LTC4077
Dual Input Standalone
Li-Ion Battery Charger
Charges Single-Cell Li-Ion Batteries from Wall
Adapter and USB Inputs
Automatic Input Power Detection and Selection
Charge Current Programmable up to 950mA from
Wall Adapter Input
C/10 Charge Current Termination
Thermal Regulation Maximizes Charge Rate
Without Risk of Overheating*
Preset Charge Voltage with ±0.6% Accuracy
18µA USB Suspend Current in Shutdown
Power Present Status Output
Charge Status Output
Automatic Recharge
Available in a Thermally Enhanced, Low Profile
(0.75mm) 10-Lead (3mm
×
3mm) DFN Package
The LTC
®
4077 is a standalone linear charger that is capable
of charging a single-cell Li-Ion battery from both wall
adapter and USB inputs. The charger can detect power at
the inputs and automatically select the appropriate power
source for charging.
No external sense resistor or blocking diode is required
for charging due to the internal MOSFET architecture.
Internal thermal feedback regulates the battery charge
current to maintain a constant die temperature during high
power operation or high ambient temperature conditions.
The float voltage is fixed at 4.2V and the charge current
is programmed with an external resistor. The LTC4077
terminates the charge cycle when the charge current drops
below the termination threshold after the final float voltage
is reached. The LTC4077 can be put into shutdown mode
reducing the DCIN supply current to 20µA, the USBIN
supply current to 10µA, and the battery drain current to
less than 2µA even with power applied to both inputs.
Other features include automatic recharge, undervoltage
lockout, charge status output, power present status output
to indicate the presence of wall adapter or USB power and
high power/low power adjustable mode for USB compat-
ible applications.
, 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
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APPLICATIO S
■
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Cellular Telephones
Handheld Computers
Portable MP3 Players
Digital Cameras
Dual Input Battery Charger for Single-Cell Li-Ion
LTC4077
DCIN
1 F
USBIN
IUSB
GND
IUSBL
2k
1%
4077 TA01
WALL
ADAPTER
USB
PORT
1 F
800mA (WALL)
500mA (USB)
BAT
BATTERY
CHARGE
VOLTAGE (V) CURRENT (mA)
HPWR
DCIN
VOLTAGE (V)
2k
IDC
1% 1.24k
1%
U
TYPICAL APPLICATIO
Complete Charge Cycle (1100mAh Battery)
1000
800
600
400
200
0
4.2
4.0
3.8
3.6
3.4
5.0
2.5
0
0
0.5
1.0
1.5
2.0
TIME (HR)
2.5
3.0
4077fa
+
4.2V
SINGLE CELL
Li-Ion BATTERY
U
CONSTANT VOLTAGE
USBIN = 5V
T
A
= 25°C
R
IDC
= 1.24k
R
IUSB
= 2k
HPWR = 5V
FEATURES
DESCRIPTIO
U
1
LTC4077
(Notes 1, 9)
Input Supply Voltage (DCIN, USBIN) ......... –0.3V to 10V
E
N,
C
H
R
G,
P
W
R, HPWR ............................ –0.3V to 10V
BAT, IDC, IUSB, IUSBL ................................. –0.3V to 7V
DCIN Pin Current (Note 6) ..........................................1A
USBIN Pin Current (Note 6) .................................700mA
BAT Pin Current (Note 6) ............................................1A
BAT Short-Circuit Duration............................ Continuous
Maximum Junction Temperature .......................... 125
°
C
Operating Temperature Range (Note 2) .. –40
°
C to 85
°
C
Storage Temperature Range.................. –65
°
C to 125
°
C
TOP VIEW
USBIN
IUSB
IUSBL
PWR
CHRG
1
2
3
4
5
11
10 DCIN
9 BAT
8 IDC
7 HPWR
6 EN
DD PACKAGE
10-LEAD (3mm 3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 40°C/W (NOTE 3)
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER PART NUMBER
LTC4077EDD
DD PART MARKING
LBWD
Order Options
Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DCIN
= 5V, V
USBIN
= 5V, HPWR = 5V unless otherwise noted.
