Linear Technology LTC4085, LTC4085EDE Datasheet

LTC4085

1

4085fa

I

LOAD

(mA)

0

600

500

400

300

200

100

0

–100

300 500

4085 TA01b

100 200

400 600

CURRENT (mA)

I

LOAD

I

IN

I

BAT

(CHARGING)

I

BAT

(DISCHARGING)

WALL = 0V

USB Power Manager with

Ideal Diode Controller and

Li-Ion Charger

The LTC®4085 is a USB power manager and Li-Ion battery
charger designed for portable battery-powered applica­tions. The part controls the total current used by the USB
peripheral for operation and battery charging. The total
input current can be limited to 20% or 100% of a pro­grammed value up to 1.5A (typically 100mA or 500mA).
Battery charge current is automatically reduced such that
the sum of the load current and charge current does not
exceed the programmed input current limit.

The LTC4085 includes a complete constant-current/con­stant-voltage linear charger for single cell Li-ion batteries.
The fl oat voltage applied to the battery is held to a tight

0.8% tolerance, and charge current is programmable using
an external resistor to ground. An end-of-charge status
output

⎯C⎯H⎯R⎯

G indicates full charge. Total charge time is
programmable by an external capacitor to ground. When
the battery drops 100mV below the fl oat voltage, automatic
recharging of the battery occurs. Also featured is an NTC
thermistor input used to monitor battery temperature
while charging.

The LTC4085 is available in a 14-lead low profi le 4mm ×
3mm DFN package.

■

Portable USB Devices: Cameras, MP3 Players, PDAs

■

Seamless Transition Between Input Power Sources:

Li-Ion Battery, USB and 5V Wall Adapter

■

215mΩ Internal Ideal Diode Plus Optional External

Ideal Diode Controller Provide Low Loss PowerPath

TM

When Wall Adapter/USB Input Not Present

■

Load Dependent Charging Guarantees Accurate USB

Input Current Compliance

■

Constant-Current/Constant-Voltage Operation with

Thermal Feedback to Maximize Charging Rate Without
Risk of Overheating*

■

Selectable 100% or 20% Input Current Limit

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

■

Battery Charge Current Independently Programmable

Up to 1.2A

■

Preset 4.2V Charge Voltage with 0.8% Accuracy

■

C/10 Charge Current Detection Output

■

NTC Thermistor Input for Temperature Qualifi ed Charging

■

Tiny (4mm × 3mm × 0.75mm) 14-Lead DFN Package

APPLICATIO S

U

FEATURES DESCRIPTIO

U

TYPICAL APPLICATIO

U

IN

SUSP

HPWR

PROG

CLPROG

NTC

V

NTC

WALL

ACPR

OUT

GATE

BAT

CHRG

TIMER

LTC4085

GND

+

0.1µF

4.7µF

TO LDOs,
REGs, ETC

10k

10k2k100k

5V WALL

ADAPTER

INPUT

5V (NOM)

FROM USB

CABLE V

BUS

4.7µF

SUSPEND USB POWER

100mA 500mA SELECT

1k

510Ω

4085 TA01

*

* OPTIONAL - TO LOWER

IDEAL DIODE IMPEDANCE

I

IN

I

LOAD

I

BAT

, 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, 6700364.
Other patents pending.

Input and Battery Current vs Load Current

R

PROG

= 100k, R

CLPROG

= 2k

LTC4085

2

4085fa

(Notes 1, 2, 3, 4, 5)

Terminal Voltage

IN, OUT

t < 1ms and Duty Cycle < 1% ................... –0.3V to 7V

Steady State ............................................. –0.3V to 6V

BAT,

⎯C⎯H⎯R⎯

G, HPWR, SUSP, WALL, ⎯A⎯C⎯P⎯R ..... –0.3V to 6V

NTC, TIMER, PROG, CLPROG .......–0.3V to (V

CC

+ 0.3V)

Pin Current (Steady State)

