SMBus Level 2 Battery Charger with Remote Sense
Low-Cost SMBus Charger with Integrated Dual n-Channel FET Drivers Deliver Up to 8A Charge Current
DescriptionThe MAX8731A is an SMBus™ programmable multi-chemistry battery charger. The MAX8731A uses a minimal command set to easily program the charge voltage, charge current, and adapter current limit.
The MAX8731A charges one to four Li+ series cells and delivers up to 8A charge current. The MAX8731A drives n-channel MOSFETs for improved efficiency and reduced cost. Low-offset current-sense amplifiers provide high accuracy with 10mΩ sense resistors.
The MAX8731A current-sense amplifiers provide high accuracy (3% at 3.5A) and also provide fast cycle-by-cycle 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 MAX8731A provides 0.5% battery voltage accuracy directly at the battery terminal.
The MAX8731A 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 MAX8731A 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 MAX8731A is available in a lead-free package.
- 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 Chemistries
- Medical Devices
- Notebook Computers
- Portable Equipment with Rechargeable Batteries
- Tablet PCs
|Part Number||Lithium Ion Cells||Protected VIN|
|Charge Rate Set by||Max. ICHG|
|Charge Termination||Charge Regulation||Oper. Temp.|
|Switchmode||-40 to +85|
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C||Material Composition|
- Optimized Feature Set for Supercapacitor Charging
- Reliable Operation in Adverse Environmental Conditions
- Up to 16V Protection
- 13.7V Maximum Input Operating Voltage
- 3.15A Maximum Charging Current
- 3.5V to 23V Input Operating Range, 30VDC Withstand Voltage
- Reverse Leakage Protection
- 50mA to 3.15A Programmable Input Current Limit
- Battery Health + Programmable Safety/Protection
- ModelGauge m5 EZ Algorithm
- Precision Measurement Without Calibration
- AEC-Q100 Grade 2 Temperature Range
- Operating Voltage from 9V to 65V
- Ultra-Low-Power Operation