT pin

rises above the output UVLO level and the battery voltage

isbelowtherechargethreshold.Nochargecurrentactually

ﬂowsuntiltheOUTvoltageisgreaterthantheoutputUVLO

level and 100mV above the BAT voltage. At the beginning

of the charge cycle, if the battery voltage is below 2.8V,

the charger goes into trickle charge mode to bring the

cell voltage up to a safe level for charging. The charger

goes into the fast charge constant-current mode once

4066fc

17

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

Programming Charge Current

The formula for the battery charge current is:

V

where V

is the I

pin voltage and R

STAT

is the total

ISTAT

STAT

ISTAT

resistance from the I

pin to ground. These pins enable

a true gas gauge function to be performed on the battery

with an external ADC and integrator. See Gas Gauge for

more information.

I_CHG= I

• 50,000 = ^PROG• 50,000

(

)

PROG

R_PROG

where V

is the PROG pin voltage and R

is the

The Charge Timer

PROG

total resistance from the PROG pin to ground. Keep in

mind that when the LTC4066/LTC4066-1 are powered

from the IN pin, the programmed input current limit takes

precedence over the charge current. In such a scenario,

the charge current cannot exceed the programmed input

current limit.

The programmable charge timer is used to terminate the

charge cycle. The timer duration is programmed by an

external capacitor at the TIMER pin. The charge time is

typically:

C_TIMER•R_PROG• 3Hours

t_TIMER(Hours) =

0.1μF •100k

For example, if typical 500mA charge current is required,

calculate:

The timer starts when an input voltage greater than the

undervoltage lockout threshold level is applied or when

leavingshutdownandthevoltageonthebatteryislessthan

the recharge threshold. At power-up or exiting shutdown

with the battery voltage less than the recharge threshold,

the charge time is a full cycle. If the battery is greater than

therechargethreshold,thetimerwillnotstartandcharging

is prevented. If after power-up the battery voltage drops

below the recharge threshold, or if after a charge cycle

the battery voltage is still below the recharge threshold,

the charge time is set to one-half of a full cycle.

1V

500mA

⎛

⎜

⎝

⎞

⎟

⎠

R_PROG

=

• 50,000 = 100k

For best stability over temperature and time, 1% metal

ﬁlm resistors are recommended. Under trickle charge

conditions, this current is reduced to 10% of the full-

scale value.

Monitoring Charge Current

The I

and POL pins provide a means for monitoring

STAT

the BAT pin current. The I

pin sources a current equal

STAT

TheLTC4066/LTC4066-1haveafeaturethatextendscharge

time automatically. Charge time is extended if the charge

current in constant-current mode is reduced due to load

current or thermal regulation. This change in charge time

is inversely proportional to the change in charge current.

As the LTC4066/LTC4066-1 approach constant-voltage

mode the charge current begins to drop. This change in

charge current is due to normal charging operation and

does not affect the timer duration.

to one-thousandth of the absolute value of the current

ﬂowing in the BAT pin. The POL pin indicates the polarity

of the BAT pin current. When current is ﬂowing from OUT

to BAT (i.e., charging), the POL pin pulls to ground. When

current is ﬂowing from BAT to OUT (ideal diode), the POL

pin assumes a high impedance. If a resistor, R

, is

ISTAT

placed from the I

BAT current is:

pin to ground, then the formula for

STAT

V

ISTAT

I_BAT

=

•1000

R_ISTAT

4066fc

18

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

Consider, for example, a USB charge condition where

The current level at which the CHRG pin changes state is

R

= 2k, R

= 100k and C

= 0.1μF. This

programmed by the I

pin. As described in Monitoring

CLPROG

PROG

TIMER

STAT

corresponds to a three hour charge cycle. However, if the

HPWR input is set to a logic low, then the input current

limit will be reduced from 500mA to 100mA. With no ad-

ditional system load, this means the charge current will

be reduced to 100mA. Therefore, the termination timer

will automatically slow down by a factor of ﬁve until the

Charge Current and Gas Gauge, the I

pin sources a

STAT

current proportional to the BAT pin current. The LTC4066/

LTC4066-1 monitor the voltage on the I pin and turns

STAT

off the CHRG N-channel pull-down when V

drops

ISTAT

below 100mV while in constant-voltage mode. The CHRG

current detection threshold can be calculated by the fol-

lowing equation:

charger reaches constant voltage mode (i.e., V = 4.2V,

BAT

4.1V for LTC4066-1) or HPWR is returned to a logic high.