SYMBOL
V
DCIN
V
USBIN
I
DCIN
PARAMETER
Supply Voltage
Supply Voltage
DCIN Supply Current
CONDITIONS
●
●
ELECTRICAL CHARACTERISTICS
MIN
4.3
4.3
TYP
MAX
8
8
700
100
40
700
100
36
20
4.225
4.242
840
500
108
56
–6
–2
±2
1.05
1.05
0.22
0.11
0.11
UNITS
V
V
µA
µA
µA
µA
µA
µA
µA
V
V
mA
mA
mA
mA
µA
µA
µA
V
V
V
mA/mA
mA/mA
I
USBIN
USBIN Supply Current
V
FLOAT
I
BAT
Regulated Output (Float) Voltage
BAT Pin Current
V
IDC
V
IUSB
V
IUSBL
I
C/IO
IDC Pin Regulated Voltage
IUSB Pin Regulated Voltage
IUSBL Pin Regulated Voltage
Charge Current Termination Threshold
Charge Mode (Note 4), R
IDC
= 10k
Standby Mode; Charge Terminated
Shutdown Mode (EN = 5V)
Charge Mode (Note 5), R
IUSB
= R
IUSBL
= 10k,
V
DCIN
= 0V
Standby Mode; Charge Terminated, V
DCIN
= 0V
Shutdown (V
DCIN
= 0V, EN = 5V)
V
DCIN
> V
USBIN
I
BAT
= 1mA (Note 9)
I
BAT
= 1mA, 0°C < T
A
< 85°C, 4.3V < V
CC
< 8V
R
IDC
= 1.25k, Constant-Current Mode
R
IUSB
= 2.1k, Constant-Current Mode
R
IDC
= 10k or R
IUSB
= 10k
R
IUSBL
= 4k, HPWR = 0
Standby Mode, Charge Terminated
Shutdown Mode (Charger Disabled)
Sleep Mode (V
DCIN
= 0V, V
USBIN
= 0V)
Constant-Current Mode
Constant-Current Mode
Constant-Current Mode
V
DCIN
= 5V, R
IDC
= 1.25k (Note 7)
V
USBIN
= 5V, V
DCIN
= 0V
●
●
150
50
20
150
50
18
10
4.2
4.2
800
476
100
50
–3
–1
±1
1
1
0.2
0.1
0.1
●
●
●
●
●
●
4.175
4.158
760
450
92
44
●
●
0.95
0.95
0.18
0.09
0.09
4077fa
2
U
W
U
U
W W
W
ABSOLUTE
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
LTC4077
ELECTRICAL CHARACTERISTICS
SYMBOL
I
C/2
I
TRIKL
PARAMETER
Charge Current Termination Threshold
Trickle Charge Current
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DCIN
= 5V, V
USBIN
= 5V, HPWR = 5V unless otherwise noted.
CONDITIONS
HPWR = 0V (Note 8)
V
BAT
< V
TRIKL
; R
IDC
= 1.25k
V
BAT
< V
TRIKL
; R
IUSB
= 2.1k
V
BAT
< V
TRIKL
; R
IUSBL
= 4k
V
BAT
Rising
Hysteresis
From Low to High
Hysteresis
From Low to High
Hysteresis
V
DCIN
from Low to High, V
BAT
= 4.2V
V
DCIN
from High to Low, V
BAT
= 4.2V
V
USBIN
from Low to High
V
USBIN
from High to Low
●
●
●
MIN
0.45
60
30
17
2.8
4
3.8
140
20
140
20
0.4
1
0.4
1
TYP
0.5
80
47.5
25
2.9
100
4.15
200
3.95
200
180
50
180
50
0.7
2
0.7
2
0.35
0.35
100
6
1.5
250
400
550
105
MAX
0.55
100
65
33
3
4.3
4.1
220
80
220
80
1
5
1
5
0.6
0.6
135
10
2.2
325
UNITS
mA/mA
mA
mA
mA
V
mV
V
mV
V
mV
mV
mV
mV
mV
V
MΩ
V
MΩ
V
V
mV
ms
ms
µs
mΩ
mΩ
°C
V
TRIKL
V
UVDC
V
UVUSB
V
ASD-DC
V
ASD-USB
V
EN
R
EN
V
HPWR
R
HPWR
V
C
H
R
G
V
P
W
R
ΔV
RECHRG
t
RECHRG
t
TERMINATE
t
SS
R
ON-DC
R
ON-USB
T
LIM
Trickle Charge Threshold Voltage
DCIN Undervoltage Lockout Voltage
