FEATURES
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LTC4065L/
LTC4065LX/LTC4065L-4.1
Standalone 250mA Li-Ion
Battery Charger in 2
×
2 DFN
DESCRIPTION
The LTC
®
4065L is a complete constant-current/constant-
voltage linear charger for single-cell lithium-ion batteries.
Its small size and ability to accurately regulate low charge
currents make the LTC4065L especially well-suited for
portable applications using low capacity rechargeable
lithium-ion cells. Furthermore, LTC4065L is specifically
designed to work within USB power specifications.
The
CHRG
pin indicates when charge current has dropped
to ten percent of its programmed value (C/10). An internal
timer terminates charging according to battery manufac-
turer specifications.
The LTC4065L-4.1 features a constant-voltage float voltage
of 4.1V. This 4.1V version of the standard LTC4065L is in-
tended for back-up or high ambient temperature applications.
Under these conditions, a reduced float voltage will trade-
off initial cell capacity for the benefit of increased capacity
retention over the life of the battery. A reduced float voltage
also minimizes swelling in prismatic and polymer cells.
When the input supply (wall adapter or USB supply) is
removed, the LTC4065L automatically enters a low current
state, dropping battery drain current to less than 1μA. With
power applied, LTC4065L can be put into shutdown mode,
reducing the supply current to less than 20μA.
The full-featured LTC4065L also includes automatic re-
charge, low-battery charge conditioning (trickle charging)
and soft-start (to limit inrush current).
Complete Charge Cycle (180mAh Battery)
LTC4065L and LTC4065LX
110
100
100mA
V
CC
BAT
CHARGE CURRENT (mA)
4.3
CONSTANT
VOLTAGE
CHRG
TRANSITION
4.1
3.9
3.7
CHARGE
TERMINATION
V
CC
= 5V
R
PROG
= 2k
0
0.5
1
1.5 2 2.5 3
TIME (HOURS)
3.5
4
4.5
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Charge Current Programmable up to 250mA with
5% Accuracy
Complete Linear Charger in 2mm
×
2mm DFN Package
C/10 Charge Current Detection Output
Timer Termination
No External MOSFET, Sense Resistor or Blocking
Diode Required
Preset Float Voltage with 0.6% Accuracy:
4.2V for LTC4065L/LTC4065LX
4.1V for LTC4065L-4.1
Constant-Current/Constant-Voltage Operation with
Thermal Feedback to Maximize Charging Rate
Without Risk of Overheating
Charge Current Monitor Output for Gas Gauging
Automatic Recharge
Charges Single Cell Li-Ion Batteries Directly from
USB Port
20μA Supply Current in Shutdown Mode
Available Without Trickle Charge (LTC4065LX)
Tiny 6-Lead (2mm
×
2mm) DFN Package
APPLICATIONS
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Charger for Li-Ion Coin Cell Batteries
Portable MP3 Players, Wireless Headsets
Bluetooth Applications
Multifunction Wristwatches
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 6522118, 6700364.
TYPICAL APPLICATION
Standalone Li-Ion Battery Charger
V
IN
4.3V TO 5.5V
C1
1μF
90 CONSTANT
CURRENT
80
70
60
50
40
30
20
10
0
BATTERY VOLTAGE (V)
R1
510Ω
LTC4065L
CHRG
PROG
EN
GND
R3
2k
+
4.2V
Li-Ion
BATTERY
4065L TA01
3.5
3.3
4065 TA02
1
LTC4065L/
LTC4065LX/LTC4065L-4.1
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
GND 1
CHRG
2
BAT 3
7
6 PROG
5
EN
4 V
CC
V
CC
t < 1ms and Duty Cycle < 1% ..................– 0.3V to 7V
Steady State............................................. –0.3V to 6V
BAT,
CHRG
................................................... –0.3V to 6V
EN,
PROG.........................................–0.3V to V
CC
+ 0.3V
BAT Short-Circuit Duration............................Continuous
BAT Pin Current ...................................................275mA
PROG Pin Current .............................................1.342mA
Junction Temperature (Note 6) ............................. 125°C
Operating Temperature Range (Note 2)....– 40°C to 85°C
Storage Temperature Range................... –65°C to 125°C
DC PACKAGE
6-LEAD (2mm
×
2mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 60°C/W (NOTE 3)
EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LTC4065LEDC#PBF
LTC4065LXEDC#PBF
LTC4065LEDC-4.1#PBF
TAPE AND REEL
LTC4065LEDC#TRPBF
LTC4065LXEDC#TRPBF
LTC4065LEDC-4.1#TRPBF
PART MARKING
LCBD
LCKS
LGGN
PACKAGE DESCRIPTION
6-Lead (2mm
×
2mm) Plastic DFN
6-Lead (2mm
×
2mm) Plastic DFN
6-Lead (2mm
×
2mm) Plastic DFN
TEMPERATURE RANGE
–40°C to 85°C
–40°C to 85°C
–40°C to 85°C
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/
LTC4065 Options
PART NUMBER
LTC4065
LTC4065A
LTC4065-4.4
LTC4065L
LTC4065LX
LTC4065L-4.1
FLOAT VOLTAGE
4.2V
4.2V
4.4V
4.2V
4.2V
4.1V
CHARGE CURRENT RANGE
40mA TO 750mA
40mA TO 750mA
40mA TO 750mA
8mA TO 250mA
8mA TO 250mA
8mA TO 250mA
PIN 5 IS
EN
OR
ACPR?
