LTC4054-4.2/LTC4054X-4.2

405442i

Standalone Linear

Li-Ion Battery Charger with

Thermal Regulation in ThinSOT

February 2003

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

Programmable Charge Current Up to 800mA

No External MOSFET, Sense Resistor or Blocking
Diode Required

Complete Linear Charger in ThinSOT

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

A Supply Current in Shutdown

2.9V Trickle Charge Threshold (LTC4054)

Available Without Trickle Charge (LTC4054X)

Soft-Start Limits Inrush Current

Cellular Telephones, PDAs

Portable MP3 Players

Charging Docks and Cradles

Bluetooth Applications

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

ThinSOT is a trademark of Linear Technology Corporation.

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

Final Electrical Specifications

The LTC

4054 is a complete constant-current/constant-

voltage linear charger for single cell lithium-ion batteries.
Its ThinSOT package and low external component count
make the LTC4054 especially well-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. Ther-
mal 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 2

The LTC4054 can be put into shutdown mode, reducing
the supply current to 25

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

600mA Single Cell Li-Ion Charger

1.65k

4.2V
Li-Ion
BATTERY

405442 TA01a

LTC4054-4.2

4.5V TO 5.25V

BAT

PROG

GND

600mA

Complete Charge Cycle (750mAh Battery)

TIME (HOURS)

CHARGE CURRENT (mA)

1.5

405442 TAO1b

0.5

1.0

2.0

700

600

500

400

300

200

100

4.75

4.50

4.25

4.00

3.75

3.50

3.25

3.00

0.25

0.75

1.25

1.75

CONSTANT
POWER

CONSTANT

VOLTAGE

CONSTANT

CURRENT

CHARGE

TERMINATED

BATTERY VOLTAGE (V)

= 5V

= 130

C/W

PROG

= 1.65k

= 25

LTC4054-4.2/LTC4054X-4.2

405442i

(Note 1)

Input Supply Voltage (V

) ......................... 0.3 to 10V

PROG ............................................. 0.3V to V

+ 0.3V

BAT, CHRG ................................................. 0.3V to 7V
BAT Short-Circuit Duration .......................... Continuous
BAT Pin Current ................................................. 800mA
PROG Pin Current ................................................ 800

Maximum Junction Temperature .......................... 125

Operating Temperature Range (Note 2) .. 40

C to 85

Storage Temperature Range ................. 65

C to 125

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

JMAX

= 150

(

= 100

C/ W TO

150

C/W DEPENDING ON PC BOARD LAYOUT)

(N0TE 4)

ORDER PART

NUMBER

S5 PART MARKING

LTH7
LTADY

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Input Supply Voltage

4.25

6.5

Input Supply Current

Charge Mode (Note 3), R

PROG

= 2k

1200

2000

Standby Mode (Charge Terminated)

200

500

Shutdown Mode (R

PROG

Not Connected,

< V

BAT

, or V

< V

)

FLOAT

Regulated Output (Float) Voltage

C, I

BAT

= 40mA

4.158

4.2

4.242

BAT

BAT Pin Current

PROG

= 10k, Current Mode

100

107

PROG

= 2k, Current Mode

465

500

535

Standby Mode, V

BAT

= 4.2V

2.5

Shutdown Mode (R

PROG

Not Connected)

Sleep Mode, V

= 0V

TRIKL

Trickle Charge Current

BAT

< 2.9V, R

PROG

= 2k (Note 6)

TRIKL

Trickle Charge Threshold

PROG

= 2k, V

BAT

Rising (Note 6)

2.8

2.9

3.0

TRHYS

Trickle Charge Hysteresis

PROG

= 2k (Note 6)

110

Undervoltage Lockout Threshold

From V

Low to High

3.7

3.8

3.92

UVHYS

Undervoltage Lockout Hysteresis

150

250

300

MSD

Manual Shutdown Threshold

PROG Pin Rising

1.15

1.21

1.30

PROG Pin Falling

0.9

1.0

1.1

ASD

BAT

Lockout Threshold

from Low to High

100

140

from High to Low

TERM

C/10 Termination Current Threshold

PROG

= 10k (Note 5)

0.085

0.10

0.115

mA/mA

PROG

= 2k

0.085

0.10

0.115

mA/mA

PROG

PROG Pin Voltage

PROG

= 10k, Current Mode

0.93

1.0

1.07

CHRG

CHRG Pin Weak Pull-Down Current

CHRG

= 5V

CHRG

CHRG Pin Output Low Voltage

CHRG

= 5mA

0.35

0.6

RECHRG

Recharge Battery Threshold

FLOAT

- V

RECHRG

100

150

200

The

denotes specifications which apply over the full operating

temperature range, otherwise specifications are at T

= 25

C. V

= 5V, unless otherwise noted.

