●DESCRIPTION
●The bq24741/2 is a high-efficiency, synchronous battery charger with integrated compensation, offering low component count for space-constrained Li-ion or Li-polymer battery charging applications. Ratiometric charge current and voltage programming allows high regulation accuracies, and can be either hardwired with resistors or programmed by the system power-management microcontroller using a DAC or GPIOs.
●The bq24741/2 charges two, three, or four series Li+ cells, supporting up to 10 A of charge current, and is available in a 28-pin, 5x5-mm2 thin QFN package.
●FEATURES
●• NMOS-NMOS Synchronous Buck Converter
●• Resistor-Programmable Switching Frequency between 300 kHz and 800 kHz
●• 9 V-24 V Input Voltage Operation Range
●• Support Two to Four Cells
●• Analog Inputs with Ratiometric Programming via Resistors or DAC/GPIO
● – Charge Voltage (4-4.512 V/cell)
● – Charge Current (up to 10 A)
● – Adapter Current Limit for DPM
●• High-Accuracy Voltage and Current Regulation
● – ±0.5% Charge Voltage Accuracy
● – ±3% Charge Current Accuracy
● – ±3% Adapter Current Accuracy
● – ±2% Input Current Sense Amp Accuracy
●• 150 mA Trickle-charge Current with ±33% Accuracy Down to Zero Battery Voltage
●• Safety Protection
● – Input Overvoltage Protection
● – Battery Overvoltage Protection
● – Charger Overcurrent Protection
● – Thermal Shutdown Protection
● – FET/Inductor/Battery Short Protection
●• Status and Monitoring Outputs
● – Adapter Present Indicator
● – Programmable Input Power Detect with Adjustable Threshold
● – Dynamic Power Management (DPM) with Status Indicator
● – Current Drawn from Input Source
●• Charge Enable Pin
●• Internal Soft-Start and Loop Compensation
●• 25 ns Minimum Driver Dead-Time and 99.5% Maximum Effective Duty Cycle
●• 28-pin, 5x5-mm2 QFN package
●• Energy Star Low Quiescent Current Iq
● – < 10 μA Off-State Battery Discharge Current
● – < 1.5 mA Off-State Input Quiescent Current
●APPLICATIONS
●• Notebook and Ultra-Mobile PC
●• Portable Data Capture Terminals
●• Portable Printers
●• Medical Diagnostics Equipment
●• Battery Bay Chargers
●• Battery Back-up Systems
