Linear LTC4054ES5-4.2, LTC4054XES5-4.2 Schematic

FEATURES

■

Programmable Charge Current Up to 800mA

■

No MOSFET, Sense Resistor or Blocking Diode Required

■

Complete Linear Charger in ThinSOTTM Package for Single Cell Lithium-Ion Batteries

■

Constant-Current/Constant-Voltage Operation with Thermal Regulation* to Maximize Charge Rate Without Risk of Overheating

■

Charges Single Cell Li-Ion Batteries Directly from USB Port

■

Preset 4.2V Charge Voltage with ±1% Accuracy

■

Charge Current Monitor Output for Gas Gauging*

■

Automatic Recharge

■

Charge Status Output Pin

■

C/10 Charge Termination

■

25µA Supply Current in Shutdown

■

2.9V Trickle Charge Threshold (LTC4054)

■

Available Without Trickle Charge (LTC4054X)

■

Soft-Start Limits Inrush Current

■

Available in 5-Lead SOT-23 Package

U

APPLICATIO S

■

Cellular Telephones, PDAs, MP3 Players

■

Charging Docks and Cradles

■

Bluetooth Applications

LTC4054-4.2/LTC4054X-4.2

Standalone Linear

Li-Ion Battery Charger with

Thermal Regulation in ThinSOT

U

DESCRIPTIO

The LTC®4054 is a complete constant-current/constantvoltage linear charger for single cell lithium-ion batteries. Its ThinSOT package and low external component count make the LTC4054 ideally suited for portable applications. Furthermore, the LTC4054 is specifically designed to work within USB power specifications.

No external sense resistor is needed, and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient temperature. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The LTC4054 automatically terminates the charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached.

When the input supply (wall adapter or USB supply) is removed, the LTC4054 automatically enters a low current state, dropping the battery drain current to less than 2µA. The LTC4054 can be put into shutdown mode, reducing the supply current to 25µA.

Other features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage.

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

ThinSOT is a trademark of Linear Technology Corporation. *U.S.Patent No. 6,522,118

TYPICAL APPLICATIO

600mA Single Cell Li-Ion Charger

V

IN

4.5V TO 6.5V

1µF

4

V

CC

LTC4054-4.2

PROG

GND

2

BAT

3

5

1.65k

U

600mA

4.2V Li-Ion BATTERY

405442 TA01a

Complete Charge Cycle (750mAh Battery)

700

CONSTANT

CURRENT

600

CONSTANT POWER

500

400

300

200

CHARGE CURRENT (mA)

VCC = 5V

= 130°C/W

θ

JA

100

R

= 1.65k

PROG

= 25°C

T

A

0

0.5 1.0 2.0

0.25 0.75 1.25 1.75

0

TIME (HOURS)

CHARGE

TERMINATED

CONSTANT

VOLTAGE

1.5

4.75

4.50

BATTERY VOLTAGE (V)

4.25

4.00

3.75

3.50

3.25

3.00

405442 TAO1b

405442xf

1

LTC4054-4.2/LTC4054X-4.2

PACKAGE/ORDER I FOR ATIO

UU

W

CHRG 1

GND 2

TOP VIEW

S5 PACKAGE

5-LEAD PLASTIC TSOT-23

BAT 3

5 PROG

4 V

CC

WWWU

ABSOLUTE AXI U RATI GS

(Note 1)

Input Supply Voltage (VCC) ....................... –0.3V to 10V

PROG............................................. –0.3V to VCC + 0.3V

BAT.............................................................. –0.3V to 7V

CHRG........................................................ –0.3V to 10V

BAT Short-Circuit Duration .......................... Continuous

BAT Pin Current ................................................. 800mA

PROG Pin Current................................................ 800µA

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

Operating Ambient Temperature Range

(Note 2) .............................................. –40°C to 85°C

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

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

ORDER PART

NUMBER

LTC4054ES5-4.2 LTC4054XES5-4.2

S5 PART MARKING

T

= 125°C, (θJA = 80°C/ W TO

JMAX

150°C/W DEPENDING ON PC BOARD LAYOUT)

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

(N0TE 3)

