LINEAR TECHNOLOGY LTC1733 Technical data
Lithium-Ion Battery Charger with
FEATURES
■
Complete Linear Charger for 1-Cell Lithium-Ion
Batteries
■
Thermal Regulation Maximizes Charging Rate
without Risk of Overheating*
■
No External MOSFET, Sense Resistor or Blocking
Diode Required
■
Up to 1.5A Charge Current
■
Preset Charge Voltage with 1% Accuracy
■
Programmable Charge Current with 7% Accuracy
■
Programmable Charge Termination Timer
■
Tiny Thermally Enhanced 10-Pin MSOP Package
■
Charge Current Monitor Useful for Gas Gauging*
■
C/10 Charge Current Detection Output
■
Automatic Recharge
■
Thermistor Input for Temperature Qualified Charging
■
AC Present Logic Output
■
4.1V/4.2V Pin Selectable Output Voltage
U
APPLICATIO S
LTC1733
Monolithic Linear
Thermal Regulation
U
DESCRIPTIO
The LTC®1733 is a standalone constant-current/
constant-voltage linear charger for lithium-ion batteries
with an on-chip power MOSFET. Internal thermal feedback
regulates the charge current to limit die temperature
during high power operation or high ambient temperature
conditions. This feature allows the user to program a high
charge current without risk of damaging the LTC1733 or
the handheld product.
No external current sense resistor is needed and no
blocking diode is required due to the internal MOSFET
architecture. The charge current and charge time can be
set externally with a single resistor and capacitor, respectively. When the input supply (wall adapter) is removed,
the LTC1733 automatically enters a low current sleep
mode, dropping the battery drain current to less than 5µA.
The LTC1733 also includes NTC temperature sensing,
C/10 detection circuitry, AC present logic, 4.1V/4.2V pin
selectability and low battery charge conditioning (trickle
charging).
■
Cellular Telephones
■
Handheld Computers
■
Digital Still Cameras
■
Charging Docks and Cradles
TYPICAL APPLICATIO
Standalone Li-Ion Battery Charger
V
= 5V
IN
28
V
SEL
4.7µF
4
TIMER
GND
0.1µF
*AN OUTPUT CAPACITOR MAY BE REQUIRED
DEPENDING ON BATTERY LEAD LENGTH
LTC1733
5
CC
BAT
PROG
NTC
6
The LTC1733 is available in a 10-pin thermally enhanced
MSOP package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
*Patent Pending
U
Charge Current vs Battery Voltage
1200
1000
I
= 1A
BAT
9
1.5k
1%
1733TA01
4.2V
1-CELL
Li-Ion
BATTERY*
CHARGE CURRENT (mA)
7
800
600
400
200
TA = 0°C
TA = 25°C
CONSTANT
POWER
TRICKLE
0
2
CHARGE
VIN = 5V
= 40°C/W
θ
JA
2.5 3 4 4.5
BATTERY VOLTAGE (V)
CONSTANT
CURRENT
TA = 40°C
CONSTANT
VOLTAGE
3.5
1733 TA01b
sn1733 1733fs
1
LTC1733
WW
W
ABSOLUTE AXI U RATI GS
U
UUW
PACKAGE/ORDER I FOR ATIO
(Note 1)
Input Supply Voltage (VCC) ........................................ 7V
BAT............................................................................ 7V
NTC, SEL, TIMER, PROG ................ –0.3V to VCC + 0.3V
CHRG, FAULT, ACPR ...................................–0.3V to 7V
BAT Short-Circuit Duration ...........................Continuous
BAT Current (Note 2) .............................................. 1.6A
PROG Current (Note 2) ........................................ 1.6mA
Junction Temperature........................................... 125°C
TOP VIEW
1
CHRG
2
V
CC
FAULT
3
TIMER
4
GND
5
MSE EXPOSED PAD PACKAGE
10-LEAD PLASTIC MSOP
T
= 125°C, θJA = 40°C/W (Note 4)
JMAX
EXPOSED PAD IS GROUND.
(MUST BE SOLDERED TO PCB
FOR MAXIMUM HEAT TRANSFER).
