Document
U U
FEATURES
■ 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
U APPLICATIO S
■ Cellular Telephones ■ Handheld Computers ■ Portable MP3 Players ■ Digital Cameras
LTC4077
Dual Input Standalone Li-Ion Battery Charger
DESCRIPTIO
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 compatible 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
TYPICAL APPLICATIO
Dual Input Battery Charger for Single-Cell Li-Ion
WALL ADAPTER
USB PORT
1F
LTC4077
DCIN
BAT
USBIN HPWR
1F
IUSB
2k
IDC
IUSBL
1% 1.24k
GND
1%
800mA (WALL) 500mA (USB)
+ 4.2V
SINGLE CELL Li-Ion BATTERY
2k 1%
4077 TA01
DCIN
BATTERY
CHARGE
VOLTAGE (V) VOLTAGE (V) CURRENT (mA)
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
CONSTANT VOLTAGE
USBIN = 5V TA = 25°C RIDC = 1.24k RIUSB = 2k HPWR = 5V
0 0.5 1.0 1.5 2.0 2.5 3.0 TIME (HR)
4077fa
1
U WW W
LTC4077
ABSOLUTE AXI U RATI GS
(Notes 1, 9)
Input Supply Voltage (DCIN, USBIN) ......... –0.3V to 10V EN, CHRG, PWR, 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
UW U PACKAGE/ORDER I FOR ATIO
TOP VIEW
USBIN 1 IUSB 2 IUSBL 3 PWR 4 CHRG 5
10 DCIN
9 BAT
11
8 IDC
7 HPWR
6 EN
DD PACKAGE 10-LEAD (3mm 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 40°C/W (NOTE 3) EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER PART NUMBER DD PART MARKING
LTC4077EDD
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.
ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VDCIN = 5V, VUSBIN = 5V, HPWR = 5V unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
VDCIN VUSBIN IDCIN
IUSBIN
VFLOAT IBAT
VIDC VIUSB VIUSBL IC/IO
Supply Voltage
● 4.3
8
V
Supply Voltage
● 4.3
8
V
DCIN Supply Current
Charge Mode (Note 4), RIDC = 10k Standby Mode; Charge Terminated
Shutdown Mode (EN = 5V)
●
150
700
µA
●
50
100
µA
20
40
µA
USBIN Supply Current Regulated Output (Float) Voltage BAT Pin Current
IDC Pin Regulated Voltage
Charge Mode (Note 5), RIUSB = RIUSBL = 10k,
VDCIN = 0V
●
Standby Mode; Charge Terminated, VDCIN = 0V ●
Shutdown (VDCIN = 0V, EN = 5V)
VDCIN > VUSBIN
150
700
µA
50
100
µA
18
36
µA
10
20
µA
IBAT = 1mA (Note 9)
4.175 4.2 4.225
V
IBAT = 1mA, 0°C < TA < 85°C, 4.3V < VCC < 8V
4.158 4.2 4.242
V
RIDC = 1.25k, Constant-Current Mode RIUSB =.