Features: · 0.5% Battery Voltage Accuracy
· 3% Input Current-Limit Accuracy
· 3% Charge-Current Accuracy
· SMBus 2-Wire Serial Interface
· Cycle-by-Cycle Current Limit
Battery Short-Circuit Protection
Fast Response for Pulse Charging
Fast System-Load-Transient Response
· Dual-Remote-Sense Inputs
· Monitor Outputs for
Adapter Current (4% Accuracy)
AC Adapter Detection
· 11-Bit Battery Voltage Setting
· 6-Bit Charge-Current/Input-Current Setting
· 8A (max) Battery Charger Current
· 11A (max) Input Current
· +8V to +26V Input Voltage Range
· Charges Li+, NiMH, and NiCd Battery ChemistriesApplicationNotebook Computers
Tablet PCs
Medical Devices
Portable Equipment with Rechargeable BatteriesPinout
SpecificationsDCIN, CSSN, CSIN, FBSA, FBSB to GND..............-0.3V to +28V
CSSP to CSSN, CSIP to CSIN, PGND to GND .....-0.3V to +0.3V
BST to GND........................................................-0.3V to +32V
BST to LX.............................................................-0.3V to +6V
DHI to LX............................................-0.3V to +(VBST + 0.3)V
DLO to PGND.......................................-0.3V to +(LDO + 0.3)V
LX to GND ............................................................-6V to +28V
CCI, CCS, CCV, DAC, REF,
IINP to GND......................................-0.3V to (VVCC + 0.3)V
VDD, SCL, SDA, BATSEL, ACIN, ACOK, VCC to GND,
LDO to PGND...................................................-0.3V to +6V
Continuous Power Dissipation (TA = +70°C)
28-Pin Thin QFN
(derate 20.8mW/°C above +70°C).................1666.7 mW
Operating Temperature Range ...................-40°C to +85°C
Junction Temperature................................................+150°C
Storage Temperature Range ....................-60°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.
DescriptionThe MAX8731 is an SMBus™ programmable multichemistry battery charger. The MAX8731 uses a minimal command set to easily program the charge voltage,charge current, and adapter current limit.
The MAX8731 charges one to four Li+ series cells and delivers up to 8A charge current. The MAX8731 drives n-channel MOSFETs for improved efficiency and reduced cost. Low-offset current-sense amplifiers provide high accuracy with 10m sense resistors.
The MAX8731 current-sense amplifiers provide high accuracy (3% at 3.5A) and also provide fast cycle-bycycle current-mode control to protect against battery short circuit and system load transients.
The charger employs dual remote-sense, which reduces charge time by measuring the feedback voltage directly at the battery, improving accuracy of initial transition into constant-voltage mode. The MAX8731 provides 0.5% battery voltage accuracy directly at the battery terminal.
The MAX8731 provides a digital output that indicates the presence of the AC adapter, as well as an analog output that indicates the adapter current within 4% accuracy.
The MAX8731 is available in a small 5mm x 5mm,28-pin, thin (0.8mm) QFN package. An evaluation kit is available to reduce design time. The MAX8731 is available in lead-free packages.
MAX8731 Data Sheet
