SI3402-EVB Datasheet, PDF (1/14 Pages) Silicon Laboratories – NON-ISOLATED EVALUATION BOARD

Si3402-EVB
NON-ISOLATED EVALUATION BOARD FOR THE Si3402
1. Description
The Si3402 non-isolated evaluation board (Si3402-EVB Rev 1.41) is a reference design for a power supply in a
Power over Ethernet (PoE) Powered Device (PD) application. The Si3402 is 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 Si3402ISO-EVB user’s guide.
2. Si3402 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 Si3400/1/2 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 Si3402-EVB board schematics and layers are shown in Figures 1 through 6. The Si3402-EVB is normally
populated for 5 V output, Class 3 signature, and without the diode bridge bypass recommended for higher power
levels. Use the ordering option Si3402-C4-EVB for 5 V output, Class 4 signature, and diode bridge bypass for
higher power levels.
Rev. 1.0 1/15
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Si3402-EVB