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MAX8845XETC+

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P19
General Description
The MAX8845Z/MAX8845Y/MAX8845X/MAX8845W are
intelligent, stand-alone constant-current, constant-volt-
age (CCCV), thermally regulated linear chargers
designed for charging a single-cell lithium-ion (Li+) bat-
tery. The MAX8845Z/MAX8845Y/MAX8845X/MAX8845W
integrate a current-sense circuit, MOSFET pass element,
thermal-regulation circuitry, and eliminate the external
reverse-blocking Schottky diode to create the simplest
and smallest charging solutions for handheld equipment.
The ICs control the charging sequence from the pre-
qualification state through constant current fast-charge,
top-off charge, and full-charge indication. Proprietary
thermal-regulation circuitry limits the die temperature
during fast-charging or when the ICs are exposed to
high ambient temperatures, allowing maximum charg-
ing current without damaging the ICs.
The MAX8845Z/MAX8845Y/MAX8845X/MAX8845W
achieve high flexibility by providing adjustable fast-
charge currents (SETI) and an adjustable top-off cur-
rent threshold (MIN) through external resistors. The
MAX8845Z/MAX8845Y/MAX8845X/MAX8845W feature
a booting assistant circuit that distinguishes input
sources and battery connection and provides an
enable signal (ABO—MAX8845Z and ABO—
MAX8845Y/MAX8845X/MAX8845W) for system booting.
The MAX8845Z/MAX8845Y/MAX8845X/MAX8845W also
integrate an overvoltage-protected output (SAFEOUT) for
low voltage-rated USB or charger inputs in system, and a
battery-pack detection circuit (DETBAT) that disables the
charger when the battery pack is absent. Other features
include an active-low control input (EN), an active-low
input power source detection output (POK), and a fully
charged top-off threshold detection output (CHG).
The MAX8845Z/MAX8845Y/MAX8845X/MAX8845W
accept an input supply range from 4.25V (4.4V for
MAX8845W only) to 28V, but disable charging if the
supply voltage exceeds +7.5V (+8.0V for MAX8845X
only) to protect against unqualified or faulty AC
adapters. The ICs operate over the extended tempera-
ture range (-40°C to +85°C) and are available in a com-
pact 12-pin, thermally enhanced thin QFN, 3mm x 3mm
package (0.8mm max height).
Applications
Cellular and Cordless Phones
Smart Phones and PDAs
Digital Still Cameras
MP3 Players
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 Currents (1A
RMS
max)
o Programmable Top-Off Current Threshold (MIN)
o Input Overvoltage Protected 4.7V Output
(MAX8845Z/MAX8845Y/MAX8845W) or 4.85V
(MAX8845X) (SAFEOUT)
o Proprietary Die Temperature Regulation Control
(+115°C)
o 4.25V (4.4V for MAX8845W only) to 28V Input
Voltage Range with Input Overvoltage Protection
Above +7.5V (+8.0V for MAX8845X only)
o Low-Dropout Voltage (300mV at 500mA)
o Input Power-Source Detection Output (POK),
Charge Status Output (CHG), Charge-Enable Input
(EN)
o Output for Autobooting (ABO—MAX8845Z,
ABO—MAX8845Y/MAX8845X/MAX8845W)
o Tiny, 3mm x 3mm 12-Pin Thin QFN Package,
0.8mm Height (max)
MAX8845Z/MAX8845Y/MAX8845X/MAX8845W
28V Linear Li+ Battery Chargers with Battery
Detection and Overvoltage Protected Output
________________________________________________________________
Maxim Integrated Products
1
19-4340; Rev 1; 9/09
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
PART PIN-PACKAGE
TOP
MARK
ABO
ACTIVE
STATE
MAX8845ZETC+ 12 Thin QFN-EP* ABL Active high
MAX8845YETC+ 12 Thin QFN-EP* ABM Active low
MAX8845XETC+ 12 Thin QFN-EP* ABQ Active low
MAX8845WETC+ 12 Thin QFN-EP* ABR Active low
Note: All devices are specified over the -40°C to +85°C oper-
ating temperature range.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
*
EP = Exposed pad.
Bluetooth is a registered trademark of Bluetooth SIG.
Typical Operating Circuit and Pin Configurations appear at
end of data sheet.
MAX8845Z/MAX8845Y/MAX8845X/MAX8845W
28V Linear Li+ Battery Chargers with Battery
Detection and Overvoltage Protected Output
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= 5V, V
BATT
= 4V, R
POK
= 1MΩ to BATT, EN = unconnected, R
SETI
= 2.8kΩ to GND, V
DETBAT
= 0, C
BATT
= 2.2µF, T
A
= -40°C to