ABSOLUTE AXI U RATI GS

PACKAGE/ORDER I FOR ATIO

ELECTRICAL CHARACTERISTICS

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

CHRG 1

GND 2

TOP VIEW

S5 PACKAGE

5-LEAD PLASTIC TSOT-23

BAT 3

5 PROG

4 V

LTC4054ES5-4.2
LTC4054XES5-4.2

LTC4054-4.2/LTC4054X-4.2

405442i

PI FU CTIO S

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

C to 85

C operating temperature range are assured by design,

characterization and correlation with statistical process controls.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

LIM

Junction Temperature in Constant

120

Temperature Mode

Power FET "ON" Resistance

Current Mode

600

(Between V

and BAT)

Soft-Start Time

BAT

= 0 to I

BAT

=1000V/R

PROG

100

RECHARGE

Recharge Comparator Filter Time

BAT

High to Low

0.75

TERM

Termination Comparator Filter Time

BAT

Falling

400

1000

PROG

PROG Pin Pull-Up Current

The

denotes specifications which apply over the full operating

temperature range, otherwise specifications are at T

= 25

C. V

= 5V, unless otherwise noted.

ELECTRICAL CHARACTERISTICS

Note 3: Supply current includes PROG pin current but does not include
any current delivered to the battery through the BAT pin.

Note 4: See Thermal Considerations.

Note 5: I

TERM

is expressed as a fraction of measured full charge current

with indicated PROG resistor.

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

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 20

A is

connected to the CHRG pin, indicating an "AC present"
condition. When the LTC4054 detects an undervoltage
lockout condition, CHRG is forced to a high impedance
state.

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 and is disconnected in shutdown
mode.

(Pin 4): Positive Input Supply Voltage. Provides

power to the charger. V

can range from 4.25V to 6.5V

and should be bypassed with at least a 1

F capacitor.

When V

drops to within 30mV of the BAT pin voltage, the

LTC4054 enters shutdown mode, dropping I

BAT

to less

than 2

PROG (Pin 5): Charge Current Program, Charge Current
Monitor and Shutdown Pin. The charge current is pro-
grammed by connecting a 1% resistor, R

PROG

, to ground.

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:

BAT

= (V

PROG

) · 1000

The PROG pin can also be used to shut down the charger.
Disconnecting the program resistor from ground allows
a 3

A 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 25

A. 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

PROG

to ground will return the charger to

normal operation.

LTC4054-4.2/LTC4054X-4.2

405442i

OPERATIO

The LTC4054 is a single cell lithium-ion battery charger
using a constant-current/constant-voltage algorithm. It
can deliver up to 800mA of charge current (using a good
thermal PCB layout) with a final float voltage accuracy of

1%. The LTC4054 includes an internal P-channel power

MOSFET and thermal regulation circuitry. No blocking
diode or external current sense resistor is required; thus,
the basic charger circuit requires only three external com-
ponents. Furthermore, the LTC4054 is capable of operat-
ing from a USB power source.

Normal Charge Cycle

A charge cycle begins when the voltage at the V

pin rises

above the UVLO threshold level and a 1% program resistor
is connected from the PROG pin to ground. If the BAT pin
is less than 2.9V, the charger enters trickle charge mode.
In this mode, the LTC4054 supplies approximately 1/10
the programmed charge current to bring the battery volt-
age up to a safe level for full current charging. (Note: The
LTC4054X does not include this trickle charge feature).

When the BAT pin voltage rises above 2.9V, the charger
enters constant-current mode, where the programmed
charge current is supplied to the battery. When the BAT
pin approaches the final float voltage (4.2V), the LTC4054
enters constant-voltage mode and the charge current
begins to decrease. When the charge current drops to
1/10 of the programmed value, the charge cycle ends.

