DEMO MANUAL DC1815A LTC4266A ++ Quad LTPoE PSE Controller DESCRIPTION 2 Demonstration circuit 1815A features the LTC 4266A quad an I C serial interface operable up to 1MHz. Optional 2 power sourcing equipment (PSE) controller, capable of I C control is accessed on the DC1815A either with test ++ delivering up to 90W of LTPoE power to a compatible points or a 14-pin ribbon cable for DC590 QuikEval GUI ++ LTPoE powered device (PD). A proprietary detection/ operation. classification scheme allows mutual identification between The LTC4266A is configurable on the DC1815A as an AUTO ++ ++ an LTPoE PSE and LTPoE PD while remaining com- pin high, MID pin high, autonomous midspan power injec- patible and interoperable with existing Type 1 (13W) and tor input data from an existing network system is sent out, Type2 (25.5W) PDs. The LTC4266A feature set is a superset along with power, to a PD. The LTC4266A autonomously of the popular LTC4266. These PSE controllers utilize low detects a PD, turns power on to the port, and discon- R external MOSFETs and 0.25 sense resistors which ON nects port power without the need for a microcontroller. ++ are especially important at the LTPoE current levels to OUTn LEDs indicate that port power is present. A single maintain the lowest possible heat dissipation. 55V supply is required to power the DC1815A. A simple The LTC4266A is available in multiple power grades, allow- LDO regulator circuit on the board powers the digital sup- ing delivered PD power of 13W, 25.5W, 38.7W, 52.7W, 70W ply of the LTC4266A. A SHDN pushbutton for each port and 90W. The DC1815A has four variations DC1815A-A, shuts down the respective port and disables detection. DC1815A-B, DC1815A-C, and DC1815A-D which accom- Pre-programmed masked shutdown ports are shut down ++ modate the four LTPoE power levels (Table 1). with the MSD pushbutton. A RESET pushbutton resets the LTC4266A to its AUTO pin logic state. Ports shut down Advanced power management features of the LTC4266A with the SHDN or MSD pushbutton must be re-enabled include: a 14-bit current monitoring ADC, DAC-program- 2 via I C or a device reset with the AUTO pin high. mable current limit, and versatile quick port shutdown. Advanced power management host software is available Design files for this circuit board are available at under a no-cost license. PD discovery uses a proprietary DEMO MANUAL DC1815A QUICK START PROCEDURE Demonstration circuit 1815A is easy to set up for evaluat- 4. Connect with an Ethernet cable an 802.3at Type 1 or ++ ing the performance of the LTC4266A. Refer to Figure 1 Type 2, or LTPoE compatible PD to one of the four for proper test equipment setup and follow the procedure bottom ports of 2x4, RJ45 connector J1. below. 5. (Optional) For data tests, connect a PHY with an 1. Set MID jumper JP5 to LO which disables midspan Ethernet cable to one of the four top ports of 2x4, RJ45 mode. connector J1. 2. Set AUTO jumper JP4 to HI which enables AUTO pin 6. (Optional) Connect a DC590 via ribbon cable to the high mode. DC1814A and via USB to a PC. Open the QuikEval 2 software for I C GUI interfacing. 3. Connect a 55V to 57V power supply across AGND (+) and VEE (). Size the power supply considering the maximum power delivered to the PDs. Figure 1. DC1815A Setup dc1815afd 2