Thechargecycleisautomaticallylengthenedtoaccountfor

the reduced charge current. The exact time of the charge

cycle will depend on how long the charger remains in

constant current mode and/or how long the HPWR pin

remains a logic low.

0.1V

R_ISTAT

100V

R_ISTAT

I_DETECT

=

•1000 =

For example, to program the CHRG pin to change state at

a battery charge current of 100mA, choose:

100V

100mA

R_ISTAT

=

= 1k

Once a time-out occurs and the voltage on the battery is

greater than the recharge threshold, the charge current

stops, and the CHRG output assumes a high impedance

state if it has not already done so.

Note: The end-of-charge (EOC) comparator that moni-

tors the I pin voltage for 100mV latches its decision.

STAT

Therefore, the ﬁrst time V

drops below 100mV (i.e.,

) while in constant voltage

ISTAT

Connecting the TIMER pin to ground disables the battery

charger.

I

drops below 100V/R

BAT

mode will toggle CHRG to a high impedance state. If, for

some reason, the charge current rises back above the

threshold, the CHRG pin will not resume the strong pull-

down state. The EOC latch can be reset by toggling the

SHDN pin or toggling the input power to the part. The EOC

latch will also be reset if the BAT pin voltage falls below

the recharge threshold.

CHRG Status Output Pin

When the charge cycle starts, the CHRG pin is pulled

to ground by an internal N-channel MOSFET capable of

driving an LED. When the charge current drops below a

programmable threshold while in constant-voltage mode,

thepinassumesahighimpedancestate(butchargecurrent

continues to ﬂow until the charge time elapses). If this

state is not reached before the end of the programmable

charge time, the pin will assume a high impedance state

when a time-out occurs.

4066fc

19

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

NTC Thermistor

value of R . This resistance is R . For a Vishay

NOM COLD

NTHS0603N02N1002J thermistor, this value is 28.2k

whichcorrespondstoapproximately0°C.Thehotandcold

comparators each have approximately 3°C of hysteresis

to prevent oscillation about the trip point. Grounding the

NTC pin can disable the NTC function.

Thebatterytemperatureismeasuredbyplacinganegative

temperature coefﬁcient (NTC) thermistor close to the bat-

tery pack. The NTC circuitry is shown in Figure 4. To use

this feature, connect the NTC thermistor (R ) between

NTC

the NTC pin and ground and a resistor (R

) from the

NOM

NTC pin to V . R

should be a 1% resistor with a

NTC NOM

Thermistors

value equal to the value of the chosen NTC thermistor at

25°C(thisvalueis10kforaVishayNTHS0603N02N1002J

thermistor). The LTC4066/LTC4066-1 go into hold mode

TheLTC4066/LTC4066-1NTCtrippointsweredesignedto

workwiththermistorswhoseresistance-temperaturechar-

acteristics follow Vishay Dale’s “R-T Curve 2”. The Vishay

NTHS0603N02N1002Jisanexampleofsuchathermistor.

However, Vishay Dale has many thermistor products that

followthe“R-TCurve2”characteristicinavarietyofsizes.

when the resistance (R ) of the NTC thermistor drops

HOT

to 0.41 times the value of R

or approximately 4.1k,

NOM

which should be at 50°C. The hold mode freezes the timer

and stops the charge cycle until the thermistor indicates a

return to a valid temperature. As the temperature drops,

the resistance of the NTC thermistor rises. The LTC4066/

LTC4066-1 are designed to go into hold mode when the

value of the NTC thermistor increases to 2.82 times the

Furthermore, anythermistorwhoseratioofR

toR

COLD

HOT

isabout7.0willalsowork(VishayDaleR-TCurve 2shows

a ratio of R to R of 2.815/0.4086 = 6.89).