Programming Charge Current

The charge current is programmed using a single resistor
from the PROG pin to ground. The battery charge current
is 1000 times the current out of the PROG pin. The
program resistor and the charge current are calculated
using the following equations:

PROG

CHRG

PROG

1000

The charge current out of the BAT pin can be determined
at any time by monitoring the PROG pin voltage using the
following equation:

BAT

PROG

· 1000

Charge Termination

The charge cycle terminates when the charge current falls
to 1/10th the programmed current. An internal compara-
tor senses when the PROG pin voltage falls below 100mV

and puts the LTC4054 into standby mode. In standby
mode, the LTC4054 ceases to provide charge current to
the battery and the input supply current drops to 200

If the battery voltage drops below 4.05V, a recharge cycle
will begin. To manually restart the charge cycle, the input
voltage must be removed and reapplied, or the charger
must be shut down and restarted by momentarily floating
the PROG pin.

Charge Status Indicator (CHRG)

The charge status output has three different states: strong
pull-down (~10mA), weak pull-down (~20

A) and high

impedance. The strong pull-down state indicates that the
LTC4054 is in a charge cycle. Once the charge cycle has
terminated, the pin state is determined by undervoltage
lockout conditions. A weak pull-down indicates that V

meets the UVLO conditions and the LTC4054 is ready to
charge. High impedance indicates that the LTC4054 is in
undervoltage lockout mode: either V

is within 100mV of

the BAT pin voltage or insufficient voltage is applied to the
V

pin. A microprocessor can be used to distinguish

between these three states--this method is discussed in
the Applications Information section.

Note 1:

Any external sources that hold the PROG pin above 100mV will prevent the LTC4054

from terminating a charge cycle.

LTC4054-4.2/LTC4054X-4.2

405442i

OPERATIO

Thermal Limiting

An internal thermal feedback loop reduces the programmed
charge current if the die temperature attempts to rise
above a preset value of approximately 120

C. This feature

protects the LTC4054 from excessive temperature and
allows the user to push the limits of the power handling
capability of a given circuit board without risk of damaging
the LTC4054. The charge current can be set according to
typical (not worst-case) ambient temperature with the
assurance that the charger will automatically reduce the
current in worst-case conditions. ThinSOT power consid-
erations are discussed further in the Applications Informa-
tion section.

Undervoltage Lockout (UVLO)

An internal undervoltage lockout circuit monitors the input
voltage and keeps the charger in shutdown mode until V

rises above the undervoltage lockout threshold. The UVLO
circuit has a built-in hysteresis of 200mV. Furthermore, to
protect against reverse current in the power MOSFET, the
UVLO circuit keeps the charger in shutdown mode if V

falls to within 30mV of the battery voltage. If the UVLO
comparator is tripped, the charger will not come out of
shutdown mode until V

rises 100mV above the battery

voltage.

Manual Shutdown

At any point in the charge cycle, the LTC4054 can be put
into shutdown mode by removing R

PROG

thus floating the

PROG pin. This reduces the battery drain current to less
than 2

A and the supply current to less than 50

A. A new

charge cycle can be initiated by reconnecting the program
resistor.

Automatic Recharge

Once the charge cycle is terminated, the LTC4054 continu-
ously monitors the voltage on the BAT pin. A charge cycle
restarts when the battery voltage falls below 4.05V (which
corresponds to approximately 80% to 90% battery capac-
ity). This ensures that the battery is kept at or near a fully
charged conditon and eliminates the need for periodic
charge cycle initiations. CHRG output enters a strong pull-
down state during recharge cycles.

TRICKLE CHARGE

MODE

1/10TH FULL CURRENT

BAT > 2.9V

BAT < 2.9V

BAT > 2.9V

CHRG: STRONG

PULL-DOWN

CHARGE MODE

FULL CURRENT

CHRG: STRONG

PULL-DOWN

SHUTDOWN MODE

CHRG: Hi-Z IN UVLO

WEAK PULL-DOWN

OTHERWISE

PROG

RECONNECTED

UVLO CONDITION

STOPS

PROG FLOATED

UVLO CONDITION

DROPS TO <30

POWER ON

PROG < 100mV

STANDBY MODE

NO CHARGE CURRENT

CHRG: WEAK

PULL-DOWN

2.9V < BAT < 4.05V

405442 F01

Figure 1. State Diagram of a Typical Charge Cycle

LTC4054-4.2/LTC4054X-4.2

405442i

APPLICATIO S I FOR ATIO

Stability Considerations

The constant-voltage mode feedback loop is stable with-
out an output capacitor provided a battery is connected to
the charger output. With no battery present, an output
capacitor is recommended to reduce ripple voltage. When
using high value, low ESR ceramic capacitors, it is recom-
mended to add a 1

resistor in series with the capacitor.