USBIN Undervoltage Lockout Voltage
V
DCIN
– V
BAT
Lockout Threshold
V
USBIN
– V
BAT
Lockout Threshold
EN Input Threshold Voltage
EN Pulldown Resistance
HPWR Input Threshold Voltage
HPWR Pulldown Resistance
C
H
R
G Output Low Voltage
P
W
R Output Low Voltage
Recharge Battery Threshold Voltage
Recharge Comparator Filter Time
Termination Comparator Filter Time
Soft-Start Time
Power FET “ON” Resistance
(Between DCIN and BAT)
Power FET “ON” Resistance
(Between USBIN and BAT)
Junction Temperature in
Constant-Temperature Mode
I
C
H
R
G
= 5mA
I
P
W
R
= 5mA
V
FLOAT
– V
RECHRG
, 0°C < T
A
< 85°C
V
BAT
from High to Low
I
BAT
Drops Below Termination Threshold
I
BAT
= 10% to 90% Full-Scale
65
3
0.8
175
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 LTC4077E is guaranteed to meet the 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 correctly solder the exposed backside of the package to
the PC board will result in a thermal resistance much higher than 40°C/W.
See Thermal Considerations.
Note 4:
Supply current includes IDC pin current (approximately 100µA)
but does not include any current delivered to the battery through the BAT
pin.
Note 5:
Supply current includes IUSB and IUSBL pin currents
(approximately 100µA each) but does not include any current delivered to
the battery through the BAT pin.
Note 6:
Guaranteed by long term current density limitations.
Note 7:
I
C/10
is expressed as a fraction of measured full charge current.
Note 8:
I
C/2
is expressed as a fraction of measured full charge current.
Note 9:
V
CC
is greater of DCIN or USBIN.
4077fa
3
LTC4077
TYPICAL PERFOR A CE CHARACTERISTICS
Regulated Output (Float) Voltage
vs Charge Current
4.26
4.24
4.22
V
FLOAT
(V)
V
FLOAT
(V)
4.20
4.18
4.16
4.14
4.12
4.10
0
100 200 300 400 500 600 700 800
CHARGE CURRENT (mA)
4077 G01
V
DCIN
= V
USBIN
= 5V
4.200
4.195
4.190
4.185
4.180
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4077 G02
V
IDC
(V)
R
IDC
= R
IUSB
= 2k
R
IDC
= 1.25k
IUSB Pin Voltage vs Temperature
(Constant-Current Mode)
1.008
1.006
1.004
V
IUSB
(V)
V
USBIN
= 8V
V
USBIN
= 4.3V
V
IUSBL
(V)
1.002
1.000
0.998
0.996
0.994
0.992
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4077 G04
HPWR = 5V
I
BAT
(mA)
Charge Current vs IUSB Pin
Voltage
900
800
700
600
I
BAT
(mA)
500
400
300
200
100
0
0
0.2
0.4
R
IUSB
= 10k
50
V
USBIN
= 5V
HPWR = 5V
250
R
IUSB
= 1.25k
I
PWR
(mA)
I
BAT
(mA)
R
IUSB
= 2k
0.6
0.8
V
IUSB
(V)
4
U W
1.0
4077 G06
Regulated Output (Float) Voltage
vs Temperature
4.220
4.215
4.210
4.205
V
DCIN
= V
USBIN
= 5V
1.008
1.006
1.004
1.002