COLD

HOT

V

NTC

V

NTC

LTC4066

15

0.74 • V

NTC

R

NOM

–

+

–

+

10k

121k

TOO_COLD

TOO_HOT

NTC

14

R

R1

13.3k

NTC

10k

–

+

–

+

TOO_HOT

0.29 • V

NTC

R

NTC

100k

+

–

+

–

NTC_ENABLE

0.1V

4066 F04a

4055 F03b

(4a)

(4b)

Figure 4. NTC Circuits

4066fc

20

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

Power conscious designs may want to use thermistors

whoseroomtemperaturevalueisgreaterthan10k. Vishay

Dale has a number of values of thermistor from 10k to

100k that follow the “R-T Curve 2.” Using these directly

in the manor spelled out previously in the NTC Thermistor

section will give temperature trip points of approximately

3°C and 47°C, a delta of 44°C. This delta in temperature

can be moved in either direction by changing the value of

The nearest 1% value for R

is 115k. This is the value

NOM

used to bias the NTC thermistor to get cold and hot trip

points of approximately 0°C and 44°C respectively. To

extend the delta between the cold and hot trip points,

a resistor (R1) can be added in series with R

Figure 3b). The values of the resistors are calculated as

follows:

(see

NTC

R

_COLD–R_HOT

R_NOM

=

R

with respect to R . Increasing R

will move

NOM

NTC

NOM

2.815 – 0.4086

bothtrippointstolowertemperatures.Likewiseadecrease

in R with respect to R will move the trip points to

0.4086

2.815 – 0.4086

⎛

⎝

⎞

⎟

⎠

R1=

• R_COLD–R_HOT–R

(

HOT

)

⎜

NOM

NTC

highertemperatures. TocalculateR

temperature for example, use the following equation:

forashifttolower

NOM

where R

COLD

is the value of the bias resistor, R

and

NOM

HOT

R

are the values of R

at the desired temperature

R_COLD

2.815

NTC

R_NOM

=

•R_NTCat 25°C

trip points. Continuing the example from before with a

desired hot trip point of 50°C:

where R

is the resistance ratio of R

at the desired

COLD

NTC

100k • 3.266 – 0.3602

R_COLD–R_HOT

2.815 – 0.4086

(

)

coldtemperaturetrippoint.Ifyouwanttoshiftthetrippoints

to higher temperatures, use the following equation:

R_NOM

=

2.815 – 0.4086

= 120.8kΩ, 121k nearest 1%

R_HOT

0.4086

R_NOM

=

•R_NTCat 25°C

⎡

⎤

0.4086

2.815 – 0.4086

⎛

⎜

⎝

⎞

⎟

⎠

R1= 100k •

• 3.266 – 0.3602 – 0.3602

(

)

⎢

⎥

⎦

⎣

where R

is the resistance ratio of R

at the desired

HOT

NTC

= 13.3kΩ, 13.3k is nearest 1%

hot temperature trip point.

The ﬁnal solution is as shown if Figure 3b where R

=

NOM

Here is an example using a 100k R-T Curve 1 Thermistor

from Vishay Dale. The difference between the trip points

is 44°C, from before, and we want the cold trip point to

be 0°C, which would put the hot trip point at 44°C. The

121k, R1 = 13.3k and R

= 100k at 25°C.

NTC

Gas Gauge

R

needed is calculated as follows:

The extremely low impedance of the ideal diode between

BAT and OUT (typically 50mΩ) allows users to connect

all of their loads to the OUT pin. Such a conﬁguration puts

the LTC4066/LTC4066-1 in a unique position whereby it

can monitor all of the current that ﬂows into and out of the

NOM

R_COLD

2.815

3.266

R_NOM

=

•R_NTCat 25°C

•100kΩ = 116kΩ

2.815

battery. Two output pins, I

and POL, are provided to

STAT

enable users to monitor and integrate the battery current

for a true gas gauge function.

4066fc

21

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

Any time a battery is connected to the BAT pin and the

SHDN pin is low, the BAT pin current can be monitored

with the following equation:

voltage should not exceed approximately V – 0.5V (for

BAT

the typical minimum operating voltage for the ideal diode

this value would be 2.8V – 0.5V = 2.3V). Typically, it is this

secondcasethatisthelimitingsituationsinceV istypi-

BAT

V

ISTAT

I_BAT

=

•1000

cally lower than V

(while charging) and transient ideal

OUT

R_ISTAT

diode loads tend to be greater than typical charge currents

(causing a higher voltage on the I pin). Therefore,

STAT

where |I | is the absolute value of the BAT pin current,

BAT

choosing a value of R

based on the CHRG detection

ISTAT

V

is the voltage on the I

resistance from the I

pin and R

is the total

ISTAT

STAT

pin to ground.

