19-3670; Rev 0; 4/05
KIT
ATION
EVALU
E
BL
AVAILA
1A Linear Li+ Battery Chargers with Integrated Pass
FET and Thermal Regulation in 2mm x 2mm TDFN
General Description
The MAX8808X/MAX8808Y/MAX8808Z intelligent,
stand-alone constant-current/constant-voltage (CCCV),
thermally regulated linear chargers are designed for
charging a single-cell lithium-ion (Li+) battery. The
MAX8808X/MAX8808Y/MAX8808Z integrate the cur-
rent-sense circuit, MOS pass element, and thermal-reg-
ulation circuitry, and eliminate the reverse-blocking
Schottky diode to create the simplest and smallest
charging solution for handheld equipment.
The MAX8808X functions as a stand-alone charger to
control the charging sequence from the prequalification
state through fast-charge, top-off charge, and full-
charge indication. The MAX8808Y and MAX8808Z elimi-
nate the prequalification state to allow startup into a load
without a battery. Proprietary thermal-regulation circuitry
limits the die temperature when fast-charging or while
exposed to high ambient temperatures, allowing maxi-
mum charging current without damaging the IC.
The MAX8808X/MAX8808Y/MAX8808Z achieve high
flexibility by providing an adjustable fast-charge current
with an external resistor. Other features include a bat-
tery charging-status indicator (CHG), an active-low con-
trol input (EN) for the MAX8808X and MAX8808Z
(active-high control input for the MAX8808Y), and an
active-low input power-source detection output (ACOK).
The MAX8808X/MAX8808Y/MAX8808Z accept a
+4.25V to +15V supply, but disable charging when the
input voltage exceeds +7V to protect against unquali-
fied or faulty AC adapters. The MAX8808X/MAX8808Y/
MAX8808Z operate over the extended temperature
range (-40°C to +85°C) and are available in a compact
8-pin thermally enhanced 2mm x 2mm TDFN package
with 0.8mm (max) height.
Features
♦
Stand-Alone Linear 1-Cell Li+ Battery Charger
♦
No External FET, Reverse Blocking Diode, or
Current-Sense Resistor Required
♦
Programmable Fast-Charge Current (1A max)
♦
Proprietary Die Temperature Regulation Control
(+115°C)
♦
+4.25V to +15V Input Voltage Range with Input
OVP Above +7V
♦
Charge-Current Monitor for Fuel Gauging
♦
Low Dropout Voltage—300mV at 500mA
♦
Input Power-Source Detection Output (ACOK) and
Charge-Enable Input (EN or EN)
♦
Soft-Start Limits Inrush Current
♦
Charge-Status Output (CHG) for LED or
Microprocessor (µP) Interface
♦
Tiny 2mm x 2mm 8-Pin TDFN Package, 0.8mm
(max) Height
MAX8808X/MAX8808Y/MAX8808Z
Ordering Information
PART
PIN-PACKAGE
TOP
MARK
AAC
AAB
AAA
MAX8808XETA+
8 TDFN-EP* 2mm x 2mm (T822-1)
MAX8808YETA+
8 TDFN-EP* 2mm x 2mm (T822-1)
MAX8808ZETA+
8 TDFN-EP* 2mm x 2mm (T822-1)
All devices specified over the -40°C to +85°C operating range.
+Denotes
lead-free package.
*EP
= Exposed paddle.
Applications
Cellular and Cordless Phones
Smartphones and PDAs
Digital Still Cameras and MP3 Players
USB Appliances
Charging Cradles and Docks
Bluetooth
®
Equipment
OFF
ON
4.25V TO 15V
Typical Operating Circuit
IN
BATT
CHG
EN*
ISET
MAX8808X
MAX8808Y
MAX8808Z
ACOK
VL
GND
4.2V
Li+
Pin Configuration appears at end of data sheet.
Bluetooth is a registered trademark of Bluetooth SIG.
*MAX8808Y USES ACTIVE-HIGH LOGIC FOR EN.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1A Linear Li+ Battery Chargers with Integrated Pass
FET and Thermal Regulation in 2mm x 2mm TDFN
MAX8808X/MAX8808Y/MAX8808Z
ABSOLUTE MAXIMUM RATINGS
IN to GND ...............................................................-0.3V to +16V
VL, BATT,
EN, ACOK, CHG
to GND.........................-0.3V to +6V
VL, ISET to GND .......................................................-0.3V to +4V
VL to IN................................................................-16.3V to +0.3V
IN to BATT Continuous Current.............................................1.5A
Continuous Power Dissipation (T
A
= +70°C)
8-Pin 2mm x 2mm TDFN (derate 15.4mW/°C
above +70°C).............................................................1234mW
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
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.
