Maxim MAX8814, MAX8814ETA+ Datasheet

General Description
The MAX8814 intelligent, stand-alone constant-current, constant-voltage (CCCV), thermally regulated linear charger is designed for charging a single-cell lithium­ion (Li+) battery. The MAX8814 integrates the current­sense circuit, MOSFET pass element, thermal­regulation circuitry, and eliminates the reverse-blocking Schottky diode to create the simplest and smallest charging solution for handheld equipment.
The IC controls the charging sequence from the pre­qualification state through constant-current fast-charge and the final constant voltage charge. Proprietary ther­mal-regulation circuitry limits the die temperature dur­ing fast-charging or when the IC is exposed to high ambient temperatures, allowing maximum charging current without damaging the IC.
The MAX8814 achieves high flexibility by providing an adjustable fast-charge current through an external resistor. Other features include an active-low control input (EN) and an active-low input power-source detec­tion output (POK). The IC also features a booting assis­tant circuit that distinguishes input sources and battery connection and provides an output signal (ABO) for system booting.
The MAX8814 accepts an input supply range from
4.25V to 28V, but disables charging if the input voltage exceeds +7V to protect against unqualified or faulty AC adapters. The IC operates over the extended tempera­ture range (-40°C to +85°C) and is available in a com­pact 8-pin thermally enhanced TDFN 2mm x 2mm package (0.8mm max height).
Applications
Cellular and Cordless Phones
Smartphones and PDAs
MP3 Players
Digital Still Cameras
USB Appliances
Charging Cradles and Docks
Bluetooth
®
Equipment
Features
o CCCV, Thermally Regulated Linear 1-Cell Li+
Battery Charger
o No External MOSFET, Reverse Blocking Diode, or
Current-Sense Resistor
o Programmable Fast-Charge Current (1A
RMS
max)
o Proprietary Die Temperature Regulation Control
(+115°C)
o 4.25V to 28V Input Voltage Range with Input OVP
Above +7V
o Charge-Current Monitor for Fuel Gauging (ISET)
o Low Dropout Voltage (300mV at 500mA) o Input Power-Source Detection Output (POK),
Charge-Enable Input (EN)
o Soft-Start Limits Inrush Current
o Output for Autobooting (ABO)
o Tiny 2mm x 2mm, 8-Pin TDFN Package, 0.8mm
Height (max)
MAX8814
28V Linear Li+ Battery Charger with
Smart Autoboot Assistant
________________________________________________________________
Maxim Integrated Products
1
19-0994; Rev 0; 10/07
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
Ordering Information
IN
EN
ABI
ISET
GND
ABO
BATT
EP
ON
OFF
POK
SYSTEM SUPPLY
2.2μF Li+
4.25V TO 28V
MAX8814
+
Typical Operating Circuit
PART
TEMP
RANGE
PIN­PACKAGE
PKG
CODE
TOP
MARK
MAX8814ETA+
-40°C to +85°C
8 TDFN 2mm x 2mm
T822+2 ABI
Bluetooth is a registered trademark of Bluetooth SIG.
+
Denotes a lead-free and RoHS-compliant package.
Pin Configuration appears at end of data sheet.
