ME4059ASPG-N

ME4059-N is a lithium battery charge management IC featuring constant current/constant voltage (CC/CV) charging modes. It enables fast and efficient charging of single-cell (4.2V/4.34V) lithium batteries. Employing a current-mode PWM buck switching control architecture, it provides a compact, simple, and highly efficient solution for fast lithium battery charging. ME4059-N integrates a reverse-current blocking function, eliminating the need for an input blocking diode in practical applications and significantly reducing system cost. The IC also integrates overvoltage protection: when VIN exceeds 6V, the IC shuts down, and the VIN pin can withstand up to 10V at that point. ME4059-N sets a high-accuracy charge current via an external sense resistor. Internally, a resistor divider and a precision reference voltage set the battery float voltage to 4.2V/4.34V with accuracy up to ±1%. When the input power is removed, the IC automatically enters a low-current sleep mode, reducing battery leakage current to as low as 1μA. At the end of a charge cycle, if the single-cell voltage drops to 4.1V/4.15V, the IC will automatically initiate a new charge cycle. ME4059-N is a CC/CV lithium battery charge controller based on a current-mode PWM buck switching architecture. The charge current is set by a sense resistor connected between the SEN and BAT pins. The single-cell float voltage is internally set to 4.20V/4.34V. For lithium batteries requiring a highly accurate float voltage, the integrated reference voltage, error amplifier, and resistor divider provide high-precision float voltage regulation. A charge cycle begins when VIN exceeds the battery voltage by more than 100mV. At the start of the charge cycle, if the battery voltage is below the trickle charge threshold, the charger enters trickle charge mode, with the trickle charge current internally set to 25% of full-scale current. Once the battery voltage exceeds the trickle charge threshold, the charger transitions to full-scale constant current (CC) mode. In CC mode, the charge current is set by external sense resistor R5 and an internal 125mV reference voltage: IOUT = 125mV/R5. As the battery voltage approaches the float voltage, the charge current begins to decrease. When the charge current falls to 25% of the full-scale charge current, an internal comparator turns off the pull-down N-channel MOSFET at the CHRG pin and connects a micro-current source to GND to indicate that the charge cycle is approaching termination. When the charge cycle terminates, the CHRG pin is forced to high impedance. To restart the charge cycle, the input voltage can be removed and reapplied, or the charger can be briefly disabled. Likewise, if the single-cell battery voltage drops below the recharge threshold voltage, a new charge cycle begins. Once the battery is fully charged, if the input voltage is not removed, the charger shuts down; when the input voltage is removed, the charger enters sleep mode, significantly reducing battery current consumption and extending standby time. The TEMP pin is connected to a 20KΩ resistor to GND during normal operation. When battery temperature monitoring is required, a negative temperature coefficient (NTC) resistor to GND is used to detect whether the battery temperature is within the acceptable range. If the temperature falls outside the 0~50°C range, the charge cycle will be suspended.

Applications

• Charging equipment
• Portable laptops
• Handheld devices

Key features

• Input supply voltage operating range: 4.7V - 5.5V
• Built-in reverse current protection
• Built-in overvoltage protection, 10V withstand voltage at chip input
• Built-in soft-start to prevent large inrush current at power-on
• High-efficiency current-mode PWM buck switching control architecture
• End-of-charge current detection output
• Fixed switching frequency for minimal noise
• ±1% charge voltage (4.2V/4.34V) accuracy
• Automatic recharge
• Auto sleep mode upon input power removal
• Auto trickle charge mode at low battery voltage
• Stable output with low-ESR ceramic capacitors
• Battery temperature detection