No series resistor is needed if tantalum capacitors are
used.

In constant-current mode, the PROG pin is in the feedback
loop, not the battery. The constant-current mode stability
is affected by the impedance at the PROG pin. With no
additional capacitance on the PROG pin, the charger is
stable with program resistor values as high as 20k. How-
ever, additional capacitance on this node reduces the
maximum allowed program resistor. The pole frequency
at the PROG pin should be kept above 100kHz. Therefore,

PROG

10k

PROG

FILTER

405442 F02

CHARGE
CURRENT
MONITOR
CIRCUITRY

LTC4054

GND

Figure 2. Isolating Capacitive Load on PROG Pin and Filtering

if the PROG pin is loaded with a capacitance, C

PROG

, the

following equation can be used to calculate the maximum
resistance value for R

PROG

Average, rather than instantaneous, charge current may
be of interest to the user. For example, if a switching power
supply operating in low current mode is connected in
parallel with the battery, the average current being pulled
out of the BAT pin is typically of more interest than the
instantaneous current pulses. In such a case, a simple RC
filter can be used on the PROG pin to measure the average
battery current as shown in Figure 2. A 10k resistor has
been added between the PROG pin and the filter capacitor
to ensure stability.

LTC4054-4.2/LTC4054X-4.2

405442i

Power Dissipation

The conditions that cause the LTC4054 to reduce charge
current through thermal feedback can be approximated by
considering the power dissipated in the IC. Nearly all of
this power dissipation is generated by the internal
MOSFET--this is calculated to be approximately:

= (V

BAT

) · I

BAT

where P

is the power dissipated, V

is the input supply

voltage, V

BAT

is the battery voltage and I

BAT

is the charge

current. The approximate ambient temperature at which
the thermal feedback begins to protect the IC is:

= 120

C P

= 120

C (V

BAT

) · I

BAT

Example: An LTC4054 operating from a 5V USB supply is
programmed to supply 400mA full-scale current to a
discharged Li-Ion battery with a voltage of 3.75V. Assum-
ing

is 150

C/W (see Board Layout Considerations),

the ambient temperature at which the LTC4054 will begin
to reduce the charge current is approximately:

= 120

C (5V 3.75V) · (400mA) · 150

C/W

= 120

C 0.5W · 150

C/W = 120

C 75

= 45

The LTC4054 can be used above 45

C ambient, but the

charge current will be reduced from 400mA. The approxi-
mate current at a given ambient temperature can be
approximated by:

C T

BAT

(

)

120

Using the previous example with an ambient tempera-
ture of 60

C, the charge current will be reduced to

approximately:

C W

C A

BAT

(

)

120

3 75

150

187 5

320

APPLICATIO S I FOR ATIO

Moreover, when thermal feedback reduces the charge
current, the voltage at the PROG pin is also reduced
proportionally as discussed in the Operation section.

It is important to remember that LTC4054 applications do
not need to be designed for worst-case thermal conditions
since the IC will automatically reduce power dissipation
when the junction temperature reaches approximately
120

Thermal Considerations

Because of the small size of the ThinSOT package, it is very
important to use a good thermal PC board layout to
maximize the available charge current. The thermal path
for the heat generated by the IC is from the die to the
copper lead frame, through the package leads, (especially
the ground lead) to the PC board copper. The PC board
copper is the heat sink. The footprint copper pads should
be as wide as possible and expand out to larger copper
areas to spread and dissipate the heat to the surrounding
ambient. Feedthrough vias to inner or backside copper
layers are also useful in improving the overall thermal
performance of the charger. Other heat sources on the
board, not related to the charger, must also be considered
when designing a PC board layout because they will affect
overall temperature rise and the maximum charge current.