LTH7 LTADY

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

CC

I

CC

V

FLOAT

I

BAT

I

TRIKL

V

TRIKL

V

TRHYS

V

UV

V

UVHYS

V

MSD

V

ASD

I

TERM

V

PROG

I

CHRG

V

CHRG

∆V

RECHRG

Input Supply Voltage ● 4.25 6.5 V Input Supply Current Charge Mode (Note 4), R

Standby Mode (Charge Terminated) Shutdown Mode (R

< V

V

CC

BAT

Regulated Output (Float) Voltage 0°C ≤ TA ≤ 85°C, I BAT Pin Current R

Trickle Charge Current V Trickle Charge Threshold Voltage R Trickle Charge Hysteresis Voltage R VCC Undervoltage Lockout Threshold From VCC Low to High ● 3.7 3.8 3.92 V VCC Undervoltage Lockout Hysteresis ● 150 200 300 mV Manual Shutdown Threshold Voltage PROG Pin Rising ● 1.15 1.21 1.30 V

VCC – V

C/10 Termination Current Threshold R

PROG Pin Voltage R CHRG Pin Weak Pull-Down Current V CHRG Pin Output Low Voltage I Recharge Battery Threshold Voltage V

Lockout Threshold Voltage VCC from Low to High 70 100 140 mV

BAT

= 10k, Current Mode ● 93 100 107 mA

PROG

R

= 2k, Current Mode ● 465 500 535 mA

PROG

Standby Mode, V Shutdown Mode (R Sleep Mode, V

< V

BAT

TRIKL

= 10k, V

PROG

= 10k (Note 5) 60 80 110 mV

PROG

PROG Pin Falling

V

from High to Low 5 30 50 mV

CC

= 10k (Note 6) ● 0.085 0.10 0.115 mA/mA

PROG

= 2k ● 0.085 0.10 0.115 mA/mA

R

PROG

= 10k, Current Mode ● 0.93 1.0 1.07 V

PROG

= 5V 8 20 35 µA

CHRG

= 5mA 0.35 0.6 V

CHRG

- V

FLOAT

RECHRG

PROG

, or VCC < VUV)

BAT

= 4.2V ● 0 –2.5 –6 µA

BAT

PROG

= 0V ±1 ±2 µA

CC

, R

PROG

Rising (Note 5) 2.8 2.9 3.0 V

BAT

= 10k ● 300 2000 µA

PROG

Not Connected, ● 25 50 µA

= 40mA 4.158 4.2 4.242 V

Not Connected) ±1 ±2 µA

= 2k (Note 5) ● 20 45 70 mA

● 200 500 µA

● 0.9 1.0 1.1 V

100 150 200 mV

2

405442xf

LTC4054-4.2/LTC4054X-4.2

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

T

LIM

Junction Temperature in Constant 120 °C Temperature Mode

R

ON

t

SS

t

RECHARGE

t

TERM

I

PROG

Note 1: Absolute Maximum Ratings are those values beyond which the life of the device may be impaired.

Note 2: The LTC4054E-4.2 and the LTC4054XE-4.2 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.

Power FET “ON” Resistance 600 mΩ (Between V

Soft-Start Time I Recharge Comparator Filter Time V Termination Comparator Filter Time I

and BAT)

CC

= 0 to I

BAT

High to Low 0.75 2 4.5 ms

BAT

Falling Below I

BAT

=1000V/R

BAT

PROG

/10 400 1000 2500 µs

CHG

100 µs

PROG Pin Pull-Up Current 3 µA

Note 4: Supply current includes PROG pin current (approximately 100µA) but does not include any current delivered to the battery through the BAT pin (approximately 100mA).

Note 5: This parameter is not applicable to the LTC4054X. Note 6: I

is expressed as a fraction of measured full charge current

TERM

with indicated PROG resistor.

Note 3: See Thermal Considerations.

