DC1335B-B

DC1335B-B demonstration circuit is a high-power supply featuring the LTC®4269-1. This board acts as an IEEE 802.3at compliant, high power, power-over-Ethernet (PoE), Powered Device (PD) and connects at the RJ45 to a compatible high power, power Sourcing Equipment (PSE) device, such as the DC1366. The LTC4269-1 provides IEEE 802.3at standard (PoE+) PD interfacing and power supply control. When the PD is fully powered, the PD interface switches power over from the PSE to the switcher through an internal, low resistance, high power MOSFET. The highly integrated LTC4269-1 controls a high-power, small-sized power supply that utilizes a highly efficient isolated flyback topology with synchronous rectification. The DC1335B-B supplies a 5V output at up to 4.5A. DC1335B-B also demonstrates the use of an auxiliary 48V wall adapter. When present, the auxiliary supply becomes the dominant supply over PoE to provide power.

• Port voltage (VPORT) range from 37V to 57V, auxiliary voltage (VAUX) range from 44V to 57V
• 5V output voltage
• 4.5A maximum output current (VPORT = 42V)
• 40mVP–P (typ) typical output voltage ripple (VIN = 50V, IOUT = 4.6A)
• 250kHz (typ) switching frequency