The following table lists thermal resistance for several
different board sizes and copper areas. All measurements
were taken in still air on 3/32" FR-4 board with one ounce
copper.

Table 1. Measured Thermal Resistance

COPPER AREA

BOARD

THERMAL RESISTANCE

TOPSIDE*

BACKSIDE

AREA

JUNCTION-TO-AMBIENT

2500mm

125

C/W

1000mm

2500mm

125

C/W

225mm

2500mm

130

C/W

100mm

2500mm

135

C/W

50mm

2500mm

150

C/W

*Device is mounted on topside

LTC4054-4.2/LTC4054X-4.2

405442i

APPLICATIO S I FOR ATIO

Increasing Thermal Regulation Current

Reducing the voltage drop across the internal MOSFET
can significantly decrease the power dissipation in the IC.
This has the effect of increasing the current delivered to
the battery during thermal regulation. One method is by
dissipating some of the power through an external compo-
nent, such as a resistor or diode.

Example: An LTC4054 operating from a 5V wall adapter is
programmed to supply 800mA full-scale current to a
discharged Li-Ion battery with a voltage of 3.75V. Assum-
ing

is 125

C/W, the approximate charge current at an

ambient temperature of 25

C is:

C W

BAT

120

3 75

125

608

(

)·

By dropping voltage across a resistor in series with a 5V
wall adapter (shown in Figure 3), the on-chip power
dissipation can be decreased, thus increasing the ther-
mally regulated charge current.

BAT

BAT CC

BAT

120

(

)·

PROG

Li-Ion
CELL

405442 F03

LTC4054-4.2

BAT

PROG

GND

Solving for I

BAT

using the quadratic formula

BAT

(

)

(

)

(

)

120

(

)

CHARGE CURRENT (mA)

1000

800

600

400

200

0.5

1.0

1.25

405442 F04

0.25

0.75

1.5

1.75

CONSTANT

CURRENT

BAT

= 3.75V

= 25

= 125

C/W

PROG

= 1.25k

THERMAL

MODE

DROPOUT

= 5.25V

= 5.5V

= 5V

Figure 4. Charge Current vs R

Using R

= 0.25

, V

= 5V, V

BAT

= 3.75V, T

= 25

C and

= 125

C/W we can calculate the thermally regulated

charge current to be:

BAT

= 708.4mA

While this application delivers more energy to the battery
and reduces charge time in thermal mode, it may actually
lengthen charge time in voltage mode if V

becomes low

enough to put the LTC4054 into dropout. Figure 4 shows
how this circuit can result in dropout as R

becomes

large.

This technique works best when R

values are minimized

to keep component size small and avoid dropout. Remem-
ber to choose a resistor with adequate power handling
capability.

Bypass Capacitor

Many types of capacitors can be used for input bypassing,
however, caution must be exercised when using multi-
layer ceramic capacitors. Because of the self-resonant and
high Q characteristics of some types of ceramic capaci-
tors, high voltage transients can be generated under some
start-up conditions, such as connecting the charger input
to a live power source. Adding a 1.5

resistor in series

with an X5R ceramic capacitor will minimize start-up
voltage transients. For more information, refer to Applica-
tion Note 88.

Note 2: Large values of R

will result in no solution for I

BAT

. This indicates that the LTC4054

will not generate enough heat to require thermal regulation.

Figure 3. A Circuit to Maximize Thermal Mode Charge Current

LTC4054-4.2/LTC4054X-4.2

405442i

CHRG

OUT

800k

405442 F05

LTC4054

PROCESSOR

Figure 5. Using a Microprocessor to Determine CHRG State

Charge Current Soft-Start

The LTC4054 includes a soft-start circuit to minimize the
inrush current at the start of a charge cycle. When a charge
cycle is initiated, the charge current ramps from zero to the
full-scale current over a period of approximately 100

This has the effect of minimizing the transient current load
on the power supply during start-up.

CHRG Status Output Pin

With no battery present, the CHRG pin can provide an
indication that the input voltage is present and it is greater
than the undervoltage lockout threshold level. A weak
pull-down current of approximately 20

A indicates that

sufficient voltage is applied to V

to begin charging.