IN, OUT, BAT (Note 6) ..............................................2.5A

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

Maximum Operating Junction Temperature .......... 110°C

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

The

●

indicates specifi cations which apply over the full operating

temperature range, otherwise specifi cations are at TA = 25°C. VIN = 5V, V

BAT

= 3.7V, HPWR = 5V, WALL = 0V, R

PROG

= 100k,

R

CLPROG

= 2k, unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

IN

Input Supply Voltage IN and OUT

4.35 5.5 V

V

BAT

Input Voltage BAT

4.3 V

I

IN

Input Supply Current I

BAT

= 0 (Note 7)
Suspend Mode; SUSP = 5V
Suspend Mode; SUSP = 5V, WALL = 5V,
V

OUT

= 4.8V

●

●

●

0.5
50
60

1.2
100
110

mA

μA
μA

I

OUT

Output Supply Current V

OUT

= 5V, VIN = 0V, NTC = V

NTC

●

0.7 1.4 mA

I

BAT

Battery Drain Current V

BAT

= 4.3V, Charging Stopped
Suspend Mode; SUSP = 5V
V

IN

= 0V, BAT Powers OUT, No Load

●

●

●

15
22
60

27
35

100

μA
μA
μA

V

UVLO

Input or Output Undervoltage Lockout VIN Powers Part, Rising Threshold

V

OUT

Powers Part, Rising Threshold

●

●

3.6

2.75

3.8

2.9543.15

V
V

ΔV

UVLO

Input or Output Undervoltage Lockout VIN Rising – VIN Falling

or V

OUT

Rising – V

OUT

Falling

130 mV

Current Limit

I

LIM

Current Limit R

CLPROG

= 2k (0.1%), HPWR = 5V

R

CLPROG

= 2k (0.1%), HPWR = 0V

●

●

475

90

500
100

525
110

mA
mA

I

IN(MAX)

Maximum Input Current Limit (Note 8) 2.4 A

R

ON

ON Resistance VIN to V

OUT

I

OUT

= 100mA Load 215 mΩ

ELECTRICAL CHARACTERISTICS

ABSOLUTE AXI U RATI GS

W

WW

U

ORDER PART NUMBER

DE PART MARKING

Consult LTC Marketing for parts specifi ed with wider operating temperature ranges.

4085

PACKAGE/ORDER I FOR ATIO

UUW

T

JMAX

= 125°C, θJA = 40°C/W

EXPOSED PAD (PIN 15) IS GND, MUST BE CONNECTED TO PCB

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/

1

2

3

4

5

6

7

14

13

12

11

10

9

8

BAT

GATE

PROG

CHRG

ACPR

V

NTC

NTC

IN

OUT

CLPROG

HPWR

SUSP

TIMER

WALL

TOP VIEW

15

DE PACKAGE

14-LEAD (4mm × 3mm) PLASTIC DFN

LTC4085EDE

LTC4085

3

4085fa

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

CLPROG

CLPROG Pin Voltage R

PROG

= 2k

R

PROG

= 1k

●

●

0.98

0.98

1
1

1.02

1.02

V
V

I

SS

Soft Start Inrush Current IN or OUT 5 mA/μs

V

CLEN

Input Current Limit Enable Threshold
Voltage

(VIN – V

OUT

) VIN Rising

(V

IN

– V

OUT

) VIN Falling

20

-80

50

-60

80

-20

mV
mV

Battery Charger

V

FLOAT

Regulated Output Voltage I

BAT

= 2mA

I

BAT

= 2mA, (0°C – 85°C)

4.165

4.158

4.2

4.2

4.235

4.242

V
V

I

BAT

Current Mode Charge Current R

PROG

= 100k (0.1%), No Load

R

PROG

= 50k (0.1%), No Load

●

●

465
920

500

1000

535

1080

mA
mA

I

BAT(MAX)