EN
ACPR
EN
EN
EN
EN
TRICKLE CHARGE?
YES
YES
YES
YES
NO
YES
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LTC4065L/
LTC4065LX/LTC4065L-4.1
The
l
denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C. V
CC
= 5V, V
BAT
= 3.8V, V
EN
= 0V unless otherwise specified. (Note 2)
SYMBOL PARAMETER
V
CC
I
CC
I
CCMS
I
CCUV
V
FLOAT
V
CC
Supply Voltage
Quiescent V
CC
Supply Current
V
CC
Supply Current in Shutdown
V
CC
Supply Current in Undervoltage
Lockout
V
BAT
Regulated Output Voltage
CONDITIONS
(Note 4)
V
BAT
= 4.5V (Forces I
BAT
and I
PROG
= 0)
V
EN
= 5V
V
CC
< V
BAT
, V
CC
= 3.5V, V
BAT
= 4V
I
BAT
= 2mA
I
BAT
= 2mA, 0°C < T
A
< 85°C
I
BAT
= 2mA (LTC4065L-4.1)
I
BAT
= 2mA, 0°C < T
A
< 85°C (LTC4065L-4.1)
R
PROG
= 13.3k (0.1%), Current Mode
R
PROG
= 1.33k (0.1%), Current Mode
V
EN
= V
CC
V
CC
= 3.5V, V
BAT
= 4V
V
CC
Rising
V
CC
Falling
R
PROG
= 1.33k, I
PROG
= 0.75mA
R
PROG
= 13.3k, I
PROG
= 75μA
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ELECTRICAL CHARACTERISTICS
MIN
3.75
TYP
120
20
6
MAX
5.5
250
40
11
4.225
4.242
4.125
4.142
17.5
162
1
4
3.8
3.2
1.02
1.02
100
45
1
UNITS
V
μA
μA
μA
V
V
V
V
mA
mA
μA
μA
V
V
V
V
mV
mV
V
V
MΩ
μs
mA
V
mV
mV
mV
mV
Hrs
Hrs
Hrs
mV
4.175
4.158
4.075
4.058
13.5
148
–1
0
3.4
2.8
0.98
0.98
60
15
0.6
l
4.2
4.2
4.1
4.1
15.5
155
0
1
3.6
3.0
1
1
80
30
I
BAT
I
BMS
I
BUV
V
UVLO
V
PROG
V
ASD
V
MSH
V
MSL
R
EN
t
SS
I
TRKL
V
TRKL
V
TRHYS
ΔV
UVCL1
ΔV
UVCL2
t
TIMER
BAT Pin Current
Battery Drain Current in Shutdown
Mode
Battery Drain Current in Undervoltage
Lockout
V
CC
Undervoltage Lockout Voltage
PROG Pin Voltage
Automatic Shutdown Threshold Voltage (V
CC
– V
BAT
), V
CC
Low to High
(V
CC
– V
BAT
), V
CC
High to Low
Manual Shutdown High Voltage
Manual Shutdown Low Voltage
EN
Pin Input Resistance
Soft-Start Time
Trickle Charge Current
Trickle Charge Threshold Voltage
Trickle Charge Hysteresis Voltage
(V
CC
– V
BAT
) Undervoltage Current
Limit
Termination Timer
Recharge Time
Low-Battery Trickle Charge Time
V
BAT
= 2.5V
I
CHRG
= 5mA
V
BAT
= 2V, R
PROG
= 1.33k (0.1%) (Note 7)
V
BAT
Rising (Note 7)
(Note 7)
V
FLOAT
– V
RECHRG
, 0°C < T
A
< 85°C
I
BAT
= 90%, R
PROG
= 2k, Programmed Charge Current
I
BAT
= 10%, R
PROG
= 2k, Programmed Charge Current
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V
EN
Rising
V
EN
Falling
0.9
13
2.7
70
150
80
3
1.5
0.75
1.5
170
15.5
2.9
90
100
190
125
4.5
2.25
1.125
60
3.3
18
3.05
130
300
150
6
3
1.5
105
ΔV
RECHRG
Recharge Battery Threshold Voltage
V
CHRG
CHRG
Pin Output Low Voltage
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LTC4065L/
LTC4065LX/LTC4065L-4.1
The
l
denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C. V
CC
= 5V, V
BAT
= 3.8V, V
EN
= 0V unless otherwise specified. (Note 2)
SYMBOL PARAMETER
I
CHRG
I
C/10
T
LIM
R
ON
f
BADBAT
D
BADBAT
CHRG
Pin Input Current
End of Charge Indication Current Level
Junction Temperature in Constant
Temperature Mode
Power FET “ON” Resistance
(Between V
CC
and BAT)
Defective Battery Detection
CHRG
Pulse Frequency
Defective Battery Detection
CHRG
Pulse Frequency Duty Ratio
I
BAT
= 150mA
CONDITIONS
V
BAT
= 4.5V, V
CHRG
= 5V
R
PROG
= 1.33k (Note 5)
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l
ELECTRICAL CHARACTERISTICS
MIN
0.08
TYP
0
0.095
115
1.5
2
75
MAX
1
0.11
UNITS
μA
mA/mA
°C
Ω
Hz
%
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:
The LTC4065L is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC4065L is guaranteed to meet performance specifica-
tions 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 3:
Failure to solder the exposed backside of the package to the PC
board ground plane will result in a thermal resistance much higher than
rated.
