SE9019

SE9019 is a constant-current/constant-voltage lithium battery charge controller featuring 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 is internally set to 4.20V/4.35V (typical).

Applications

• Backup power supply
• Portable devices
• Li-ion battery charger
• Handheld devices

Key features

• Single-cell lithium battery charging with CC/CV mode
• 1MHz (Typ) fixed switching frequency
• MPPT (Maximum Power Point Tracking)
• Built-in reverse current blocking, no external diode required
• Charge voltage 4.2V/4.35V ±1%
• Programmable charge current
• Trickle charging
• Auto-recharge
• Sleep mode
• Single LED charge status indicator
• Under-voltage protection
• Over-temperature protection
• Li-battery temperature detection and protection
• SOP8-EP package
• Input voltage range: 4.7V~5.5V
• Three-stage charge management: when battery voltage is below 2.9V (Typ), trickle charge mode is applied with charge current at 1/10 (Typ) of full charge current; when battery voltage exceeds 2.9V (Typ), full current charging is applied with charge current set by external SENSE resistor; when battery approaches float voltage, constant voltage charging is applied with gradually decreasing charge current; when charge current drops to 1/10 (Typ) of full current, charging is complete; if battery voltage drops to recharge threshold 4.0V (Typ), charging restarts automatically; when input power is removed, the IC automatically enters sleep mode and battery leakage current drops to 2uA (Typ)
• Battery temperature detection and protection via external NTC thermistor; charging stops when TEMP < 0.35V or TEMP > 2.4V; this function can be disabled when TEMP < 80mV