TPS2372-4EVM-006: Evaluation Module for IEEE802.3bt PoE PD Applications

The TPS2372-4EVM-006 enables full evaluation of the TPS2372-4 device. Ethernet power is applied from J1 and is dropped to the FET bridge rectifier. At the output of the FET Bridge is the EMI/EMC filter and transient protection for the TPS2372-4. Input power can also be applied at J3 from a DC source when power at J1 is not present. The TPS2372-4 (U1) PD controllers is shown in Figure 1. R23 provides the detection signature. To the right of U2 is the switched side of the PD controller. The TPS2372-4 RTN pin provides inrush limited turn on and the charge of the bulk capacitor C11.

The TPS2372-4 contains all of the features needed to implement an IEEE802.3bt (draft) (Type 1-4) powered device (PD). The low internal switch resistance allows the TPS2372-4 to support high power applications up to 90 W. Assuming 100-meter CAT5 cable, this translates into 71.3 W at PD input.

The TPS2372 operates with enhanced features. The Automatic MPS function enables applications requiring very low power standby modes. The TPS2372 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.

The TPS2372 also implements a delay function to allow the remote PSE to complete its inrush phase before releasing the Power Good (PG) output. This ensures that the IEEE802.3bt (draft) startup requirements are met. The Autoclass enable input also allows advanced system power optimization modes compliant with IEEE802.3bt (draft) standard.