TPS2371DR

Specialized Overview

The TPS2371DR is a legacy IEEE 802.3af compatible power interface switch for Powered Devices (PDs), manufactured by Texas Instruments in an 8-pin SOIC package. It operates within an input voltage range of 44 V to 57 V and supports an operating temperature of 0°C to 70°C. The device features an internal 0.3-Ω low-side FET, programmable inrush current limiting ranging from 50 mA to 449 mA, and precision UVLO thresholds with a 20-ms off-time delay. It provides PD detection and classification signatures (Class 0–4) and interfaces directly with DC/DC converter soft-start circuits.

Specialized Feature Summary

• Performs complete detection, classification, and inrush current limiting for IEEE 802.3af PoE compatibility
• Integrates a low-side FET that activates at 36 V and disconnects during thermal shutdown events
• Interfaces with DC/DC converters via the EN_DC pin to manage soft-start timing

Specialized Applications

• VoIP Phones
• Internet Appliances
• Wireless LAN Access Points
• Bluetooth Access Points

Specialized Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm the exact tape-and-reel quantity and lead finish specifications. Confirm the operational temperature range aligns with your system requirements before finalizing procurement orders.

Specialized Selection Notes

Select this component when designing a Powered Device requiring strict compliance with legacy IEEE 802.3af standards. Ensure the external load capacitance does not exceed limits without utilizing the programmable inrush current feature on the ILIM pin to maintain protocol compliance.

Specialized Part Context

This part belongs to the TPS237x family of Power Interface Switches designed specifically for Powered Devices. It serves as the primary front-end controller for managing power acquisition over Ethernet cabling, handling the handshake protocols between the Power Sourcing Equipment and the end appliance.

Specialized Replacement Considerations

Public confirmed substitute part numbers include TPS2371D, TPS2371PW, and TPS2371PWR. Verify package type and thermal characteristics when substituting between SOIC and TSSOP variants.

Specialized FAQ

How is the inrush current limit programmed?

The inrush current is set by connecting an external resistor (RLIM) from the ILIM pin to the VEE pin, allowing a programmable range from 50 mA to 449 mA.

What is the function of the EN_DC pin?

The EN_DC pin acts as a control output for the connected DC/DC converter, sinking 80 µA to hold the converter off until the load capacitor charges sufficiently.

How does the device handle overload conditions?

In the event of a short circuit or overload, the device enters thermal shutdown, switching off the internal FET. It retries automatically but will latch off after seven cycles if the fault persists.