10
ACPR
9
BAT
8
SEL
7
PROG
6
NTC
ORDER PART
NUMBER
LTC1733EMSE
MSE PART MARKING
LTLX
Operating Temperature Range (Note 3) ...–40°C to 85°C
Storage Temperature Range ................. –65°C to 150°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Lead Temperature (Soldering, 10 sec).................. 300°C
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifications are at TA = 25°C. VCC = 5V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
CC
I
CC
V
BAT
I
BAT
I
TRIKL
V
TRIKL
∆V
TRIKL
V
UV
∆V
UV
V
MSD
V
MSD-HYS
V
ASD
VCC Supply Voltage ● 4.5 6.5 V
VCC Supply Current Charger On; Current Mode; R
Shutdown Mode; V
V
Regulated Output Voltage SEL = 0V ● 4.059 4.1 4.141 V
BAT
Battery Pin Current R
Trickle Charge Current V
Trickle Charge Trip Threshold V
Trickle Charge Trip Hysteresis 100 mV
VCC Undervoltage Lockout Voltage VCC Rising ● 4.2 4.5 V
VCC Undervoltage Lockout Hysteresis 150 mV
Manual Shutdown Threshold Voltage PROG Pin Voltage Rising 2.15 V
Manual Shutdown Hysteresis Voltage 100 mV
Automatic Shutdown Threshold Voltage (VCC - V
SEL = V
R
Shutdown Mode; V
Sleep Mode V
(V
The ● denotes the specifications which apply over the full operating
= 30k (Note 5) ● 13 mA
PROG
= 3V ● 0.9 2 mA
PROG
CC
= 3k; Current Mode ● 465 500 535 mA
PROG
= 1k; Current Mode 1.395 1.5 1.605 A
PROG
CC
< 2V; R
BAT
BAT
CC
PROG
Rising 2.48 V
) Voltage Falling 30 mV
BAT
- V
) Voltage Rising 60 mV
BAT
= 3V ±1 ±5 µA
PROG
< V
or VCC < (VUV – ∆VUV) ±1 ±5 µA
BAT
= 3k ● 35 50 65 mA
● 4.158 4.2 4.242 V
2
sn1733 1733fs
LTC1733
ELECTRICAL CHARACTERISTICS
TA = 25°C. VCC = 5V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
PROG
I
CHRG
V
CHRG
V
ACPR
V
FAULT
I
C/10
t
TIMER
V
RECHRG
PROG Pin Voltage R
CHRG Pin Weak Pulldown Current V
CHRG Pin Output Low Voltage I
ACPR Pin Output Low Voltage I
FAULT Pin Output Low Voltage I
End of Charge Indication Current Level R
TIMER Accuracy C
= 3k, I
PROG
= 1V 25 µA
CHRG
= 5mA 0.35 V
CHRG
= 5mA 0.35 V
ACPR
= 5mA 0.35 V
FAULT
= 3k 35 50 65 mA
PROG
= 0.1µF ±10 %
TIMER
= 500µA; Current Mode 1.5 V
PROG
Recharge Battery Voltage Threshold Battery Voltage Falling, SEL = 0V 3.9 V
Battery Voltage Falling, SEL = 5V 4.0 V
V
NTC-HOT
V
HOT-HYS
V
NTC-COLD
V
COLD-HYS
V
NTC-DIS
V
DIS-HYS
V
SEL-IL
V
SEL-IH
T
LIM
NTC Pin Hot Threshold Voltage V
Falling 2.5 V
NTC
NTC Pin Hot Hysteresis Voltage 70 mV
NTC Pin Cold Threshold Voltage V
Rising 4.375 V
NTC
NTC Pin Cold Hystersis Voltage 70 mV
NTC Pin Disable Threshold Voltage V
Rising 100 mV
NTC
NTC Pin Disable Hystersis Voltage 10 mV
SEL Pin Threshold Input Low 0.3 V
SEL Pin Threshold Input High 1V
Junction Temperature in 105 °C
Constant-Temperature Mode
R
ON
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The Absolute Maximum BAT Current Rating of 1.6A is guaranteed
by design and current density calculations. The Absolute Maximum PROG
Current Rating is guaranteed to be 1/1000 of BAT current rating by design.
Note 3: The LTC1733E is guaranteed to meet performance specifications
Power MOSFET “ON” Resistance 375 mΩ
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 4: Failure to solder the exposed backside of the package to the PC
board will result in a thermal resistance much higher than 40°C/W.
Note 5: Supply current includes PROG pin current but does not include
any current delivered to the battery through the BAT pin.
