General Description
The AAT3691 BatteryManager™ is an integrated single cell Lithium-Ion (Li-Ion) battery charger IC, designed to operate from USB ports, AC adapter inputs, or from a cellular phone charger adapter up to an input voltage of typical 6.75V. For increased safety, The AAT3691 also includes over-voltage input protection (OVP) up to 28V.
The AAT3691 precisely regulates battery charge voltage and current for 4.2V Li-Ion battery cells. The charge current can be programmed up to 1.6A for ADP charging and 0.5A for USB charging by external resistors on the ADPSET/USBSET pins. In the case of an over-voltage condition of ADP or USB input power exceeding typical 6.75V, the internal series switch opens, blocking the damage to the battery and charging circuitry.
The AAT3691 also includes a no-battery present input (NOBAT). When the NOBAT indicates that no battery is present, OVP block will prevent the input power from passing through the OVP block and suspend the charging function.
Battery charging status is continuously monitored for fault conditions. In the event of a battery over voltage or chip over thermal failure, the charger will automatically shutdown, protecting the charging device, control system and battery, until the fault condition is removed. The open drain status monitor output pin (STAT) is adopted to report battery charging activity by active low.
The AAT3691 comes in a thermally enhanced, spacesaving, Pb-free 16-pin 3x4 mm TDFN package and is specified for operation over the -40°C to +85°C temperature range.
Features
• Dual Input USB and AC Adapter Input
? Programmable Constant Current from 100mA to 1.6A for ADP Charge
? Programmable Constant Current from 50mA to 0.5A for USB Charge
• No Battery Present Input Detection
• 3.0V ~ 6.75V (typical) Input Voltage Range
• Over-Voltage Input Protection up to 28V
• High Level of Integration with Internal:
? Power Device
? Reverse Current Blocking
? Current Sensing
• Automatic Recharge Sequencing
• Fast Over-Voltage Protection Turn Off and Release Turn On Time
• Full Battery Charge Auto Turn Off/Sleep Mode/Charge Termination
• Charge Status Indicator
• Automatic Trickle Charge for Battery Preconditioning
• Thermal Shutdown Protection
• Power On Reset and Soft Start
• Active Low Enable with Internal 200kΩ Resistor Pull-Down to GND
• 3x4mm TDFN Package
Applications
• Digital Still Cameras
• Mobile Phones
• Personal Data Assistants (PDAs)
• Other Li-Ion Battery Powered Devices
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AAT3691.pdf