Maximum Charge Current (Note 8) 1.5 A

V

PROG

PROG Pin Voltage R

PROG

= 100k

R

PROG

= 50k

●

●

0.98

0.98

1
1

1.02

1.02

V
V

k

EOC

Ratio of End-of-Charge Current to
Charge Current

V

BAT

= V

FLOAT

(4.2V)

●

0.085 0.1 0.11 mA/mA

I

TRIKL

Trickle Charge Current V

BAT

= 2V, R

PROG

= 100k (0.1%) 40 50 60 mA

V

TRIKL

Trickle Charge Threshold Voltage

●

2.8 2.9 3 V

V

CEN

Charger Enable Threshold Voltage (V

OUT

– V

BAT

) Falling; V

BAT

= 4V

(V

OUT

– V

BAT

) Rising; V

BAT

= 4V

55
80

mV
mV

V

RECHRG

Recharge Battery Threshold Voltage V

FLOAT

– V

RECHRG

●

60 100 130 mV

t

TIMER

TIMER Accuracy V

BAT

= 4.3V -10 10 %

Recharge Time Percent of Total Charge Time 50 %

Low Battery Trickle Charge Time Percent of Total Charge Time, V

BAT

< 2.8V 25 %

T

LIM

Junction Temperature in Constant
Temperature Mode

105 °C

Internal Ideal Diode

R

FWD

Incremental Resistance, VON Regulation I

BAT

= 100mA 125 mΩ

R

DIO(ON)

ON Resistance V

BAT

to V

OUT

I

BAT

= 600mA 215 mΩ

V

FWD

Voltage Forward Drop (V

BAT

– V

OUT

)I

BAT

= 5mA

I

BAT

= 100mA

I

BAT

= 600mA

●

10 30

55

160

50 mV

mV
mV

V

OFF

Diode Disable Battery Voltage 2.8 V

I

FWD

Load Current Limit, for VON Regulation 550 mA

I

D(MAX)

Diode Current Limit 2.2 A

External Ideal Diode

V

FWD,EDA

External Ideal Diode Forward Voltage V

GATE

= 1.85V; I

GATE

= 0 20 mV

Logic

V

OL

Output Low Voltage ⎯C⎯H⎯R⎯G, ⎯A⎯C⎯P⎯RI

SINK

= 5mA

●

0.1 0.25 V

V

IH

Input High Voltage SUSP, HPWR Pin

●

1.2 V

V

IL

Input Low Voltage SUSP, HPWR Pin

●

0.4 V

I

PULLDN

Logic Input Pull-Down Current SUSP, HPWR 2 μA

The

●

indicates specifi cations which apply over the full operating

temperature range, otherwise specifi cations are at T

A

= 25°C. VIN = 5V, V

BAT

= 3.7V, HPWR = 5V, WALL = 0V, R

PROG

= 100k,

R

CLPROG

= 2k, unless otherwise noted.

ELECTRICAL CHARACTERISTICS

LTC4085

4

4085fa

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

CHG(SD)

Charger Shutdown Threshold Voltage
on TIMER

●

0.15 0.4 V

I

CHG(SD)

Charger Shutdown Pull-Up Current
on TIMER

V

TIMER

= 0V

●

514 μA

V

WAR

Absolute Wall Input Threshold Voltage V

WALL

Rising Threshold

●

4.15 4.25 4.35 V

V

WAF

Absolute Wall Input Threshold Voltage V

WALL

Falling Threshold 3.12 V

V

WDR

Delta Wall Input Threshold Voltage V

WALL

– V

BAT

Rising Threshold 75 mV

V

WDF

Delta Wall Input Threshold Voltage V

WALL

– V

BAT

Falling Threshold

●

02540 mV

I

WALL

Wall Input Current V

WALL

= 5V 75 150 μA

NTC

V

VNTC

V

NTC

Bias Voltage I

VNTC

= 500μA

●

4.4 4.85 V

I

NTC

NTC Input Leakage Current V

NTC

= 1V 0 ±1 μA

V

COLD

Cold Temperature Fault Threshold
Voltage

Rising Threshold
Hysteresis

0.74 • V

VNTC

0.02 • V

VNTC

V
V

V

HOT

Hot Temperature Fault Threshold
Voltage

Falling Threshold
Hysteresis

0.29 • V

VNTC

0.01 • V

VNTC

V
V

V

DIS

NTC Disable Voltage NTC Input Voltage to GND (Falling)

Hysteresis

●

75 100

35

125 mV

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.

