RY4056AP8

RY4056 is a complete constant-current/constant-voltage linear charger designed for single-cell lithium-ion batteries. Its ESOP8 package and minimal external component requirements make it ideal for portable applications. In addition, RY4056 is designed to operate within USB power specifications. The internal MOSFET architecture eliminates the need for external sense resistors and blocking diodes. A thermal feedback function regulates the charge current to limit the die temperature during high-power operation or elevated ambient temperatures. The charge voltage is fixed at 4.2V, and the charge current is programmable via a single external resistor. When the battery voltage reaches the final float voltage and the charge current drops to one-tenth of the programmed value, RY4056 automatically terminates the charge cycle. When the input power is removed, RY4056 automatically enters a low-current state, reducing battery drain to below 2µA. RY4056 can be placed in shutdown mode, reducing supply current to 25µA. Additional features include charge current monitoring, undervoltage lockout, automatic recharge, and a status pin for indicating charge termination and input voltage presence.

Applications

• Cellular phones
• Charging docks and cradles
• Bluetooth applications
• Wearable applications

Key features

• Constant current/constant voltage operation with thermal regulation to maximize charge rate without risk of overheating
• No MOSFET, sense resistor, or blocking diode required
• Complete linear charger for single-cell Li-Ion batteries
• Charges single-cell Li-Ion batteries directly from USB port
• Charge current monitor output for fuel gauging
• Automatic recharge
• Charge status output pin
• C/10 charge termination
• Programmable charge current up to 1000mA
• Preset 4.2V charge voltage with ±2% accuracy
• 25µA supply current in shutdown mode
• 2.9V trickle charge threshold
• Soft-start to limit inrush current
• Reverse battery protection
• Available in ESOP8 and DFN6-2×2 packages