UW

TYPICAL PERFOR A CE CHARACTERISTICS

PROG Pin Voltage vs Supply Voltage(Constant Current Mode)

1.015 VCC = 5V

= 4V

V

BAT

1.010

T

= 25°C

A

= 10k

R

PROG

1.005

(V)

1.000

PROG

V

0.995

0.990

0.985

4.0

5.0 5.5 6.0

4.5 VCC (V)

6.5 7.0

4054 G01

PROG Pin Voltage vs Temperature

1.0100 VCC = 5V

= 4V

V

1.0075

1.0050

1.0025

(V)

1.0000

PROG

V

0.9975

0.9950

0.9925

0.9900

BAT

R

= 10k

PROG

–50 –25 0 5025

TEMPERATURE (°C)

Charge Current vs PROG Pin Voltage

600

VCC = 5V

= 25°C

T

A

500

R

= 2k

PROG

400

(mA)

300

BAT

I

200

100

75

100

4054 G02

0

0.25 0.50 0.75 1.00

0

V

PROG

(V)

1.25

4054 G03

405442xf

3

LTC4054-4.2/LTC4054X-4.2

UW

TYPICAL PERFOR A CE CHARACTERISTICS

PROG Pin Pull-Up Current vs Temperature and Supply Voltage

3.7 V

= 4.3V

BAT

= 0V

V

PROG

3.5

3.3

(µA)

3.1

2.9

2.7

2.5

–50

VCC = 6.5V

–25 0

50 100 125

25 75

TEMPERATURE (°C)

PROG

I

Regulated Output (Float) Voltage vs Charge Current

4.26 VCC = 5V

4.24

= 25°C

T

A

= 1.25k

R

PROG

4.22

4.20

(V)

4.18

FLOAT

V

4.16

4.14

4.12

4.10

0

200 300 400 500 700600

100

I

(mA)

BAT

VCC = 4.2V

4054 G04

4054 G07

PROG Pin Current vs PROG Pin Voltage (Pull-Up Current)

3.5

3.0

2.5

2.0

(µA)

1.5

PROG

I

1.0

VCC = 5V

0.5 = 4.3V

V

BAT

= 25°C

T

A

0

2.0

2.2 2.3 2.4 2.5 2.6

2.1

V

PROG

(V)

Regulated Output (Float) Voltage vs Temperature

4.215 VCC = 5V

= 10k

R

PROG

4.210

4.205

(V)

4.200

FLOAT

V

4.195

4.190

4.185

–50

050

–25 25 75

TEMPERATURE (°C)

4054 G05

4054 G08

100

PROG Pin Current vs PROG Pin Voltage (Clamp Current)

0

–50

–100

–150

(µA)

–200

PROG

I

–250

–300

VCC = 5V

–350

–400

= 4.3V

V

BAT

= 25°C

T

A

3.0 4.0

2.5 3.5 4.5 5.5

2.0 (V)

V

PROG

Regulated Output (Float) Voltage vs Supply Voltage

4.215 TA = 25°C

= 10k

R

PROG

4.210

4.205

(V)

4.200

FLOAT

V

4.195

4.190

4.185

4.0

5.0 5.5 6.0

4.5 VCC (V)

5.0

4054 G06

6.5 7.0

4054 G09

CHRG Pin I-V Curve (Strong Pull-Down State)

25

20

15

(mA)

CHRG

10

I

5

0

2

1

4

V

3

CHRG

4

(V)

VCC = 5V V

BAT

T

A

5

= 4V

= 25°C

6

4054 G10

CHRG Pin Current vs Temperature (Strong Pull-Down State)

20

VCC = 5V

= 4V

V

18

BAT

= 1V

V

CHRG

16

14

(mA)

12

CHRG

I

10

8

6

7

4

–50

050

–25 25 75 125

TEMPERATURE (°C)

100

4054 G11

CHRG Pin I-V Curve (Weak Pull-Down State)

22

20

18

16

(µA)

14

CHRG

I

12

10

8

0

12

V

VCC = 5V

= 4.3V

V

BAT

= 25°C

T

A

467

35

(V)

CHRG

4054 G12

405442xf

LTC4054-4.2/LTC4054X-4.2

UW

TYPICAL PERFOR A CE CHARACTERISTICS

CHRG Pin Current vs Temperature (Weak Pull-Down State)

28

VCC = 5V

= 4.3V

V

BAT

(µA)

CHRG

I

25

23

19

16

13

10

–50

V

CHRG

= 5V

–25

02550

TEMPERATURE (°C)

Trickle Charge Threshold vs Temperature

3.000 VCC = 5V

= 10k

R

2.975

PROG

2.950

2.925

(V)

2.900

TRIKL

V

2.875

2.850

2.825

2.800

–50

0 25 50 75 100

–25

TEMPERATURE (°C)