Note 2: V

CC

is the greater of VIN, V

OUT

or V

BAT

.

Note 3: All voltage values are with respect to GND.
Note 4: This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions. Junction
temperatures will exceed 125°C when overtemperature protection is
active. Continuous operation above the specifi ed maximum operating
junction temperature may result in device degradation or failure.

Note 5: The LTC4085E is guaranteed to meet specifi ed performance from
0° to 85°C. Specifi cations over the –40°C to 85°C operating temperature
range are assured by design, characterization and correlation with
statistical process controls.

Note 6: Guaranteed by long term current density limitations.
Note 7: Total input current is equal to this specifi cation plus 1.002 • I

BAT

where I

BAT

is the charge current.

Note 8: Accuracy of programmed current may degrade for currents greater
than 1.5A.

The

●

indicates specifi cations which apply over the full operating

temperature range, otherwise specifi cations are at T

A

= 25°C. VIN = 5V, V

BAT

= 3.7V, HPWR = 5V, WALL = 0V, R

PROG

= 100k,

R

CLPROG

= 2k, unless otherwise noted.

ELECTRICAL CHARACTERISTICS

LTC4085

5

4085fa

TEMPERATURE (°C)

–50

V

PROG

(V)

0.995

1.000

1.005

25

75

4085 G07

0.990

0.985

0.980
–25 0 50

1.010

1.015

1.020

100

VIN = 5V
V

BAT

= 4.2V

R

PROG

= 100k

R

CLPROG

= 2k

I

BAT

(mA)

0

4.00

V

FLOAT

(V)

4.05

4.10

4.15

4.20

4.25

4.30

200 400 600 800

4085 G08

1000

R

PROG

= 34k

TEMPERATURE (°C)

–50

VFLOAT (V)

4.195

4.200

4.205

25

75

4085 G09

4.190

4.185

4.180
–25 0 50

4.210

4.215

4.220

100

VIN = 5V
I

BAT

= 2mA

TEMPERATURE (°C)

–50

0

I

IN

(µA)

100

300

400

500

50

900

4085 G01

200

0

–25

75

25 100

600

700

800

VIN = 5V
V

BAT

= 4.2V

R

PROG

= 100k

R

CLPROG

= 2k

TEMPERATURE (°C)

–50

70

60

50

40

30

20

10

0

25 75

4085 G02

25 0

50 100

I

IN

(µA)

VIN = 5V
V

BAT

= 4.2V

R

PROG

= 100k

R

CLPROG

= 2k

SUSP = 5V

TEMPERATURE (°C)

–50

0

I

BAT

(µA)

20

40

60

–25

0

25 50

4085 G03

75

80

100

10

30

50

70

90

100

VIN = 0V
V

BAT

= 4.2V

TEMPERATURE (°C)

–50

475

I

IN

(mA)

485

495

505

515

525

–25

02550

4085 G04

75 100

VIN = 5V
V

BAT

= 3.7V

R

PROG

= 100k

R

CLPROG

= 2k

TEMPERATURE (°C)

–50

I

IN

(mA)

92

96

100

–25

0

25 50

4085 G05

75

104

108

110

90

94

98

102

106

100

VIN = 5V
V

BAT

= 3.7V

R

PROG

= 100k

R

CLPROG

= 2k

TEMPERATURE (°C)

–50

0

V

CLPROG

(V)

0.2

0.4

0.6

0.8

1.2

–25

02550

4085 G06

75 100

1.0

VIN = 5V
R

CLPROG

= 2k

HPWR = 5V

HPWR = 0V

Input Supply Current
vs Temperature

Input Supply Current vs
Temperature (Suspend Mode)