current may limit the maximum ideal diode load current

that can be sensed accurately. Consider an example:

STAT

The POL pin has two states: high impedance and strong

pull-down. High impedance indicates that current is ﬂow-

ing from BAT to OUT (ideal diode function) and strong

pull-down indicates that current is ﬂowing from OUT to

BAT (charging). If an external ADC is used to convert the

a) Desired charge current = 850mA

b) Desired CHRG detection current = 100mA

c) Maximum transient ideal diode current = 1.5A

Calculate:

I

voltage, then the POL pin can be thought of as a

STAT

sign bit.

a) R

b) R

c) V

= (1V/850mA) • 50,000 = 59k

= 100V/100mA = 1k

PROG

ISTAT

When the ideal diode function is operating, the I

STAT

cannot monitor ideal diode load currents less than about

1mA. For any ideal diode load current less than 1mA, the

= 1.5A/1000 • 1k = 1.5V

ISTAT(MAX)

I

pin will source a constant current of approximately

STAT

Inthisexample,thereisnocommonmodeproblembecause

1μA.However,whenthebatterychargerfunctionisoperat-

ing, the I pin will continue to source one-thousandth

the maximum I

voltage (1.5V) is well below the 2.3V

STAT

minimum.However,if,insteadof100mA,thedesiredCHRG

of the battery charge current even if the charge current

drops to less than 1mA.

detection current was lowered to 40mA, then the desired

R

resistor would increase to 2.5k (100V/40mA) and

ISTAT

the maximum I

voltage would increase to 3.75V (as-

When choosing the value of R

, two details must be

STAT

ISTAT

suming no change in the 1.5A maximum ideal diode cur-

rent). Therefore, ideal diode currents greater than 920mA

(2.3V/2.5k • 1000) might not be reported accurately. To

calculate the maximum ideal diode current that will be

reported accurately:

considered. For the battery charger function, the value of

R

programsthechargecurrentbelowwhichtheCHRG

ISTAT

pin transitions to its high impedance state (see CHRG

Status Output Pin). Furthermore, the available common

moderangeontheI

pinneededtomaintainanaccurate

ISTAT

STAT

ratiobetweenI andI

islimited.Whencharging,the

BAT

V_BAT– 0.5V

I_DMON(MAX)

=

I

pin voltage should not exceed approximately V

STAT

OUT

R_ISTAT

– 0.5V. When the ideal diode is functioning, the I

STAT

4066fc

22

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

Current Limit Undervoltage Lockout

Suspend

An internal undervoltage lockout circuit monitors the

input voltage and disables the input current limit circuits

The LTC4066/LTC4066-1 can be put in suspend mode by

forcing the SUSP pin greater than 1.2V. In suspend mode

the ideal diode function from BAT to OUT is kept alive.

If power is applied to the OUT pin externally (i.e., a wall

adapterispresent)thenchargingwillbeunaffected.Current

drawn from the IN pin is reduced to 50μA. Suspend mode

is intended to comply with the USB Power Speciﬁcation

mode of the same name.

until V rises above the undervoltage lockout threshold.

IN

The current limit UVLO circuit has a built-in hysteresis of

125mV. Furthermore, to protect against reverse current in

the power MOSFET, the current limit UVLO circuit disables

the current limit (i.e., forces the input power path to a high

impedance state) if V

exceeds V . If the current limit

OUT

IN

UVLO comparator is tripped, the current limit circuits will

Selecting WALL Input Resistors

not come out of shutdown until V

falls 50mV below

OUT

the V voltage.

IN

TheWALLinputpinidentiﬁesthepresenceofawalladapter.

This information is used to disconnect the input pin, IN,

from the OUT pin in order to prevent back conduction to

whatever may be connected to the input. It also forces the

ACPR pin low when the voltage at the WALL pin exceeds

the input threshold. The WALL pin has a 1.225V rising

threshold and approximately 30mV of hysteresis.

Charger Undervoltage Lockout

AninternalundervoltagelockoutcircuitmonitorstheV

OUT

voltage and disables the battery charger circuits until

V

rises above the undervoltage lockout threshold. The

OUT

battery charger UVLO circuit has a built-in hysteresis of

125mV. Furthermore, to protect against reverse current

in the power MOSFET, the charger UVLO circuit keeps the

The wall adapter detection threshold is set by the follow-

ing equation:

chargershutdownifV exceedsV .IfthechargerUVLO

BAT

OUT

R1

R2

comparator is tripped, the charger circuits will not come

⎛

⎝

⎞

⎟

⎠

V_TH(Adapter) = V_WALL• 1+

⎜

out of shutdown until V

exceeds V by 50mV.