ELECTRICAL CHARACTERISTICS
(V
IN
= 5V, V
BATT
= 4.0V, R
ACOK
= R
CHG
= 100kΩ to 5V,
EN
= unconnected (for the MAX8808X and MAX8808Z), EN = VL (for the
MAX8808Y), R
ISET
= 2.8kΩ to GND, C
VL
= 0.47µF, C
BATT
= 1µF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 1)
PARAMETER
Input Voltage Range
Input Operating Range
ACOK
Threshold
Overvoltage-Lockout Trip Point
IN Input Current
VL Output Voltage
VL Load Regulation
VL Undervoltage-Lockout Trip
Point
BATT Input Current
Maximum RMS Charge Current
Battery Regulation Voltage
Minimum BATT Bypass
Capacitance
Fast-Charge Current Loop
System Accuracy
V
BATT
= 3.5V
T
A
= 0°C to +85°C
418
I
BATT
= 1mA
V
IN
- V
BATT
, 10mV hysteresis (typ)
V
IN
rising, 100mV hysteresis (typ)
Charging (I
IN
- I
BATT
)
Disabled
OFF state (V
IN
= V
BATT
= 4.0V)
I
VL
= 100µA
I
VL
= 100µA to 2mA
V
VL
rising, 100mV hysteresis (typ)
V
IN
= 0 to 4V
Disabled
1
4.162
4.200
2.2
465
512
4.238
3.0
-5
2.74
1
1
10
10
-30
V
IN
rising
V
IN
falling
CONDITIONS
MIN
0
4.25
15
10
6.5
40
30
7
0.8
0.23
TYP
MAX
15
6.50
60
45
7.5
2
0.50
0.065
V
mV
V
µA
A
RMS
V
µF/A
mA
mA
UNITS
V
V
mV
V
2
_______________________________________________________________________________________
1A Linear Li+ Battery Chargers with Integrated Pass
FET and Thermal Regulation in 2mm x 2mm TDFN
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 5V, V
BATT
= 4.0V, R
ACOK
= R
CHG
= 100kΩ to 5V,
EN
= unconnected (for the MAX8808X and MAX8808Z), EN = VL (for the
MAX8808Y), R
ISET
= 2.8kΩ to GND, C
VL
= 0.47µF, C
BATT
= 1µF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 1)
PARAMETER
Prequal Charge Current
Die Temperature Regulation
Threshold
V
BATT
Prequal Threshold Voltage
Current-Sense Amplifier Gain,
I
BATT
to I
ISET
Regulator Dropout Voltage
(V
IN
- V
BATT
)
EN/EN Logic Input Low Voltage
EN/EN Logic Input High Voltage
EN
Internal Pulldown Resistor
EN Input Leakage Current
CHG
Output Low Voltage
CHG
Output High Leakage
Current
ACOK
Output Low Voltage
ACOK
Output High Leakage
Current
Full-Battery Detection Current
Threshold
V
BATT
rising, MAX8808X
I
BATT
= 500mA, V
ISET
= 1.4V
V
BATT
= 4.1V, I
BATT
= 425mA
4.25V < V
IN
< 6.5V
4.25V < V
IN
< 6.5V
MAX8808X and MAX8808Z only
MAX8808Y, V
EN
= 5.5V
I
CHG
= 5mA
V
CHG
= 5.5V
I
ACOK
= 5mA
V
ACOK
= 5.5V
T
A
= +25°C
T
A
= +85°C
5
0.002
10
15
T
A
= +25°C
T
A
= +85°C
0.002
0.4
1
T
A
= +25°C
T
A
= +85°C
0.002
0.4
1
1.3
100
200
400
1
T
A
= 0°C to +85°C
2.3
0.97
CONDITIONS
Percentage of the fast-charge current, V
BATT
= 2.2V,
MAX8808X
MIN
5
TYP
10
+115
2.5
1.08
250
2.7
1.19
430
0.52
MAX
15
UNITS
%
°C
V
mA/A
mV
V
V
kΩ
µA
V
µA
V
µA
%
MAX8808X/MAX8808Y/MAX8808Z
I
BATT
falling, percentage of the fast-charge current
Note 1:
Specifications are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed by
design and characterization.
