High-Power PoE PD Interface with Advanced Startup

High-Power PoE PD Interface with Advanced Startup - TPS2373


The TPS2373 contains all of the features needed to implement an IEEE802.3at or IEEE802.3bt (draft) (Type 1-4) powered device (PD). The low internal switch resistance allows the TPS2373-4 and TPS2373-3 to support high power applications up to 90 W and 60 W respectively. Assuming 100-meter CAT5 cable, this translates into 71.3 W and 51 W at PD input.

The TPS2373 operates with enhanced features.

The Advanced Startup function for DC-DC results in a simple, flexible, and minimal system cost solution, while ensuring that IEEE802.3bt (draft) startup requirements are met. It helps to reduce the size of the low voltage bias capacitor considerably. It also allows long DC-DC converter soft-start period and enables the use of a low-voltage PWM controller.

The Automatic MPS function enables applications requiring very low power standby modes. The TPS2373 automatically generates the necessary pulsed current to maintain the PSE power. An external resistor is used to enable this functionality and to program the MPS pulsed current amplitude.


  • IEEE 802.3bt (Draft) PD Solution for Type 3 or Type 4 PoE
  • Supports Power Levels for Type-4 ( TPS2373-4) 90-W and Type-3 ( TPS2373-3) 60-W Operation
  • Robust 100 V Hotswap MOSFET
    • TPS2373-4 (typ.): 0.1-Ω, 2.2-A Current Limit
    • TPS2373-3 (typ.): 0.3-Ω, 1.8-A Current Limit
  • Allocated Power Indicator Outputs
  • Advanced Startup for DC-DC
    • Simplifies Downstream DC-DC Design
    • Compliant to PSE Inrush
  • Automatic Maintain Power Signature (MPS)
    • Auto-adjust MPS for Type 1-2 or 3-4 PSE
    • Supports Ultra-Low Power Standby Modes
  • Primary Adapter Priority Input
  • Supports PoE++ PSE
  • -40°C to 125°C Junction Temperature Range
  • 20-lead VQFN Package

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Parametrics Compare all products in Powered Device

Vin (Min) (V)
Vin (Max) (V)
PoE Current Limit (Min) (mA)
PoE Inrush Limit (Typ) (mA)
rDS(on) per FET (Typ) (mOhms)
PoE Standards Supported
PD Power Level
DC/DC Control
Package Group
Package Size: mm2:W x L (PKG)
335mA Typ   
802.3bt Type 4   
PD Only   
Adapter priority
Advanced startup
Auto-adjust MPS
Non-standard POE++ compatible
Thermal Shutdown   
20VQFN: 25 mm2: 5 x 5(VQFN)   
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