FEATURES
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LTC4069
Standalone 750mA Li-Ion
Battery Charger in 2
×
2 DFN
with NTC Thermistor Input
DESCRIPTION
The LTC
®
4069 is a complete constant-current/constant-
voltage linear charger for single-cell lithium-ion batteries.
The 2mm
×
2mm DFN package and low external component
count make the LTC4069 especially well-suited for portable
applications. Furthermore, LTC4069 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
manufacturer specifications.
No external sense resistor or blocking diode is required
due to the internal MOSFET architecture. Thermal feedback
regulates charge current to limit the die temperature
during high power operation or high ambient temperature
conditions.
When the input supply (wall adapter or USB supply) is
removed, the LTC4069 automatically enters a low current
state, dropping battery drain current to less than 1μA. With
power applied, LTC4069 can be put into shutdown mode,
reducing the supply current to less than 20μA.
The LTC4069 also includes automatic recharge, low-battery
charge conditioning (trickle charging), soft-start (to limit
inrush current) and an NTC thermistor input used to
monitor battery temperature.
The LTC4069 is available in a tiny 6-lead, low profile
(0.75mm) 2mm
×
2mm DFN package.
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Complete Linear Charger in 2mm
×
2mm DFN
Package
C/10 Charge Current Detection Output
Timer Charge Termination
Charge Current Programmable up to 750mA with
5% Accuracy
No External MOSFET, Sense Resistor or Blocking
Diode Required
NTC Thermistor Input for Temperature Qualified
Charging
Preset 4.2V Float Voltage with 0.6% Accuracy
Constant-Current/Constant-Voltage Operation with
Thermal Feedback to Maximize Charge 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
Soft-Start Limits Inrush Current
Tiny 6-Lead (2mm
×
2mm) DFN Package
APPLICATIONS
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Wireless PDAs
Cellular Phones
Portable Electronics
, LT, LTC and LTM 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
500mA
V
IN
4.3V TO 5.5V
R
NOM
100k
V
CC
R1
510Ω
BAT
Complete Charge Cycle (1000mAh Battery)
600
500
CHARGE CURRENT (mA)
400
300
200
100
4069 TA01
4.50
CONSTANT
CURRENT
CONSTANT
VOLTAGE
4.25
BATTREY VOLTAGE (V)
4.00
3.75
3.50
3.25
V
CC
= 5V
R
PROG
= 2k
0 0.5 1
1.5
2 2.5 3 3.5 4
TIME (HOURS)
4.5
5
4069 TA01b
LTC4069
CHRG PROG
NTC
GND
R
PROG
2k
CHRG
TRANSITION
+
4.2V
Li-Ion
BATTERY
R
NTC
100k
1μF
CHARGE
TERMINATION
0
3.00
4069fb
1
LTC4069
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
GND 1
CHRG
2
BAT 3
7
6 PROG
5 NTC
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
PROG, NTC ..................................... –0.3V to V
CC
+ 0.3V
BAT Short-Circuit Duration............................Continuous
BAT Pin Current .................................................. 800mA
PROG Pin Current ................................................ 800μA
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
LTC4069EDC#PBF
TAPE AND REEL
LTC4069EDC#TRPBF
PART MARKING
LBZX
PACKAGE DESCRIPTION
6-Lead (2mm X 2mm) Plastic DFN
TEMPERATURE RANGE
–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/
ELECTRICAL CHARACTERISTICS