_______________________________________________________________________________________
3
1A Linear Li+ Battery Chargers with Integrated Pass
FET and Thermal Regulation in 2mm x 2mm TDFN
MAX8808X/MAX8808Y/MAX8808Z
Typical Operating Characteristics
(V
IN
= 5V, V
BATT
= 4.0V,
ACOK
=
EN
= unconnected, R
ISET
= 2.8kΩ to GND, C
IN
= 1µF, C
BATT
= 1µF, C
VL
= 0.47µF, T
A
= +25°C,
unless otherwise noted.)
SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX8808X/Y/Z toc01
DISABLED-MODE SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX8808X/Y/Z toc02
CHARGE CURRENT
vs. BATTERY VOLTAGE
900
800
CHARGE CURRENT (mA)
700
600
500
400
300
200
MAX8808Y/
MAX8808Z
MAX8808X
MAX8808X/Y/Z toc03
2.0
1.8
1.6
SUPPLY CURRENT (mA)
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0
2
4
6
8
10
12
14
800
700
SUPPLY CURRENT (µA)
600
500
400
300
200
100
0
V
EN
= 5V OR
V
EN
= 0V
0
2
4
6
8
10
12
14
1000
100
0
16
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
V
BATT
(V)
16
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
CHARGE CURRENT
vs. INPUT VOLTAGE
MAX8808X/Y/Z toc04
CHARGE CURRENT
vs. INPUT VOLTAGE HEADROOM
900
800
CHARGE CURRENT (mA)
700
600
500
400
300
200
100
0
MAX8808X/Y/Z toc05
1000
900
800
CHARGE CURRENT (mA)
700
600
500
400
300
200
100
0
0
2
4
6
8
10
12
1000
14
0
50 100 150 200 250 300 350 400 450 500
(V
IN
- V
BAT
) (mV)
V
IN
(V)
BATTERY REGULATION VOLTAGE
vs. AMBIENT TEMPERATURE
MAX8808X/Y/Z toc06
CHARGE CURRENT
vs. AMBIENT TEMPERATURE
550
CHARGE CURRENT (mA)
500
450
400
350
300
250
V
BATT
= 3.2V
V
BATT
= 4V
MAX8808X/Y/Z toc07
4.240
BATTERY REGULATION VOLTAGE (V)
4.230
4.220
4.210
4.200
4.190
4.180
4.170
4.160
4.150
-40
-15
10
T
A
(°C)
35
60
600
85
200
-40
-15
10
T
A
(°C)
35
60
85
4
_______________________________________________________________________________________
1A Linear Li+ Battery Chargers with Integrated Pass
FET and Thermal Regulation in 2mm x 2mm TDFN
Pin Description
PIN
1
2
3
NAME
IN
VL
GND
FUNCTION
Input Supply Voltage. Bypass IN to GND with a 1µF or larger ceramic capacitor to improve line
noise and input transient rejection.
Internally Generated Logic Supply for IC. Bypass VL to GND with a 0.47µF ceramic capacitor.
Ground. Connect GND and exposed pad to a large copper ground plane for maximum power
dissipation. Connect GND to the exposed paddle directly under the IC.
Charge-Current Program and Fast-Charge Current Monitor. Output current from ISET is 1.08mA
per amp of battery charging current. Set the charging current by connecting a resistor from ISET
to GND. Fast-charge current = 1302V / R
ISET
Ω.
Charging Indicator.
CHG
is an open-drain output that goes low (LED capable) when charging
begins.
CHG
is high impedance when the battery current drops below 10% of the fast-charging
current, or when the IC is disabled. Connect a pullup resistor to the µP’s I/O voltage when
interfacing with a µP logic input.
Logic-Level Enable Input. Drive
EN
high to disable charger. Pull
EN
low or leave unconnected for
normal operation.
EN
has an internal 200kΩ pulldown resistor.
Logic-Level Enable Input. Drive EN low to disable charger. Pull EN high for normal operation. EN
has no internal pullup or pulldown resistor.
Input Status Indicator.
ACOK
is an open-drain output that asserts low when V
IN
< +7V and (V
IN
–
V
BATT
)
≥
40mV.
ACOK
requires an external 100kΩ pullup resistor.
ACOK
is high impedance
during shutdown.
Li+ Battery Connection. Bypass BATT to GND with a ceramic capacitor of at least 2.2µF per
ampere of charge current.
Exposed Paddle. Connect the exposed paddle to a large ground plane for maximum power
dissipation. Connect GND to the exposed paddle directly under the IC.
MAX8808X/MAX8808Y/MAX8808Z
4
ISET
5
CHG
6
EN
(MAX8808X/
MAX8808Z)
EN
(MAX8808Y)
7
ACOK
8
—
BATT
EP
_______________________________________________________________________________________
5
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