Battery Drain Current
vs Temperature
(BAT Powers OUT, No Load)

Input Current Limit
vs Temperature, HPWR = 5V

Input Current Limit
vs Temperature, HPWR = 0V

CLPROG Pin Voltage
vs Temperature

PROG Pin Voltage
vs Temperature V

FLOAT

Load Regulation

Battery Regulation (Float)
Voltage vs Temperature

TYPICAL PERFOR A CE CHARACTERISTICS

UW

TA = 25°C unless otherwise noted.

LTC4085

6

4085fa

TEMPERATURE (°C)

–50

I

BAT

(mA)

400

500

600

25 75

4085 G12

300

200

–25 0

50 100 125

100

0

VIN = 5V
V

BAT

= 3.5V

θ

JA

= 50°C/W

TEMPERATURE (°C)

–50

125

R

ON

(mΩ)

150

175

200

225

275

–25

02550

4085 G10

75 100

250

VIN = 4.5V

VIN = 5.5V

I

LOAD

= 400mA

VIN = 5V

TIME (min)

0

0

I

BAT

(mA)

100

200

300

400

500

600

0

V

BAT

AND V

CHRG

(V)

1

2

3

4

5

6

50 100 150 200

4085 G11

400mAhr CELL
V

IN

= 5V

R

PROG

= 100k

R

CLPROG

= 2.1k

C/10

TERMINATION

CHRG

V

BAT

I

BAT

V

BAT

(V)

0

0

I

BAT

(mA)

100

300

400

500

1

2

2.5 4.5

4085 G13

200

0.5 1.5

3

3.5

4

600

VIN = 5V
V

OUT

= NO LOAD

R

PROG

= 100k

R

CLPROG

= 2k

HPWR = 5V

V

BAT

(V)

0

0

I

BAT

(mA)

20

60

80

100

1

2

2.5 4.5

4085 G14

40

0.5 1.5

3

3.5

4

120

VIN = 5V
V

OUT

= NO LOAD

R

PROG

= 100k

R

CLPROG

= 2k

HPWR = 0V

V

FWD

(mV)

0

0

I

OUT

(mA)

100

300

400

500

1000

700

50

100

4085 G15

200

800

900

600

150

200

V

BAT

= 3.7V

V

IN

= 0V

–50°C

0°C

50°C

100°C

V

FWD

(mV)

0

0

I

OUT

(mA), R

DIO

(mΩ)

100

300

400

500

1000

700

50

100

4085 G16

200

800

900

600

150

200

V

BAT

= 3.7V

V

IN

= 0V

R

DIO

I

OUT

0

3000

4000

5000

80

4085 G17

2000

1000

2500

3500

4500

1500

500

0

20

40

60

100

V

FWD

(mV)

I

OUT

(mA)

V

BAT

= 3.7V

V

IN

= 0V

Si2333 PFET

–50°C

0°C

50°C

100°C

0

3000

4000

5000

80

2000

1000

2500

3500

4500

1500

500

0

20

40

60

100

V

FWD

(mV)

I

OUT

(mA)

V

BAT

= 3.7V

V

IN

= 0V

Si2333 PFET

Input RON vs Temperature

Battery Current and Voltage
vs Time

Charge Current vs Temperature
(Thermal Regulation)

Charging from USB, I

BAT

vs V

BAT

Charging from USB, Low Power,
I

BAT

vs V

BAT

Ideal Diode Current vs Forward
Voltage and Temperature
(No External Device)

Ideal Diode Resistance and
Current vs Forward Voltage
(No External Device)

Ideal Diode Current vs Forward
Voltage and Temperature with
External Device

Ideal Diode Resistance and
Current vs Forward Voltage with
External Device

TYPICAL PERFOR A CE CHARACTERISTICS

UW

TA = 25°C unless otherwise noted.