OUT

BAT

R1

R2

⎛

⎝

⎞

⎟

⎠

Shutdown

V_HYST(Adapter) = V_WALL(HYST)• 1+

⎜

The LTC4066/LTC4066-1 can be shutdown by forcing the

SHDN pin greater than 1.2V. In shutdown, the currents

drawn from IN, OUT and BAT are decreased to less than

2.5μA and the internal battery charge timer and end-of-

charge comparator output are reset. All power paths are

put in a high impedance state.

whereV (Adapter)isthewalladapterdetectionthreshold,

TH

V

is the WALL pin rising threshold (typically 1.225V),

WALL

R1 is the resistor from the wall adapter input to WALL and

R2 is the resistor from WALL to GND.

4066fc

23

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

Consider an example where the V (Adapter) is to be set

However, the approximate ambient temperature at which

the thermal feedback begins to protect the IC is:

TH

somewhere around 4.5V. Resistance on the WALL pin

should be kept relatively low (~10k) in order to prevent

false tripping of the wall comparator due to leakages as-

sociated with the switching element used to connect the

adapter to OUT. Pick R2 to be 10k and solve for R1:

T = 105°C – P • θ

A

D

JA

T = 105°C – (V

– V ) • I • θ

JA

A

OUT

BAT

Example:ConsideranLTC4066/LTC4066-1operatingfrom

a wall adapter with 5V at V providing 0.8A to a 3V

OUT

⎛ V_TH(Adapter)

⎞

⎠

R1= R2 •

– 1

⎟

⎜

Li-Ion battery. The ambient temperature above which the

LTC4066/LTC4066-1 will begin to reduce the 0.8A charge

current, is approximately:

⎝

V_WALL

4.5V

1.225V

⎛

⎜

⎝

⎞

⎠

R1= 10k •

– 1 = 10k • 2.67 = 26.7k

⎟

T = 105°C – (5V – 3V) • 0.8A • 37°C/W

A

The nearest 1% resistor is 26.7k. Therefore, R1 = 26.7k

and the rising trip point should be 4.50V.

T = 105°C – 1.6W • 37°C/W = 105°C – 59°C = 46°C

A

The LTC4066/LTC4066-1 can be used above 46°C, but the

charge current will be reduced below 0.8A. The charge

current at a given ambient temperature can be approxi-

mated by:

26.7k

10k

⎛

⎝

⎞

⎟

⎠

V_HYST(Adapter) ≈ 30mV • 1+

≈ 110.1mV

⎜

The hysteresis is going to be approximately 110mV for

this example.

105°C – T_A

I_BAT

=

V

_OUT– V_BAT• θ

(

)

JA

Power Dissipation

Consider the above example with an ambient tem-

perature of 55°C. The charge current will be reduced to

approximately:

The conditions that cause the LTC4066/LTC4066-1 to

reduce charge current due to the thermal protection

feedback can be approximated by considering the power

dissipated in the part. For high charge currents and a wall

105°C – 55°C

50°C

I_BAT

=

= 0.675A

adapter applied to V , the LTC4066/LTC4066-1 power

5V – 3V • 37°C/W 74°C/A

(

)

OUT

dissipation is approximately:

Board Layout Considerations

P = (V

– V ) • I

BAT BAT

D

OUT

In order to be able to deliver maximum charge current

under all conditions, it is critical that the Exposed Pad

on the backside of the LTC4066/LTC4066-1 package is

where P is the power dissipated, V

is the supply

BAT

D

OUT

voltage, V is the battery voltage and I is the battery

BAT

charge current. It is not necessary to perform any worst-

case power dissipation scenarios because the LTC4066/

LTC4066-1 will automatically reduce the charge current

to maintain the die temperature at approximately 105°C.

