The RT9758 is a high efficiency and high charge current charger for high voltage application. The efficiency is up to 98.1% when VOUT = 10V, IOUT = 2A, switching frequency = 500kHz, dual phase with VBUS input in cap divider mode. The RT9758 maximum charge current is up to 5A. The device integrates cap divider topology (DIV2 mode), direct charge topology (Bypass mode), an input reverse blocking NFET, a dual-phase charge pump core, the EN pin control and 9-way protection. In present mode (EN = H), the host can still order the command by I2C serial interface.

The recommended junction temperature range is -40°C to 125°C, and the ambient temperature range is -40°C to 85°C.


  • Smart Phones
  • Tablet
  • PC
Key Spec.
Status Active
Vin (min) (V) 4
Vin (max) (V) 21
Battery Charge Voltage (max) (V) 10.5
Battery Charge Current (max) (A) 5
Status Indicator No
Charger Type Switching
Input Source AC Adapter;USB
Features Adjustable Frequency;Adjustable Soft-Start;Built-in Bootstrap Switch;Cycle-by-Cycle Current Limit;Enable Input;I2C;OCP;OVP;Stable with Ceramic Capacitor;UVP
Package Type WL-CSP2.74x2.84-36(BSC)
Built-in Power MOSFETs Yes
  • Integrated Bidirectional Bypass Mode and Cap Divider Mode (DIV2 Mode)
  • Input Reverse Blocking NFET between WRX_IN Pin and VBUS Pin
    ► Block the Reverse Current
  • Dual-Phase Charge Pump Core
    ► 5A Output Current Capability
    ► Efficiency Up to 98.1% when VOUT = 10V, IOUT = 2A, Switching Frequency = 500kHz and Dual Phase with VBUS Input in DIV2 Mode
    ► 300kHz to 1.5MHz Variable Switching Frequency Stay Out of Audio Band
    ► Spread Spectrum Technology for EMI Reduction
    ► Adjustable Single-Phase or Dual-Phase for DIV2 Mode
    ► Programmable Pre-Charge Current and Pre-Charge Timing for Charge Soft-Start
    ► Support Converter Soft-Start with 200mA Loading
  • Support Synchronize Function for Parallel Application
  • Operation Mode Transfer Automatically between Bypass Mode and DIV2 Mode (AT_Function)
  • I2C is Available when Device in Present Mode
  • 3-Error Charge Pump Switch Protection
    ► VBUS Voltage Too Low Error Protection before Switch (VBUS_LOW_ERR)
    ► CFLY Short Error Protection Before Switch (CFLY_DIAG)
    ► Converter Over-Current Protection (CON_OCP)
  • 6-Way System Protection
    ► VBUS Over-Voltage Protection (VBUS_OVP)
    ► IBUS Over-Current Protection (IBUS_OCP)
    ► VOUT Over-Voltage Protection (VOUT_OVP)
    ► WRX Reverse Over-Current Protection (WRX_IRE_OCP)
    ► VOUT Short Error Protection Before Charge (VOUT_ERR)
    ► Junction Over-Temperature Protection (TDIE_OTP)
TitleLast UpdateDownload
High Voltage Smart Cap Divider and Direct Charge Charger2021/07/07
Technical Documents
TitleItem TypeLast UpdateDownload
Richtek Product Selection Guide [Jan., 2024] Selection Guide2024/01/18
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT9758WSCWL-CSP2.74x2.84-36(BSC)3000 Request Buy from Distributor