75 100

4054 G13

4054 G16

Trickle Charge Current vs Temperature

50

R

= 2k

PROG

40

30

(mA)

TRIKL

20

I

10

0

–50

R

PROG

0 25 50 75 100

–25

TEMPERATURE (°C)

= 10k

VCC = 5V V

Charge Current vs Battery Voltage

600

500

400

(mA)

300

BAT

I

200

100

0

2.7 3.0

TA = 0°C

3.3 3.93.6

TA = 40°C

TA = 25°C

VCC = 5V

= 125°C/W

θ

JA

R

PROG

V

(V)

BAT

= 2k

BAT

= 2.5V

4054 G14

4.2

4054 G17

4.5

Trickle Charge Current vs Supply Voltage

50

R

= 2k

PROG

40

30

(mA)

TRIKL

20

I

10

0

4.5 5.0 5.5 6.0

4.0

R

PROG

= 10k

VCC (V)

Charge Current vs Supply Voltage

600

R

= 2k

500

400

(mA)

300

BAT

I

200

100

V

= 4V

BAT

= 25°C

T

A

= 80°C/W

θ

JA

0

4.0

4.5

PROG

R

= 10k

PROG

5.0 5.5 6.0 VCC (V)

ONSET OF THERMAL REGULATION

V

BAT

T

A

= 25°C

= 2.5V

6.5 7.0

4054 G15

6.5 7.0

4054 G18

Charge Current vs Ambient Temperature

600

R

= 2k

= 4V

BAT

= 80°C/W

JA

–25 0

PROG

REGULATION

R

= 10k

PROG

TEMPERATURE (°C)

500

400

VCC = 5V

(mA)

V

300

θ

BAT

I

200

100

0

–50 25 75

ONSET OF THERMAL

50 100 125

4054 G19

Recharge Voltage Threshold vs Temperature

4.11 VCC = 5V

= 10k

R

PROG

4.09

4.07

(V)

4.05

RECHRG

V

4.03

4.01

3.99

–50 25 75

–25 0

TEMPERATURE (°C)

50 100

4054 G20

Power FET “ON” Resistance vs Temperature

700

VCC = 4.2V

= 100mA

I

BAT

650

600

550

(mΩ)

500

DS(ON)

R

450

400

350

= 2k

R

PROG

–50 25 75

–25 0

TEMPERATURE (°C)

50 100 125

4054 G21

405442xf

5

LTC4054-4.2/LTC4054X-4.2

U

UU

PI FU CTIO S

CHRG (Pin 1): Open-Drain Charge Status Output. When the battery is charging, the CHRG pin is pulled low by an internal N-channel MOSFET. When the charge cycle is completed, a weak pull-down of approximately 20µA is connected to the CHRG pin, indicating an “AC present” condition. When the LTC4054 detects an undervoltage lockout condition, CHRG is forced high impedance.

GND (Pin 2): Ground. BAT (Pin 3): Charge Current Output. Provides charge

current to the battery and regulates the final float voltage to 4.2V. An internal precision resistor divider from this pin sets the float voltage which is disconnected in shutdown mode.

VCC (Pin 4): Positive Input Supply Voltage. Provides power to the charger. VCC can range from 4.25V to 6.5V and should be bypassed with at least a 1µF capacitor. When VCC drops to within 30mV of the BAT pin voltage, the LTC4054 enters shutdown mode, dropping I than 2µA.

BAT

to less

PROG (Pin 5): Charge Current Program, Charge Current Monitor and Shutdown Pin. The charge current is programmed by connecting a 1% resistor, R When charging in constant-current mode, this pin servos to 1V. In all modes, the voltage on this pin can be used to measure the charge current using the following formula:

I

= (V

BAT

The PROG pin can also be used to shut down the charger. Disconnecting the program resistor from ground allows a 3µA current to pull the PROG pin high. When it reaches the 1.21V shutdown threshold voltage, the charger enters shutdown mode, charging stops and the input supply current drops to 25µA. This pin is also clamped to approximately 2.4V. Driving this pin to voltages beyond the clamp voltage will draw currents as high as 1.5mA. Reconnecting R normal operation.

PROG/RPROG

PROG

) • 1000

to ground will return the charger to

, to ground.

PROG

6

405442xf

Linear LTC4054ES5-4.2, LTC4054XES5-4.2 Schematic [ru]