When a discharged battery is connected to the charger, the
constant current portion of the charge cycle begins and
the CHRG pin pulls to ground. The CHRG pin can sink up
to 10mA to drive an LED that indicates that a charge cycle
is in progress.

When the battery is nearing full charge, the charger enters
the constant-voltage portion of the charge cycle and the
charge current begins to drop. When the charge current
drops below 1/10 of the programmed current, the charge
cycle ends and the strong pull-down is replaced by the
20

A pull-down, indicating that the charge cycle has

ended. If the input voltage is removed or drops below the
undervoltage lockout threshold, the CHRG pin becomes

high impedance. Figure 5 shows that by using two differ-
ent value pull-up resistors, a microprocessor can detect all
three states from this pin.

To detect when the LTC4054 is in charge mode, force the
digital output pin (OUT) high and measure the voltage at
the CHRG pin. The N-channel MOSFET will pull the pin
voltage low even with the 2k pull-up resistor. Once the
charge cycle terminates, the N-channel MOSFET is turned
off and a 20

A current source is connected to the CHRG

pin. The IN pin will then be pulled high by the 2k pull-up
resistor. To determine if there is a weak pull-down current,
the OUT pin should be forced to a high impedance state.
The weak current source will pull the IN pin low through
the 800k resistor; if CHRG is high impedance, the IN pin
will be pulled high, indicating that the part is in a UVLO
state.

APPLICATIO S I FOR ATIO

LTC4054-4.2/LTC4054X-4.2

405442i

PART NUMBER

DESCRIPTION

COMMENTS

LT1571

200kHz/500kHz Switching Battery Charger

Up to 1.5A Charge Current; Preset and Adjustable Battery Voltages

LTC1729

Lithium-Ion Battery Charger Termination Controllers Time or Charge Current Termination, Preconditioning 8-Lead MSOP

LTC1730

Lithium-Ion Battery Pulse Charger

No Blocking Diode Required, Current Limit for Maximum Safety

LTC1731

Lithium-Ion Linear Battery Charger Controller

Simple Charger uses External FET, Features Preset Voltages, C/10
Charger Detection and Programmable Timer

LTC1732

Lithium-Ion Linear Battery Charger Controller

Simple Charger uses External FET, Features Preset Voltages, C/10
Charger Detection and Programmable Timer, Input Power Good Indication

LTC1733

Monolithic Lithium-Ion Linear Battery Charger

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

LTC1734

Lithium-Ion Linear Battery Charger in ThinSOT

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

LTC1734L

Lithium-Ion Linear Battery Charger in ThinSOT

Accurate, Low Current Version of LTC1734

LTC1998

Lithium-Ion Low Battery Detector

1% Accurate 2.5

A Quiescent Current, SOT-23

LTC4050

Lithium-Ion Linear Battery Charger Controller

Simple Charger uses External FET, Features Preset Voltages, C/10
Charger Detection and Programmable Timer, Input Power Good Indication,
Thermistor Interface

LTC4052

Monolithic Lithium-Ion Battery Pulse Charger

No Blocking Diode or External Power FET Required

LTC4053

USB Compatible Monolithic Li-Ion Battery Charger

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

LTC4410

USB Power Manager

For Simultaneous Operation of USB Peripheral and Battery Charging from USB
Port, Keeps Current Drawn from USB Port Constant, Keeps Battery Fresh, Use
with the LTC4053, LTC1733, or LTC4054

LT/TP 0203 1.5K · PRINTED IN USA

LINEAR TECHNOLOGY CORPORATION 2003

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900

FAX: (408) 434-0507

www.linear.com

RELATED PARTS

TYPICAL APPLICATIO

800mA Li-Ion Charger with

External Power Dissipation

0.25

LTC4054-4.2

BAT

800mA

405442 TA03

PROG

1.25k

= 5V

GND

LTC4054-4.2

BAT

405442 TA04

PROG

5V WALL

ADAPTER

GND

500mA

Basic Li-Ion Battery Charger with
Reverse Polarity Input Protection

330

LTC4054-4.2

BAT

405442 TA02

PROG

= 5V

GND

CHRG

SHDN

500mA

Full Featured Single Cell

Li-Ion Charger

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: LTC4054ES5-4.2

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: LTC4054ES5-4.2