1.000
0.998
0.996
0.994
IDC Pin Voltage vs Temperature
(Constant-Current Mode)
V
DCIN
= 8V
V
DCIN
= 4.3V
0.992
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
4077 G03
IUSBL Pin Voltage vs Temperature
(Constant-Current Mode)
0.208
0.206
0.204
0.202
0.200
0.198
0.196
0.194
0.192
–50
–25
50
25
TEMPERATURE (°C)
0
75
100
4077 G24
Charge Current vs IDC Pin
Voltage
900
800
700
600
V
DCIN
= 5V
R
IDC
= 1.25k
HPWR = 0V
V
USBIN
= 8V
V
USBIN
= 4.3V
500
400
300
200
100
0
0
0.2
0.4
0.6
0.8
V
IDC
(V)
R
IDC
= 2k
R
IDC
= 10k
1.0
1.2
4077 G05
Charge Current vs IUSBL Pin
Voltage
V
USBIN
= 5V
HPWR = 0V
R
IUSBL
= 1k
35
30
25
20
15
10
5
0
P
W
R Pin I-V Curve
V
DCIN
= V
USBIN
= 5V
T
A
= – 40°C
T
A
= 25°C
T
A
= 90°C
200
150
R
IUSBL
= 2k
R
IUSBL
= 4k
100
1.2
0
0
50
150
100
V
IUSBL
(mV)
200
250
4077 G25
0
1
2
4
3
V
PWR
(V)
5
6
7
4077 G07
4077fa
LTC4077
TYPICAL PERFOR A CE CHARACTERISTICS
C
H
R
G Pin I-V Curve
35
30
25
I
CHRG
(mA)
20
15
10
5
0
0
4
3
V
CHRG
(V)
5
6
7
4077 G08
V
DCIN
= V
USBIN
= 5V
I
BAT
(mA)
I
BAT
(mA)
1
2
Charge Current vs Battery Voltage
1000
550
500
450
400
350
300
800
R
DS(ON)
(mΩ)
I
BAT
(mA)
600
R
DS(ON)
(mΩ)
400
200
0
V
DCIN
= V
USBIN
= 5V
θ
JA
= 40°C/W
R
IDC
= 1.25k
2.4
2.7
3.0
3.3 3.6
V
BAT
(V)
3.9
4.2
4.5
EN Pin Threshold (Rising) vs
Temperature
900
V
DCIN
= V
USBIN
= 5V
850
800
V
HPWR
(mV)
V
EN
(mV)
750
700
650
600
–50
900
I
DCIN
(µA)
–25
50
25
0
TEMPERATURE (°C)
U W
T
A
= –40°C
T
A
= 25°C
T
A
= 90°C
4077 G11
Charge Current vs Ambient
Temperature
1000
ONSET OF
THERMAL REGULATION
R
IDC
= 1.25k
700
600
500
200
HPWR = 5V
V
DCIN
= V
USBIN
= 5V
V
BAT
= 4V
θ
JA
= 40°C/W
50
25
75
0
TEMPERATURE (°C)
100
125
400
900
800
Charge Current vs Supply Voltage
ONSET OF
THERMAL REGULATION
800
600
R
IDC
= R
IUSB
= 2k
400
0
–50 –25
R
IDC
= 1.25k
V
BAT
= 4V
θ
JA
= 35°C/W
5.0
5.5 6.0 6.5
V
DCIN
(V)
7.0
7.5
8.0
300
4.0 4.5
4077 G09
4077 G10
DCIN Power FET “On” Resistance
vs Temperature
V
BAT
= 4V
I
BAT
= 200mA
800
750
700
650
600
550
500
450
400
50
25
75
0
TEMPERATURE (°C)
100
125
USBIN Power FET “On” Resistance
vs Temperature
V
BAT
= 4V
I
BAT
= 200mA
HPWR = 5V
250
–50 –25
350
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
4077 G12
4077 G13
HPWR Pin Threshold (Rising) vs
Temperature
50
V
DCIN
= V
USBIN
= 5V
850
800
750
700
650
600
–50
45
40
35
30
25
20
15
10
5
–25
50
25
0
TEMPERATURE (°C)
75
100
DCIN Shutdown Current vs
Temperature
V
DCIN
= 8V
V
DCIN
= 5V
V
DCIN
= 4.3V
EN = 5V
–25
50
25
0
TEMPERATURE (°C)
75
100
4077 G16
75
100
4077 G14
0
–50
4077 G15
4077fa
5
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