+85°C, unless otherwise 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, ABO, ABO, CHG, DETBAT, SETI, MIN,
SAFEOUT to GND ................................................-0.3V to +6V
IN to BATT Continuous Current .........................................1A
RMS
Continuous Power Dissipation (T
A
= +70°C)
12-Thin QFN (derate 14.7mW/°C above +70°C)
(multilayer PCB) ......................................................1176.5mW
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 Supply Voltage Range 0 28 V
4.25 7.00
Input Supply Operating Voltage Range
MAX8845W only 4.40 7.00
V
V
IN
rising, 100mV hysteresis (typ) 7.0 7.5 8.0
Overvoltage Lockout Trip Threshold
MAX8845X only 7.5 8.0 8.5
V
Constant current charging
I
IN
- I
BATT
,
I
BATT
= 0
0.22 0.50
Constant current charging
I
IN
- I
BATT,
I
BATT
= 500mA
1
IC disabled, V
EN
= 5V 0.20 0.50
T
A
= +25°C 0.02
Input Current
V
IN
= 4V,
V
BATT
= 4.2V (4.35V for
MAX8845W only)
T
A
= +85°C 0.03
mA
BATT, CHG, POK
Minimum BATT Bypass Capacitance 2.2 µF
V
BATT
Prequalification Threshold Voltage V
BATT
rising, 100mV hysteresis (typ) 2.3 2.5 2.7 V
4.175 4.200 4.225
I
BATT
= 0 T
A
= -40°C to +85°C
4.158 4.200 4.242
4.324 4.350 4.376
Battery Regulation Voltage
MAX8845W only
4.306 4.350 4.394
V
Regulator Dropout Voltage (V
IN
- V
BATT
)V
BATT
= 4.1V, I
BATT
= 425mA 260 mV
V
IN
= 0 to 4V,
V
BATT
= 4.2V (4.35V for MAX8845W only)
510
BATT Input Current
IC disabled 3
µA
Current-Sense Amplifier Gain (I
BATT
to I
SETI
)I
BATT
= 500mA 1016 µA/A
T
A
= 0°C to +85°C 460 500 540
V
BATT
= 3.5V,
R
SETI
= 2.8kΩ
T
A
= -40°C to +85°C 425 500 575
Fast-Charge Current
V
BATT
= 3.5V,
R
SETI
= 14kΩ
T
A
= 0°C to +85°C 85 100 115
mA
CHG Top-Off Threshold
I
BATT
falling, battery is charged
R
MIN
= 1.75kΩ
106 mA
MAX8845Z/MAX8845Y/MAX8845X/MAX8845W
28V Linear Li+ Battery Chargers with Battery
Detection and Overvoltage Protected Output
_______________________________________________________________________________________ 3
PARAMETER CONDITIONS MIN TYP MAX UNITS
CHG Hysteresis
I
BATT
rising after top-off is detected,
R
MIN
= 1.75kΩ
38 mA
CHG Detection Delay I
BATT
falls below top-off threshold 4.0 6.2 10.7 ms
Prequalification Charge Current
Percentage of the fast-
charge current, V
BATT
= 2.2V
T
A
= 0°C to +85°C 5 10 15 %
CHG, POK Output Low Threshold I
POK
= 5mA , I
CHG
= 5mA 0.4 V
T
A
= +25°C 1
CHG, POK Output High Leakage Current
V
POK
= 5.5V,
V
CHG
= 5.5V
T
A
= +85°C 0.01
µA
V
IN
rising 40
POK Threshold V
IN
- V
BATT
V
IN
falling 30
mV
DETBAT, SAFEOUT
DETBAT Logic-Input Low Threshold 0.4
DETBAT Logic-Input High Threshold 1.3
V
DETBAT Pullup Resistor DETBAT to V
L
= 3V 470 kΩ
Minimum SAFEOUT Bypass Capacitance 1 µF
I
SAFEOUT
= 30mA, V
IN
= 5V, T
A
= 0°C to
+85°C (MAX8845Z/MAX8845Y/MAX8845W)
4.5 4.7 4.9
SAFEOUT Regulated Output
I
SAFEOUT
= 20mA, V
IN
= 5V, T
A
= 0°C to
+85°C (MAX8845X)
4.75 4.85 5.0
V
SAFEOUT Current Limit 100 mA
EN, ABI, ABO, ABO
EN, ABI Internal Pulldown Resistor 100 200 400 kΩ
EN Logic-Input Low Threshold 4.25V (4.4V for MAX8845W only) ≤ V
IN
≤ 7V 0.4 V
EN Logic-Input High Threshold 4.25V (4.4V for MAX8845W only) ≤ V
IN
≤ 7V 1.3 V
ABI Logic-Input Low Threshold V
BATT
= 4V, V
IN
= 0 0.4 V
ABI Logic-Input High Threshold V
BATT
= 4V, V
IN
= 0 1.3 V
ABO Output Low Threshold (MAX8845Y/
MAX8845X/MAX8845W)
Open drain, I
ABO(SINK)
= 1mA 0.4 V
ABO Output High Threshold (MAX8845Y/
MAX8845X/MAX8845W)
Open drain, 100kΩ pullup to BATT
V
BATT
-
0.4V
V
ABO Output Low Threshold
(MAX8845Z)
I
ABO(SINK)
= 1mA 0.4 V
ABO Output High Threshold (MAX8845Z) I
ABO(SOURCE)
= 1mA
V
BATT
-
0.4V
V
THERMAL
Die Temperature Regulation Threshold 115 °C
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 5V, V
BATT
= 4V, R
POK
= 1MΩ to BATT, EN = unconnected, R
SETI
= 2.8kΩ to GND, V
DETBAT
= 0, C
BATT
= 2.2µF, T
A
= -40°C to
+85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
Note 1: Specifications are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed by
design and characterization.
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P19

MAX8845XETC+

Mfr. #:
Buy MAX8845XETC+
Manufacturer:
Maxim Integrated
Description:
Battery Management 28V Linear Li+ Battery Charger
Lifecycle:
New from this manufacturer.
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