MAX8814
28V Linear Li+ Battery Charger with Smart Autoboot Assistant
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= 5V, V
BATT
= 4V, R
POK
= 1MΩ to BATT, EN = 0V, R
ISET
= 2.8kΩ to GND, C
BATT
= 2.2µF, TA= -40°C to +85°C, unless other-
wise noted. Typical values are at T
A
= +25°C.) (Note 1)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
IN to GND ...............................................................-0.3V to +30V
ABI, BATT, EN, POK to GND....................................-0.3V to +6V
ABO to GND............................................-0.3V to (V
BATT
+ 0.3V)
ISET to GND .............................................................-0.3V to +4V
IN to BATT Continuous Current .........................................1A
RMS
Continuous Power Dissipation (TA= +70°C)
8-Pin TDFN (derate 11.9mW/°C above +70°C)
(multilayer PCB) ........................................................953.5mW
BATT Short-Circuit Duration .......................................Continuous
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Voltage Range 028V
Input Operating Voltage Range 4.25 6.50 V
VIN rising 40
Power-OK Threshold
V
IN
- V
BATT
,
10mV hysteresis (typ)
V
IN
falling 30
mV
Overvoltage-Lockout Trip Threshold
V
IN
rising, 100mV hysteresis (typ) 6.5 7 7.5 V
Constant-current charging mode (I
BATT
= 0A) 0.8 1.35
IC disabled (VEN = 5V) 0.23 0.50
TA = +25°C 0.021 0.065
IN Input Current
V
IN
= 4V,
V
BATT
= 4.2V
T
A
= +85°C 0.021
mA
VIN = 0 to 4V, V
BATT
= 4.2V
110
BATT Input Current
IC disabled 3
µA
T
A
= 0°C to +85°C 4.179 4.200 4.221
Battery Regulation Voltage I
BATT
= 0A
T
A
= -40°C to +85°C 4.158 4.200 4.242
V
Minimum BATT Bypass Capacitance
2.2 µF
T
A
= 0°C to +85°C 524 570 616
V
BATT
= 3.5V
T
A
= -40°C to +85°C 485 570 656
T
A
= 0°C to +85°C 89 107 125
Fast-Charge Current
V
BATT
= 3.5V,
R
ISET
= 14kΩ
T
A
= -40°C to +85°C 80 107 134
mA
Prequalification Charge Current
Percentage of the fast-charge current, V
BATT
= 2.2V,
T
A
= 0°C to +85°C
41015%
Die Temperature Regulation Threshold
+115 °C
V
BATT
Prequalification Threshold
Voltage
V
BATT
rising, 100mV hysteresis (typ) 2.3 2.5 2.7 V
Current-Sense Amplifier Gain (I
BATT
to I
ISET
)
I
BATT
= 570mA 877.2 µA/A
MAX8814
28V Linear Li+ Battery Charger with
Smart Autoboot Assistant
_______________________________________________________________________________________ 3
PARAMETER CONDITIONS MIN TYP MAX UNITS
Regulator Dropout Voltage (V
IN
- V
BATT
)
V
BATT
= 4.1V, I
BATT
= 425mA 240 500 mV
EN Logic-Input Low Voltage 4.25V < VIN < 6.5V 0.4 V EN Logic-Input High Voltage 4.25V < VIN < 6.5V 1.3 V
EN and ABI Internal Pulldown
Resistance
100 200 400 kΩ
ABI Logic-Input Low Voltage VIN = 0V 0.4 V
ABI Logic-Input High Voltage VIN = 0V 1.3 V
ABO Output Low Voltage I
ABO (SINK)
= 1mA 0.4 V
ABO Output High Voltage I
ABO (SOURCE)
= 1mA
V
BATT
-
0.4V
V
POK Output Low Voltage I
POK
= 5mA 0.4 V
TA = +25°C 0.001 1
POK Output High Leakage Current
V
POK
= 5.5V
T
A
= +85°C 0.002
µA
ELECTRICAL CHARACTERISTICS (continued)
(VIN= 5V, V
BATT
= 4V, R
POK
= 1MΩ to BATT, EN = 0V, R
ISET
= 2.8kΩ to GND, C
BATT
= 2.2µF, TA= -40°C to +85°C, unless other-
wise noted. Typical values are at T
A
= +25°C.) (Note 1)
Note 1: Specifications are 100% production tested at TA= +25°C. Limits over the operating temperature range are guaranteed by
design and characterization.
Typical Operating Characteristics
(VIN= 5V, V
BATT
= 4V, R
POK
= 1MΩ to BATT, EN = 0V, R
ISET
= 2.8kΩ to GND, C
BATT
= 2.2µF, TA= -40°C to +85°C, unless other-
wise noted. Typical values are at T
A
= +25°C.)