2

soldered to the board. Correctly soldered to a 2500mm

double-sided 1oz. copper board, the LTC4066/LTC4066-1

has a thermal resistance of approximately 37°C/W. Failure

4066fc

24

LTC4066/LTC4066-1

APPLICATIONS INFORMATION

to make thermal contact between the Exposed Pad on the

backside of the package and the copper board will result

in thermal resistances far greater than 37°C/W. As an

example, a correctly soldered LTC4066/LTC4066-1 can

deliver over 1A to a battery from a 5V supply at room

temperature. Without a backside thermal connection, this

number could drop to less than 500mA.

ceramic capacitors. Because of the self resonant and high

Qcharacteristicsofsometypesofceramiccapacitors,high

voltage transients can be generated under some start-up

conditions, such as connecting the charger input to a hot

power source. For more information, refer to Application

Note 88.

Stability

Furthermore, Pins 6 and 7 are “true No Connect” pins.

Therefore, they can be used to improve the amount of

metal used to connect to Pin 5 or Pin 8.

Theconstant-voltagemodefeedbackloopisstablewithout

any compensation when a battery is connected. However,

a 4.7μF capacitor with a 1Ω series resistor to GND is

recommended at the BAT pin to keep ripple voltage low

when the battery is disconnected.

V and Wall Adapter Bypass Capacitor

IN

Many types of capacitors can be used for input bypassing.

However,cautionmustbeexercisedwhenusingmultilayer

4066fc

25

LTC4066/LTC4066-1

PACKAGE DESCRIPTION

UF Package

24-Lead Plastic QFN (4mm × 4mm)

(Reference LTC DWG # 05-08-1697)

0.70 p0.05

4.50 p 0.05

3.10 p 0.05

2.45 p 0.05

(4 SIDES)

PACKAGE OUTLINE

0.25 p0.05

0.50 BSC

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS

BOTTOM VIEW—EXPOSED PAD

R = 0.115

PIN 1 NOTCH

R = 0.20 TYP OR

0.35 s 45o CHAMFER

0.75 p 0.05

4.00 p 0.10

(4 SIDES)

TYP

23 24

PIN 1

TOP MARK

(NOTE 6)

0.40 p 0.10

1

2

2.45 p 0.10

(4-SIDES)

(UF24) QFN 0105

0.200 REF

0.25 p 0.05

0.00 – 0.05

0.50 BSC

NOTE:

1. DRAWING PROPOSED TO BE MADE A JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGD-X)—TO BE APPROVED

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, IF PRESENT

5. EXPOSED PAD SHALL BE SOLDER PLATED

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

ON THE TOP AND BOTTOM OF PACKAGE

4066fc

26

LTC4066/LTC4066-1

PACKAGE DESCRIPTION

PF Package

24-Lead Plastic UTQFN (4mm × 4mm)

(Reference LTC DWG # 05-08-1748 Rev Ø)

0.70 p0.05

2.45 p 0.05

2.50 REF

4.50 p 0.05

3.10 p 0.05

2.45 p 0.05

PACKAGE OUTLINE

0.25 p0.05

0.50 BSC

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS

APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED

BOTTOM VIEW—EXPOSED PAD

R = 0.115

PIN 1 NOTCH

R = 0.20 TYP

OR 0.35 s 45o

CHAMFER

0.55 p 0.05

R = 0.05

TYP

4.00 p 0.10

23 24

PIN 1

TOP MARK

(NOTE 6)

0.40 p 0.10

1

2

2.45 p 0.10

4.00 p 0.10

2.50 REF

(PF24) UTQFN 0107

0.125 REF

0.25 p 0.05

0.00 – 0.05

0.50 BSC

NOTE:

1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE

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, IF PRESENT

5. EXPOSED PAD SHALL BE SOLDER PLATED

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

ON THE TOP AND BOTTOM OF PACKAGE

4066fc

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 representa-

tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

27

LTC4066/LTC4066-1

TYPICAL APPLICATION

USB Power Control Application with Wall Adapter Input

5V WALL

ADAPTER

INPUT

TO LDOs

REGs, ETC

4.7μF

1Ω*

4.7μF

10k 510Ω 510Ω

5V (NOM)

