Rev. 0.82 4/09 Copyright © 2009 by Silicon Laboratories Si3400/1/2-EVB
Si3400/1/2-EVB
NON-ISOLATED EVALUATION BOARD FOR THE Si3400,
Si3401,
AND Si3402
1. Description
The Si3400, Si3401, and Si3402 non-isolated evaluation board (Si3400/1/2-EVB Rev 1.41) are reference designs
for a power supply in a Power over Ethernet (PoE) Powered Device (PD) application. The Si3400, Si3401, and
Si3402 are described more completely in the data sheet and application notes. This document describes the
evaluation board. An evaluation board demonstrating the isolated application is described in the
Si3400/1/2ISO-EVB user’s guide.
2. Si3400/1/2 Board Interface
Ethernet data and power are applied to the board through the RJ-45 connector (J1). The board may be powered by
the following:
Connecting a dc source to 1, 2 and 3, 4 (either polarity)
Connecting a dc source to 4, 5 and 7, 8 (either polarity)
Using an 802.3af-compliant PSE such as Phihong PSA16U-480 (PoE)
The board itself has no Ethernet data transmission functionality, but, as a convenience, the Ethernet transformer
secondary is brought out to the test points. The dc output is at connectors J4(+) and J3(–).
Boards are generally shipped configured to produce +5 V but can be configured for +3.3 V or other output voltages
by changing resistors R5 and R6. Refer to “AN296: Using the Si3400 and Si3401 PoE PD Controllers in Isolated
and Non-Isolated Designs” and its accompanying Excel
®
spreadsheet utility for more information. The only other
test point provided is J6, which is the power loss (PLOSS
) indicator.
3. Schematics
The Si3400/1/2-EVB board schematics and layers are shown in Figures 1 through 6. The evaluation boards for the
Si3400, Si3401, and Si3402 are essentially identical. The only differences are that the diode bridges are bypassed
(populated); the PD controller on the Si3401-EVB is the Si3401; and the PD controller on the Si3402-EVB is the
Si3402.