0
0.3
0.2
0.1
0.5
0.4
0.9
0.8
0.7
0.6
1.0
0 4 8 1216202428
SUPPLY CURRENT
vs. VOLTAGE
MAX8814 toc01
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
EN = 0V
0
100
200
300
400
500
600
700
800
0105 15202530
DISABLED MODE SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX8814 toc02
INPUT VOLTAGE (V)
SUPPLY CURRENT (μA)
VEN = 5V
0
200
100
400
300
600
500
700
900
800
1000
0 1.0 1.5 2.00.5 2.5 3.0 3.5 4.0 4.5
CHARGE CURRENT
vs. BATTERY VOLTAGE
MAX8814 toc03
BATTERY VOLTAGE (V)
CHARGE CURRENT (mA)
MAX8814
28V Linear Li+ Battery Charger with Smart Autoboot Assistant
4 _______________________________________________________________________________________
0
300
200
100
500
400
900
800
700
600
1000
0 4 8 12 16 20 24 28
CHARGE CURRENT
vs. INPUT VOLTAGE
MAX8814 toc04
INPUT VOLTAGE (V)
CHARGE CURRENT (mA)
0
300
200
100
400
500
600
700
800
900
1000
0 200100 300 400 500
CHARGE CURRENT vs. INPUT
VOLTAGE HEADROOM
MAX8814 toc05
VIN - V
BATT
(mV)
CHARGE CURRENT (mA)
V
BATT
= 4V
V
IN
RISING
40
μs/div
STARTUP INTO PRECHARGE
100mA/div
MAX8814 toc06
0A 5V/div
5V/div
5V/div
0V
0V
0V
I
BATT
V
IN
V
EN
V
POK
V
BATT
= 2V
100μs/div
SHUTDOWN
(FAST-CHARGE TO SHUTDOWN)
500mA/div
MAX8814 toc07
0A
0V
5V/div
5V/div
5V/div
0V
0V
I
BATT
V
IN
V
EN
V
POK
-1.0
-0.4
-0.6
-0.8
-0.2
0
0.2
0.4
0.6
0.8
1.0
-40 10-15 35 60 85
BATTERY REGULATION VOLTAGE
ACCURACY vs. AMBIENT TEMPERATURE
MAX8814 toc08
TEMPERATURE (°C)
BATTERY REGULATION VOLTAGE ACCURACY (%)
I
BATT
= 0A
CHARGE CURRENT vs. R
ISET
MAX8814 toc09
R
ISET
(kΩ)
CHARGE CURRENT (mA)
100010010
10
100
1000
1
1 10,000
0
200
100
400
300
600
500
700
-40 10-15 356085
CHARGE CURRENT vs. AMBIENT
TEMPERATURE
MAX8814 toc10
TEMPERATURE (°C)
CHARGE CURRENT (mA)
R
ISET
= 2.8kΩ
V
BATT
= 4V
V
BATT
= 3.2V
4μs/div
AUTOBOOT ENABLED
BY ABI SIGNAL
MAX8814 toc11
0V
0V
5V/div
5V/div
5V/div
5V/div
0V
0V
V
ABI
V
IN
V
BATT
V
ABO
4μs/div
AUTOBOOT ENABLED
BY INPUT SUPPLY
MAX8814 toc12
0V
5V/div
0V
5V/div
5V/div
5V/div
0V
0V
V
ABI
V
IN
V
BATT
V
ABO
Typical Operating Characteristics (continued)
(VIN= 5V, V
BATT
= 4V, R
POK
= 1MΩ to BATT, EN = 0V, R
ISET
= 2.8kΩ to GND, C
BATT
= 2.2µF, TA= -40°C to +85°C, unless other-
wise noted. Typical values are at T
A
= +25°C.)
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