CH217 USB Current Limiting Power Distribution Switch IC SOT23-6

CH217 USB Current Limiting Power Distribution Switch IC in the compact SOT23-6 package is a crucial component for managing and protecting power in USB host ports and other 5V systems. Acting as a high-side power switch, the CH217 integrates precise current limiting, thermal shutdown, and fault indication. Engineers depend on this IC to prevent damage from short circuits or excessive current draw, ensuring reliable and safe operation of connected peripherals. Its low on-resistance minimizes voltage drop, maximizing power efficiency to the load while maintaining robust system protection.

Key Features:

• Accurate Current Limiting: Precisely controls output current to safe levels, protecting upstream power sources and preventing system resets during overloads.
• Fast Short-Circuit Response: Reacts almost instantly to short-circuit events, disconnecting the load to prevent potential damage.
• Thermal Shutdown: Automatically disables the switch when internal temperature exceeds safe limits, ensuring self-protection of the IC.
• Low Quiescent Current: Consumes minimal power in standby mode, ideal for battery-powered or energy-efficient systems.
• Active-Low Fault Flag Output (OC̅): Notifies the host controller of overcurrent or thermal faults via an open-drain active-low signal.
• Controlled Rise Time: Limits inrush current during power-up by managing output voltage ramp-up behavior.

Technical Specifications:

• Supply Voltage Range (V_IN): 2.7 V – 5.5 V
• Maximum Continuous Current: Model dependent (typically 500 mA or 1 A)
• On-Resistance (R_ON): Typically <100 mΩ
• Fault Response Time: In the microsecond (µs) range
• Current Limit Accuracy: ±10% (typical)
• Package: SOT23-6

Mechanical Specifications:

• Package Type: SOT23-6 (Small Outline Transistor, 6-pin)
• Mounting: Surface Mount Technology (SMT)
• Number of Pins: 6 leads

Dimensions:

• Body Length: Approx. 2.9 mm
• Body Width: Approx. 1.6 mm
• Body Height: Approx. 1.1 mm

Pinout and Wiring:

• V_IN: Power supply input (connects to host V_BUS).
• V_OUT: Switched power output (connects to USB port V_BUS or load).
• GND: Ground reference.
• EN: Enable pin (active high). Drive high to turn ON the switch.
• SET: Current limit adjustment (connect resistor from SET pin to ground to define limit).
• OC̅: Active-low overcurrent flag output. Goes low when fault is detected.
• Wiring Note: Use a 0.1 µF ceramic capacitor between V_IN and GND for decoupling, and a larger capacitor at V_OUT for stability.

Datasheet Reference:

• Download CH217 Datasheet

Commonly Used In:

• PC Motherboards & Laptops: Protects and powers external USB ports.
• USB Hubs: Manages current distribution to ensure each downstream port meets USB specifications.
• Embedded Systems: Protects 5V power rails in microcontroller and SBC applications.

Applications:

• USB Port Protection: Safeguards USB V_BUS against overloads and shorts.
• Hot-Swap Power Management: Enables controlled power connection and disconnection for plug-in modules.
• General High-Side Power Switching: Ideal for current-limited power control in 5V systems.

Equivalent Models:

• TPS20xx Series (Texas Instruments): Widely used USB power switches with similar features.
• MIC20xx Series (Microchip/Micrel): Family of high-side power switches with programmable current limits.
• AP2171 / AP2172 (Diodes Inc.): USB power switch ICs with built-in fault protection.

Package Includes:

• 1 × CH217 USB Current Limiting Power Distribution Switch IC (SOT23-6)