SI3462-EVB Datasheet, PDF (1/32 Pages) Silicon Laboratories – EVALUATION BOARD USERS GUIDE

Si3462-EVB
Si3462 EVALUATION BOARD USER’S GUIDE
1. Introduction
This document is intended to be used in conjunction with the Si3462 data sheet for designers interested in the
following:
An introduction to Power over Ethernet (PoE) and Power Sourcing Equipment (PSE) design considerations
Operation of the Si3462 PSE controller in the Si3462-EVB reference design
Configuration and operation of the Si3462-EVB
2. Overview of the Si3462 and Evaluation Board
The Si3462 is a single-port power management controller for IEEE 802.3at PoE/PoE+ compliant Power Sourcing
Equipment (PSE). The Si3462 operates directly from a 50 V (nominal) isolated input for PoE or 54 V (nominal)
isolated input for PoE+. The complete Si3462 reference design (i.e., the Si3462-EVB) also provides full
IEEE-compliant classification and detection as well as a robust disconnect algorithm. Intelligent protection circuitry
includes input under-voltage and over-voltage lockout (UVLO/OVLO), current limiting, and output short-circuit
protection.
The Si3462 is designed to operate completely independently of host processor control. A reset button and an
optional LED status signal are provided to indicate port status including detect, power good, and output fault event
information.
The Si3462 is pin-programmable to support:
No classification mode reduces bill of materials for 15.4 W operation and also for non-standard powered
devices that do not present a proper classification signature
Endpoint and midspan applications with support for either 10/100BASE-T or 10/100/1000BASE-T
All PoE/PoE+ classification power levels
Classification-based current limiting
Automatic or manual restart after various fault events are detected
V_IN
+50 V
V_DD
+3.3 V
GND
+50 V
Optional 3.3 V regulator
RST
GND
VDD
CLSMARK
DC1
DC2
Si3462 ^CLSMODE
DETA
VSENSE
ISENSE
STATUS
GND
DETECT
FAULT
PGOOD
Classification
&
Gate drive
Detect
&
Mark
Figure 1. Typical Application Circuit
(Example is for PoE; for PoE+, use +54 V nominal V_IN)
+
V_OUT
48 V
PSE
output
(to port
magnetics)
_
Rev. 1.2 1/15
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Si3462-EVB