Note 4:
Although the LTC4065L functions properly at 3.75V input, full
charge current requires an input voltage greater than the desired final bat-
tery voltage per the ΔV
UVCL1
specification.
Note 5:
I
C/10
is expressed as a fraction of measured full charge current
with indicated PROG resistor.
Note 6:
This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 7:
This parameter is not applicable to the LTC4065LX.
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LTC4065L/
LTC4065LX/LTC4065L-4.1
TYPICAL PERFORMANCE CHARACTERISTICS
Battery Regulation (Float) Voltage
vs Battery Charge Current
4.24 V = 5V
CC
T
A
= 25°C
4.22
R
PROG
= 800Ω
4.20
LTC4065L
4.18
V
FLOAT
(V)
V
FLOAT
(V)
4.16
4.14
4.12
4.10
4.08
4.06
0
50
100
150
I
BAT
(mA)
200
250
4065L G01
Battery Regulation (Float) Voltage
vs Temperature
4.24
4.22
4.20
4.18
4.16
4.14
4.12
4.10
LTC4065L
4.18
V
FLOAT
(V)
4.16
4.14
4.12
4.10
LTC4065L-4.1
4.08
– 25
50
25
TEMPERATURE (°C)
0
75
100
4065L G02
Battery Regulation (Float) Voltage
vs Supply Voltage
4.24
4.22
4.20
T
A
= 25°C
I
BAT
= 2mA
R
PROG
= 800Ω
LTC4065L
LTC4065L-4.1
4.08
4.06
–50
LTC4065L-4.1
4.06
4
5
4.5
5.5
SUPPLY VOLTAGE (V)
6
4065L G03
Charge Current vs Supply Voltage
(Constant Current Mode)
30
25
20
I
BAT
(mA)
I
BAT
(mA)
15
10
5
0
4
4.5
5
5.5
SUPPLY VOLTAGE (V)
6
4065L G04
Charge Current vs Battery Voltage
300
250
200
I
BAT
(mA)
150
100
50
0
0
1
2
LTC4065L-4.1
3
V
BAT
(V)
4
5
4065L G05
Charge Current vs Temperature
with Thermal Regulation
(Constant Current Mode)
300
R
PROG
= 13.3k
V
BAT
= 3.8V
T
A
= 25°C
V
CC
= 5V
T
A
= 25°C
R
PROG
= 800Ω
LTC4065L
250
200
150
100
50
V
CC
= 5V
V
BAT
= 3.8V
R
PROG
= 800Ω
0
100
50
TEMPERATURE (°C)
150
4065L G06
THERMAL CONTROL
LOOP IN OPERATION
0
–50
PROG Pin Voltage vs Temperature
(Constant Current Mode)
1.02
V
CC
= 5V
V
BAT
= 3.8V
R
PROG
= 13.3k
1.2
1.0
0.8
V
PROG
(V)
V
PROG
(V)
1.00
0.6
0.4
0.99
0.2
0.98
–50
0
PROG Pin Voltage
vs Charge Current
V
CC
= 5V
T
A
= 25°C
R
PROG
= 800Ω
2.0
Power FET On Resistance
vs Temperature
V
CC
= 4V
I
BAT
= 150mA
1.01
R
DS
(Ω)
0
50
100
150
I
BAT
(mA)
200
250
4065L G08
1.8
1.6
1.4
1.2
–25
50
25
0
TEMPERATURE (°C)
75
100
4065L G07
1.0
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4065L G09
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