FROM USB

IN

OUT

BAT

CABLE V

BUS

4.7μF

1Ω*

CHRG

ACPR

WALL

R1

26.7k

+

Li-Ion

CELL

V

NTC

R

NTCBIAS

100k

NTC

R2

10k

R

NTC

LTC4066

100k

SHUTDOWN

SHDN

SUSP

HPWR

SUSPEND USB POWER

500mA/100mA SELECT

POL

STAT

TO ADC FOR

GAS GAUGE

I

TIMER

GND

INPUT CURRENT

LIMIT DISABLE

CLDIS

PROG

R

ISTAT

2k

CLPROG

R

0.15μF

4006 TA03

R

71.5k

*SERIES 1Ω RESISTOR ONLY

NEEDED FOR INDUCTIVE

INPUT SUPPLIES

PROG

CLPROG

2.1k

RELATED PARTS

PART NUMBER

Battery Chargers

LTC1733

DESCRIPTION

COMMENTS

Monolithic Lithium-Ion Linear Battery Charger

Lithium-Ion Linear Battery Charger in ThinSOT

Switch Mode Lithium-Ion Battery Charger

Monolithic Lithium-Ion Battery Pulse Charger

Standalone Charger with Programmable Timer, Up to 1.5A Charge Current

Simple ThinSOT Charger, No Blocking Diode, No Sense Resistor Needed

™

LTC1734

LTC1734L

LTC4002

Low Current Version of LTC1734; 50mA ≤ I

≤ 180mA

CHRG

Standalone, 4.7V ≤ V ≤ 24V, 500kHz Frequency, 3-Hour Charge Termination

IN

LTC4052

No Blocking Diode or External Power FET Required, ≤1.5A Charge Current

Standalone Charger with Programmable Timer, Up to 1.25A Charge Current

LTC4053

USB Compatible Monolithic Li-Ion Battery Charger

LTC4054

Standalone Linear Li-Ion Battery Charger with

Integrated Pass Transistor in ThinSOT

Thermal Regulation Prevents Overheating, C/10 Termination, C/10 Indicator,

Up to 800mA Charge Current

LTC4057

LTC4058

LTC4059

Lithium-Ion Linear Battery Charger

Up to 800mA Charge Current, Thermal Regulation, ThinSOT Package

C/10 Charge Termination, Battery Kelvin Sensing, 7% Charge Accuracy

Standalone 950mA Lithium-Ion Charger in DFN

900mA Linear Lithium-Ion Battery Charger

2mm × 2mm DFN Package, Thermal Regulation, Charge Current Monitor

Output

LTC4411/LTC4412 Low Loss PowerPath Controller in ThinSOT

Automatic Switching Between DC Sources, Load Sharing, Replaces ORing

Diodes

Power Management

LTC3405/LTC3405A 300mA (I ), 1.5MHz, Synchronous Step-Down

95% Efﬁciency, V = 2.7V to 6V, V

= 0.8V, I = 20μA, I < 1μA,

OUT Q SD

OUT

IN

DC/DC Converters

ThinSOT Package

LTC3406/LTC3406A 600mA (I ), 1.5MHz, Synchronous Step-Down

95% Efﬁciency, V = 2.5V to 5.5V, V

= 0.6V, I = 20μA, I < 1μA,

Q SD

OUT

IN

OUT

DC/DC Converters

ThinSOT Package

LTC3411

LTC3440

LTC3455

LTC4055

1.25A (I ), 4MHz, Synchronous Step-Down

95% Efﬁciency, V = 2.5V to 5.5V, V

= 0.8V, I = 60μA, I < 1μA,

Q SD

OUT

IN

DC/DC Converter

MS10 Package

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

95% Efﬁciency, V = 2.5V to 5.5V, V

= 2.5V, I = 25μA, I < 1μA,

Q SD

OUT

IN

DC/DC Converter

MS Package

Dual DC/DC Converter with USB Power Manager and Seamless Transition Between Power Sources: USB, Wall Adapter and Battery;

Li-Ion Battery Charger

95% Efﬁcient DC/DC Conversion

USB Power Controller and Battery Charger

Charges Single Cell Li-Ion Batteries Directly from a USB Port, Thermal

Regulation, 200mΩ Ideal Diode, 4mm × 4mm QFN16 Package

ThinSOT is a trademark of Linear Technology Corporation.

4066fc

LT 0108 REV C • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

28

●

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


型号：	LTC4066
厂家：	Linear
描述：	USB Power Controller and Li-Ion Linear Charger with Low Loss Ideal Diode USB电源控制器和锂离子电池线性充电器与低损耗理想二极管电池二极管控制器
文件：	总28页 (文件大小：312K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LTC4066 [Linear]

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