ME4069ASPG

ME4069 is a constant-current/constant-voltage lithium battery charge controller based on a current-mode PWM buck switching architecture. The charge current is set by an external sense resistor connected between the SEN and BAT pins. The float voltage for a single-cell battery is internally set to 4.20V. For lithium batteries requiring high-accuracy float voltage, the integrated reference voltage, error amplifier, and resistor divider provide precise float voltage regulation. The charge cycle begins when the VIN input voltage 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 10% of the full charge current. Once the battery voltage exceeds the trickle charge threshold, the charger transitions to full constant-current (CC) charge mode. In CC mode, the charge current is set via an external sense resistor R5 and an internal 100mV reference voltage: IOUT = 100mV/R5. As the battery voltage approaches the float voltage, the charge current begins to decrease. When the charge current drops to 10% of the full charge current, an internal comparator turns off the pull-down N-channel MOSFET at the CHRG pin to indicate that the charge cycle is nearing termination; when the charge cycle terminates, the CHRG pin is forced to high impedance. To restart the charge cycle, remove and reapply the input voltage, or disable the charger momentarily. Similarly, if the single-cell battery voltage falls below the recharge threshold voltage, a new charge cycle begins. Once the battery is fully charged, if the input voltage remains applied, the charger shuts down; when the input voltage is removed, the charger enters sleep mode, which significantly reduces battery current consumption and extends standby time. The TEMP pin should be connected to a 20KΩ resistor to GND during normal operation. When battery temperature monitoring is required, connect a negative temperature coefficient (NTC) resistor to GND to detect whether the battery temperature is within the acceptable range. If the temperature falls outside the 0~50℃ 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 blocking
• Built-in overvoltage protection at 6V
• Built-in soft-start to prevent large inrush current at power-up
• High-efficiency current-mode PWM buck switching control architecture
• End-of-charge current detection output
• Fixed switching frequency for minimum noise
• ±1% charge voltage (4.2V) accuracy
• Automatic recharge
• Automatic sleep mode upon input power removal
• Automatic trickle charge mode at low battery voltage
• Stable output with low-ESR ceramic capacitors
• Battery temperature sensing