GENERAL DEscriptION
The SGM41509 is a battery charger and system power path management device with integrated converter and power switches for use with single-cell Li-Ion or Li-polymer batteries. This highly integrated 5A device is capable of fast charging and supports 5V input voltage suitable for smart phones, tablets and portable systems. I2C programming makes it a very flexible powering and charger design solution.
The device includes four main power switches: input reverse blocking FET (RBFET, Q1), high-side switching FET for buck or boost mode (HSFET, Q2), low-side switching FET for buck or boost mode switching (LSFET, Q3) and battery FET that controls the interconnection of the system and battery (BATFET, Q4). The bootstrap diode for the high-side gate driving is also integrated. The internal power path has a very low impedance that reduces the charging time and maximizes the battery discharge efficiency. Moreover the input voltage and current regulations provide maximum charging power delivery to the battery with various types of input sources.
The device supports low power input voltage (5V) source and can avoid damages form high voltage source with an external N-MOSFET for over-voltage protection. The device also meets USB On-the-Go (OTG) operation power rating specification by supplying 5V (adjustable 4.5V to 5.5V) on VBUS pin with a default current limit of 2.4A (adjustable 1.2A to 4A).
The system voltage is regulated slightly above the battery voltage by the power path management circuit and is kept above the programmable minimum system voltage (3.5V by default). Therefore, system power is maintained even if the battery is completely depleted or removed. Dynamic power management (DPM) feature is also included that automatically reduces the charge current if the input current or voltage limit is reached. If the system load continues to increase after reduction of charge current down to zero, the power path management provides the deficit from battery by discharging battery to the system until the system power demand is fulfilled. This is called supplement mode and prevents input source overloading.
Starting and termination of a charging cycle can be accomplished without software control. The sensed battery voltage is used to decide for starting phase of charging in one of the three phases of charging cycle: pre-conditioning, constant current or constant voltage. When the charge current falls below a preset limit and the battery voltage is above recharge threshold, the charger function will automatically terminate and end the charging cycle. If the voltage of a charged battery falls below the recharge threshold, the charger starts another charging cycle.
Several safety features are provided in the SGM41509 such as over-voltage and over-current protections, charging safety timing, thermal shutdown and input UVLO. This device also features thermal regulation in which the charge current is reduced if the junction temperature exceeds 120℃ (selectable).
Charging status is reported by the STAT output and fault/status bits. A negative pulse is sent to the nINT output pin as soon as a fault occurs to notify the host. BATFET reset control is provided by nQON pin to exit ship mode or for a full system reset.
The device is available in a Green TQFN-4×4-24L package.
FEATURES
● High Efficiency, 1.41MHz, Synchronous Buck Charger
w Selectable PFM Mode for Light Load Efficiency
● USB On-The-Go (OTG) Support (Boost Mode)
w Boost Converter with up to 2.4A (Default) Output
w Boost Efficiency of 95.2% at 5V/1A Output
w Accurate Hiccup Mode Over-Current Protection
w Soft-Start Capable with up to 500μF Capacitive Load
w Output Short Circuit Protection
w Selectable PFM Mode for Light Load Operations
● Single Input for USB or Low Voltage Adapters
w 3.9V to 5.5V Operating Input Voltage Range
w Optional External N-MOSFET for High Input Voltage Over-Voltage Protection
w Programmable Input Current Limit and Dynamic Power Management (IINLIM, 100mA to 4.9A with 100mA Resolution) to Support USB 2.0 and USB 3.0 Standards and Low Voltage Adaptors
w Maximum Power Tracking by Input Voltage Limit up to 5.65V (VINDPM)
w VINDPM Tracking of Battery Voltage
● Resistance Compensation (IRCOMP) Function
● High Battery Discharge Efficiency with 16mΩ Switch
● Narrow Voltage DC (NVDC) Power Path Management
w Instant-On with No or Highly Depleted Battery
w Ideal Diode Operation in Battery Supplement Mode
● Ship Mode, Wake-Up and Full System Reset Capability by Battery FET Control
● Flexible Autonomous and I2C Operation Modes for Optimal System Performance
● Fully Integrated Switches, Current Sense and Compensation
● 9μA Ship Mode Low Battery Leakage Current
● High Accuracy
w ±0.5% Charge Voltage Regulation
● Safety
w Thermal Regulation and Thermal Shutdown
w Input Under-Voltage Lockout (UVLO)
w Input Over-Voltage Protection
APPLICATIONS
Tablet PC
Smart Phones, EPOS
Portable Internet Devices and Accessory