80mΩ, 500mA/1.1A High Side Power Switches with Flag


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The RT9702 and RT9702A are cost-effective, low voltage, single N-Channel MOSFET high-side power switches, optimized for self-powered and bus- powered Universal Serial Bus (USB) applications. The RT9702/A equipped with a charge pump circuitry to drive the internal MOSFET switch; the switch's low RDS(ON), 80mΩ, meets USB voltage drop requirements; and a flag output is available to indicate fault conditions to the local USB controller.
Additional features include soft-start to limit inrush current during plug-in, thermal shutdown to prevent catastrophic switch failure from high current loads, under-voltage lockout (UVLO) to ensure that the device remains off unless there is a valid input voltage present, fault current is limited to typically 800mA for RT9702 in single port and 1.5A for RT9702A in dual ports in accordance with the USB power requirements, lower quiescent current as 25μA making this device ideal for portable battery-operated equipment.
The RT9702/A is available in SOT-23-5 and TSOT-23-5 packages requiring minimum board space and smallest components.


  • USB Bus/Self Powered Hubs
  • USB Peripherals
  • ACPI Power Distribution
  • PC Card Hot Swap
  • Notebook, Motherboard PCs
  • Battery-Powered Equipment
  • Hot-Plug Power Supplies
  • Battery-Charger Circuits
Key Spec.
RT9702 RT9702A
Status Obsolete Obsolete
Recommended Alternative  RT9742
Number of Outputs 1 1
Vin (min) (V) 2 2
Vin (max) (V) 5.5 5.5
Ron (typ) (mOhm) 80 80
Iq (typ) (mA) 0.025 0.025
Current Limit (typ) (A) 0.8 1.5
FLAG Indicator Yes Yes
Iocp Adjustable No No
Safety UL UL
Features Cycle-by-Cycle Current Limit;Enable Input;SCP Cycle-by-Cycle Current Limit;Enable Input;SCP
Package Type SOT-25;TSOT-25 SOT-25;TSOT-25
  • Compliant to USB Specifications
  • Built-In (Typically 80mΩ) N-Channel MOSFET
  • Output Can Be Forced Higher Than Input (Off-State)
  • Low Supply Current :
      ♦ 25μA Typical at Switch On State
      ♦ 1μA Typical at Switch Off State
  • Guaranteed 500mA/RT9702 and 1.1A/RT9702A Continuous Load Current
  • Wide Input Voltage Ranges : 2V to 5.5V
  • Open-Drain Fault Flag Output
  • Hot Plug-In Application (Soft-Start)
  • 1.7V Typical Under Voltage Lockout (UVLO)
  • Current Limiting Protection
  • Thermal Shutdown Protection
  • Reverse Current Flow Blocking (no body diode)
  • Smallest SOT-23-5 and TSOT-23-5 Packages Minimizes Board Space
  • UL Approved-E219878
  • TUV IEC60950-1 : 2005 Certified
  • RoHS Compliant and 100% Lead (Pb)-Free
Technical Documents
TitleLast UpdateShareDownload
The Reduction of Input Voltage Spike on Power Switches2016/04/08