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
NTC
= 0V unless otherwise specified. (Note 2)
SYMBOL
V
CC
I
CC
I
CCMS
I
CCUV
V
FLOAT
I
BAT
I
BMS
I
BUV
V
UVLO
V
PROG
V
ASD
PARAMETER
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
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
CONDITIONS
(Note 4)
V
BAT
= 4.5V (Forces I
BAT
and I
PROG
= 0)
Float PROG
V
CC
< V
BAT
, V
CC
= 3.5V, V
BAT
= 4V
I
BAT
= 2mA
I
BAT
= 2mA, 0°C < T
A
< 85°C
R
PROG
= 10k (0.1%), Current Mode
R
PROG
= 2k (0.1%), Current Mode
Floating PROG, V
CC
> V
BAT
V
CC
= 3.5V, V
BAT
= 4V
V
CC
Rising
V
CC
Falling
R
PROG
= 2k, I
PROG
= 500μA
R
PROG
= 10k, I
PROG
= 100μA
(V
CC
– V
BAT
), V
CC
Low to High
(V
CC
– V
BAT
), V
CC
High to Low
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MIN
3.75
TYP
120
20
6
MAX
5.5
250
40
11
4.225
4.242
112
525
1
4
3.8
3.2
1.02
1.02
100
45
UNITS
V
μA
μA
μA
V
V
mA
mA
μA
μA
V
V
V
V
mV
mV
4069fb
4.375
4.358
88
475
–1
0
3.4
2.8
0.98
0.98
60
15
4.2
4.2
100
500
0
1
3.6
3
1
1
80
30
2
LTC4069
ELECTRICAL CHARACTERISTICS
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
NTC
= 0V unless otherwise specified. (Note 2)
SYMBOL
I
PROG
V
MS, PROG
t
SS
I
TRKL
V
TRKL
V
TRHYS
ΔV
RECHRG
ΔV
UVCL1
ΔV
UVCL2
t
TIMER
PARAMETER
PROG Pin Pull-Up Current
PROG Shutdown Threshold Voltage
Soft-Start Time
Trickle Charge Current
Trickle Charge Threshold Voltage
Trickle Charge Hysteresis Voltage
Recharge Battery Threshold Voltage
(V
CC
– V
BAT
) Undervoltage Current
Limit
Termination Timer
Recharge Timer
Low-Battery Trickle Charge Time
V
CHRG
I
CHRG
I
C/10
T
LIM
R
ON
f
BADBAT
D
BADBAT
I
NTC
V
COLD
V
HOT
V
NTC-DIS
V
DIS-HYS
f
NTC
D
NTC
CHRG
Pin Output Low Voltage
CHRG
Pin Leakage 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
NTC Pin Current
Cold Temperature Fault Threshold
Voltage
Hot Temperature Fault Threshold
Voltage
NTC Disable Threshold Voltage
NTC Disable Hysteresis Voltage
Fault Temperature
CHRG
Pulse Frequency
Fault Temperature
CHRG
Pulse Frequency
Duty Ratio
V
NTC
= 2.5V
Rising Voltage Threshold
Hysteresis
Falling Voltage Threshold
Hysteresis
Falling Threshold; V
CC
= 5V
0.76 • V
CC
0.015 • V
CC
0.35 • V
CC
0.017 • V
CC
82
50
2
25
I
BAT
= 350mA
V
BAT
= 2.5V
I
CHRG
= 5mA
V
BAT
= 4.5V, V
CHRG
= 5V
R
PROG
= 2k (Note 5)
V
FLOAT
– V
RECHRG
, 0°C < T
A
< 85°C
I
BAT
= 90% Programmed Charge Current
I
BAT
= 10% Programmed Charge Current
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l
l
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CONDITIONS
V
PROG
> 1V
V
PROG
Rising
V
BAT
= 2V, R
PROG
= 2k (0.1%)
V
BAT
Rising
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MIN
3.7
35
2.7
70
180
90
3
1.5
0.75
TYP
3
4
170
50
2.9
90
100
220
125
4.5
2.25
1.125
60
0
MAX
4.3
65
3.05
130
330
150
6
3
1.5
105
1
0.11
UNITS
μA
V
μs
mA
V
mV
mV
mV
mV
Hrs
Hrs
Hrs
mV
μA
mA/mA
°C
mΩ
Hz
%
0.08
0.095
115
450
2
75
1
μA
V
V
V
V
mV
mV
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 LTC4069 is guaranteed to meet performance specifications
from 0°C to 85°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 LTC4069 functions properly at 3.75V, full charge
current requires an input voltage greater than the desired final battery
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.