LTC4085

7

4085fa

Input Connect Waveforms

Input Disconnect Waveforms

Response to HPWR

Wall Connect Waveforms,
V

IN

= 0V

TYPICAL PERFOR A CE CHARACTERISTICS

UW

TA = 25°C unless otherwise noted.

1ms/DIV

V

IN

5V/DIV

V

OUT

5V/DIV

I

IN

0.5A/DIV
I

BAT

0.5A/DIV

4085 G19

V

BAT

= 3.85V

I

OUT

= 100mA

1ms/DIV

V

IN

5V/DIV

V

OUT

5V/DIV

I

IN

0.5A/DIV
I

BAT

0.5A/DIV

4085 G20

V

BAT

= 3.85V

I

OUT

= 100mA

100µs/DIV

HPWR

5V/DIV

I

IN

0.5A/DIV

I

BAT

0.5A/DIV

4085 G21

V

BAT

= 3.85V

I

OUT

= 50mA

1ms/DIV

WALL

5V/DIV

V

OUT

5V/DIV

I

WALL

0.5A/DIV
I

BAT

0.5A/DIV

4085 G22

V

BAT

= 3.85V

I

OUT

= 100mA

R

PROG

= 100k

1ms/DIV

WALL

5V/DIV

V

OUT

5V/DIV

I

WALL

0.5A/DIV
I

BAT

0.5A/DIV

4085 G23

V

BAT

= 3.85V

I

OUT

= 100mA

R

PROG

= 100k

100µs/DIV

SUSP

5V/DIV

V

OUT

5V/DIV

I

IN

0.5A/DIV

I

BAT

0.5A/DIV

4085 G24

V

BAT

= 3.85V

I

OUT

= 50mA

Wall Disconnect Waveforms,
V

IN

= 0V

Response to Suspend

LTC4085

8

4085fa

PI FU CTIO S

UUU

IN (Pin 1): Input Supply. Connect to USB supply, V

BUS

.
Input current to this pin is limited to either 20% or 100%
of the current programmed by the CLPROG pin as deter­mined by the state of the HPWR pin. Charge current (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.

OUT (Pin 2): Voltage Output. This pin is used to provide
controlled power to a USB device from either USB V

BUS

(IN) or the battery (BAT) when the USB is not present.
This pin can also be used as an input for battery charging
when the USB is not present and a wall adapter is applied
to this pin. OUT should be bypassed with at least 4.7μF
to GND.

CLPROG (Pin 3): Current Limit Program and Input Cur­rent Monitor. Connecting a resistor, R

CLPROG

, to ground
programs the input to output current limit. The current
limit is programmed as follows:

IA

V

R

CL

CLPROG

()=

1000

In USB applications the resistor R

CLPROG

should be set

to no less than 2.1k.

The voltage on the CLPROG pin is always proportional to
the current fl owing through the IN to OUT power path.
This current can be calculated as follows:

IA

V

R

IN

CLPROG

CLPROG

() •= 1000

HPWR (Pin 4): High Power Select. This logic input is used
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 2μA pull-down is internally applied to this pin to
ensure it is low at power up when the pin is not being
driven externally.

SUSP (Pin 5): 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 specifi cation 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
reset the charge timer if V

OUT

is less than V

BAT

while in

suspend mode. If V

OUT

is kept greater than V

BAT

, such as

when a wall adapter is present, the charge timer will not
be reset when the part is put in suspend. A 2μA pull-down
is internally applied to this pin to ensure it is low at power
up when the pin is not being driven externally.

TIMER (Pin 6): Timer Capacitor. Placing a capacitor, C

TIMER

,

to GND sets the timer period. The timer period is:

t Hours

C R Hours

Fk

TIMER

TIMER PROG

()

••

.•

=

µ

3

0 1 100

Charge time is increased if charge current is reduced
due to undervoltage current limit, load current, thermal
regulation and current limit selection (HPWR).

Shorting the TIMER pin to GND disables the battery
charging functions.