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
sn1733 1733fs
3
LTC1733
VCC (V)
4.24
4.22
4.20
4.18
4.16
4.14
4.12
4.10
4.08
4.06
V
BAT
(V)
1733 G03
4.0 4.5 5.0
5.5
6.0 6.5 7.0
V
SEL
= V
CC
V
SEL
= 0V
TA = 25°C
I
BAT
= 10mA
R
PROG
= 1.5k
UW
TYPICAL PERFOR A CE CHARACTERISTICS
Battery Regulation Voltage vs
Battery Charge Current
4.24
4.22
V
= 5V
SEL
4.20
4.18
4.16
(V)
BAT
4.14
V
V
= 0V
SEL
4.12
4.10
4.08
4.06
0 100 200 300
400
500
I
(mA)
BAT
PROG Pin Voltage vs Charge
Current
1.6
VCC = 5V
= 25°C
T
A
1.4
R
= 1.5k
PROG
V
= 5V
SEL
1.2
1.0
(V)
0.8
PROG
V
0.6
0.4
0.2
0
0 100 200 300
400
500
CHARGE CURRENT (mA)
VCC = 5V
= 25°C
T
A
= 1.5k
R
PROG
600 700 800 900 1000
1733 G01
600 700 800 900 1000
1733 G04
Battery Regulation Voltage vs
Temperature
4.24
VCC = 5V
= 10mA
I
4.22
BAT
= 1.5k
R
PROG
4.20
4.18
4.16
(V)
BAT
4.14
V
4.12
4.10
4.08
4.06
–50 –25 0
25
50 75 100 125
TEMPERATURE(°C)
Charge Current vs Battery Voltage
1100
VCC = 5V
1000
= 25°C
T
A
= 1.5k
R
PROG
900
800
700
600
(mA)
500
BAT
I
400
300
200
100
V
0
0
= 5V
SEL
0.5 1.5
1.0
2.5 4.5
BAT
3.0
(V)
2.0
V
Battery Regulation Voltage vs V
V
= 5V
SEL
V
= 0V
SEL
1733 G02
CC
Charge Current vs Input Voltage
1100
1000
900
800
700
600
(mA)
500
BAT
I
400
3.5
4.0
1733 G05
300
200
100
0
4.0
4.5 5.5
5.0
VCC (V)
6.0
V
T
R
V
BAT
A
PROG
SEL
= 4.1V
= 25°C
= 5V
= 1.5k
6.5
1733 G06
7.0
Charge Current vs V
1100
1000
900
800
(mA)
700
BAT
I
600
500
400
4.0
4
R
PROG
R
PROG
4.5 5.5
5.0
VCC (V)
CC
= 1.5k
= 3k
6.0
V
BAT
T
A
V
SEL
= 3.5V
= 25°C
= V
6.5
1733 G07
Charge Current vs Temperature
with Thermal Regulation
1000
900
800
700
600
CC
7.0
500
(mA)
BAT
I
400
300
200
100
0
–50
VCC = 5V
= 3.5V
V
BAT
R
PROG
= 5V
V
SEL
THERMAL CONTROL
LOOP IN OPERATION
= 1.5k
–25 25
0
TEMPERATURE (°C)
75
50
100
1733 G08
Charge Current vs Temperature
535
530
525
520
515
510
505
(mA)
500
BAT
495
I
490
485
480
475
470
465
–50 25 75
–25 0
TEMPERATURE (°C)
VCC = 5V
= 4V
V
BAT
R
= 3k
PROG
V
= 5V
SEL
50 100
1733 G09
sn1733 1733fs
UW
TYPICAL PERFOR A CE CHARACTERISTICS
LTC1733
PROG Pin Voltage vs V
Constant Current Mode
1.515
1.510
1.505
(V)
1.500
PROG
V
1.495
1.490
1.485
4.0 5.5 6.5
4.5 5.0
VCC (V)
Trickle Charge Current vs V
13
12
11
10
9
(% OF PROGRAMMED CURRENT)
8
BAT
I
7
4.0 5.5 6.5
4.5 5.0
VCC (V)
CC
TA = 25°C
= 3.5V
V
BAT
R
= 3k
PROG
= 5V
V
SEL
6.0 7.0
1733 G10
CC
TA = 25°C
= 2V
V
BAT
= 1.5k
R
PROG
= 5V
V
SEL
6.0 7.0
1733 G13
PROG Pin Voltage vs Temperature
Constant Current Mode
1.515
1.510
1.505
(V)
1.500
PROG
V
1.495
1.490
1.485
–50 25 75
–25 0
TEMPERATURE (°C)
50 100
Timer Accuracy vs Temperature
105
104
103
102
101
(%)
100
TIMER
t
99
98
97
96
95
–50 –25 0
25
TEMPERATURE(°C)
VCC = 5V
I
V
C
50 75 100 125
VCC = 5V
V
R
V
BAT
SEL
TIMER
BAT
PROG
= 5V
SEL
= 0mA
= 5V
= 0.1µF
= 4V
= 3k
1733 G11
1733 G14
Trickle Charge Current vs
Temperature
130
120
110
(mA)
100
BAT
I
90
80
70
–50 25 75
–25 0
TEMPERATURE (°C)
Timer Accuracy vs V
105
104
103
102
101
(%)
100
TIMER
t
99
98
97
96
95
4.0 5.5 6.5
4.5 5.0
V
(V)
CC
VCC = 5V
= 2V
V
BAT
= 1.5k
R
PROG
= 5V
V
SEL
50 100
1733 G12
CC
TA = 25°C
= 0mA
I
BAT
= 5V
V
SEL
= 0.1µF
C
TIMER
6.0 7.0
1733 G15
sn1733 1733fs
5
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