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LTC4069
TYPICAL PERFORMANCE CHARACTERISTICS
Battery Regulation (Float) Voltage
vs Battery Charge Current
4.24
4.23
4.22
V
FLOAT
(V)
V
FLOAT
(V)
4.21
4.20
4.19
4.18
4.17
4.16
0
100
200
300
I
BAT
(mA)
400
500
4069 G01
Battery Regulation (Float) Voltage
vs Temperature
4.24
4.23
4.22
V
FLOAT
(V)
4.21
4.20
4.19
4.18
4.17
4.16
–50
–25
50
25
TEMPERATURE (°C)
0
75
100
4069 G02
Battery Regulation (Float) Voltage
vs Supply Voltage
4.24
4.23
4.22
4.21
4.20
4.19
4.18
4.17
4.16
4
5
4.5
5.5
SUPPLY VOLTAGE (V)
6
4069 G03
V
CC
= 5V
T
A
= 25°C
R
PROG
= 2k
T
A
= 25°C
I
BAT
= 2mA
R
PROG
= 2k
Charge Current vs Supply Voltage
(Constant-Current Mode)
200
175
150
I
BAT
(mA)
I
BAT
(mA)
R
PROG
= 10k
V
BAT
= 3.8V
T
A
= 25°C
600
500
400
Charge Current vs Battery Voltage
V
CC
= 5V
T
A
= 25°C
R
PROG
= 2k
600
500
400
I
BAT
(mA)
300
200
100
Charge Current vs Ambient
Temperature with Thermal
Regulation (Constant-Current Mode)
125
100
75
50
25
0
4
4.5
5
5.5
SUPPLY VOLTAGE (V)
6
4069 G04
THERMAL CONTROL
LOOP IN OPERATION
300
200
100
0
0
1
2
3
V
BAT
(V)
4
5
4069 G05
0
–50
V
CC
= 5V
V
BAT
= 3.8V
R
PROG
= 2k
0
100
50
TEMPERATURE (°C)
150
4069 G06
PROG Pin Voltage vs Temperature
(Constant-Current Mode)
1.02
V
CC
= 5V
V
BAT
= 3.8V
R
PROG
= 10k
1.2
1.0
0.8
V
PROG
(V)
V
PROG
(V)
PROG Pin Voltage
vs Charge Current
V
CC
= 5V
T
A
= 25°C
R
PROG
= 2k
550
Power FET On-Resistance
vs Temperature
V
CC
= 4V
I
BAT
= 400mA
1.01
R
DS
(mΩ)
500
4069 G08
500
450
1.00
0.6
0.4
400
0.99
0.2
0.98
–50
0
0
100
200
300
I
BAT
(mA)
400
350
–25
50
25
0
TEMPERATURE (°C)
75
100
4069 G07
300
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4069 G09
4069fb
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LTC4069
TYPICAL PERFORMANCE CHARACTERISTICS
Undervoltage Lockout Threshold
Voltage vs Temperature
4.00
3.75
RISE
3.50
I
BAT
(mA)
V
CC
(V)
3.25
3.00
2.75
2.50
–50
FALL
40
30
20
10
0
–25
50
0
25
TEMPERATURE (°C)
75
100
4069 G16
Trickle Charge Current
vs Supply Voltage
60
50
V
BAT
= 2V
T
A
= 25°C
R
PROG
= 2k
60
50
40
I
BAT
(mA)
30
20
R
PROG
= 10k
10
Trickle Charge Current
vs Temperature
V
CC
= 5V
V
BAT
= 2V
R
PROG
= 2k
R
PROG
= 10k
4
4.5
5
5.5
SUPPLY VOLTAGE (V)
6
4069 G14
0
–50
–25
50
25
0
TEMPERATURE (°C)
75
100
4069 G15
CHRG
Pin Output Low Voltage
vs Temperature
140
120
100
V
CHRG
(mV)
80
60
40
20
0
–50
V
CC
= 5V
I
CHRG
= 5mA
TIMER ACCURACY (%)
1
0
Timer Accuracy vs Temperature
V
CC
= 5V
2.0
1.5
TIMER ACCURACY (%)
1.0
0.5
0
–0.5
–1.0
–1.5
–25
50
25
TEMPERATURE (°C)
0
75
100
4069 G18
Timer Accuracy vs Supply Voltage
T
A
= 25°C
–1
–2
–3
–4
–5
–6
–25
50
25
0
TEMPERATURE (°C)
75
100
4069 G10
–7
–50
–2.0
4
5
4.5
5.5
SUPPLY VOLTAGE (V)
6
4069 G19
PROG Pin Shutdown Voltage
Threshold vs Temperature
5.0
V
CC
= 5V
5.0
4.5
4.5
V
MS(PROG)
(V)
V
MS(PROG)
(V)
PROG Pin Shutdown Voltage
vs Supply Voltage
T
A
= 25°C
4.0
3.5
3.0
2.5
4.0
3.5
3.0
–50
2.0
–25
0
25
50
TEMPERATURE (°C)
75
100
4069 G20
4
4.5
5
5.5
SUPPLY VOLTAGE (V)
6
4069 G21
4069fb
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