TPS2555DRCT

TPS2554/55 配电开关适用于需要精密电流限制或遇到重电容负载和短路的应用。这些器件通过外部电阻提供介于 500mA 和 2.5A（典型值）之间的可编程电流限制阈值。 当输出负载超出电流限制阈值时，TPS2554/55 器件通过切换到恒定电流模式，将输出电流限制在安全水平。该故障逻辑输出在过流和过温条件下置低。 The TPS2554/55 is a current-limited, power-distribution switch using an internal N-channel MOSFET as a switch for applications where short circuits or heavy-capacitive loads will be encountered. This device allows the user to program two independent current-limit thresholds between 500 mA and 2.5 A (typ) via two external resistors. The ILIM_SEL pin allows the user to select one current limit or the other. This device incorporates an internal charge pump and the gate-drive circuitry necessary to drive the N-channel MOSFET. The charge pump supplies power to the driver circuit and provides the necessary voltage to pull the gate of the MOSFET above the source. The driver controls the gate voltage of the power switch. The TPS2554/55 family limits the output current to the programmed current-limit threshold ILIM0 or lLIM1 during an overcurrent or short-circuit event by reducing the charge-pump voltage driving the N-channel MOSFET and operating it in the linear range of operation. This necessarily results in a reduction in the output voltage at OUT. Exposure to an overload condition leads directly to heat dissipation in the internal MOSFET. The MOSFET is protected thermally such that it will shut off when it gets too hot. The TPS2554/55 will automatically restart following cooling of the device.

Applications

• USB ports/hubs
• Digital TV
• Set-top boxes
• VoIP phones

Key features

• Meets USB current limiting requirements
• Adjustable current limit, 500mA to 2.5A (typical)
• Two independently configurable current limit thresholds
• Fast overcurrent response — 1.5μs (typical)
• 73mΩ high-side MOSFET
• 3.8A maximum quiescent supply current
• PowerPAD thermal management
• Automatic output discharge when disabled
• Available in active-high enable (TPS2554) and active-low enable (TPS2555) versions