Iei-integration ICE-DB-T6 Manual do Utilizador descarregar pdf (Página 50)

Type 6 Carrier Board Design Guide

Page 40

3.4.4 Over Current Protection

Over-current protection for USB ports can be implemented by using power distribution

switches on the carrier board that monitor the USB port power lines. Power distribution

switches usually have a soft-start circuitry that minimizes inrush current in applications

where highly capacitive loads are employed. Transient faults are internally filtered.

Additionally, they offer a fault status output that is asserted during over-current and

thermal shutdown conditions. These outputs should be connected to the corresponding

COM Express modules USB over-current sense signals. IEI uses MIC2026 for carrier

board.

Figure 3-17: MIC2026 Block Diagram (Please refer the datasheet from MICREL )

3.4.5 Reference Schematics

The following notes apply to Figure 3-18 below.

LAN_USB and CN26 incorporate two USB Type A receptacles, LAN_USB in addition

includes an RJ-45 (LANKom LJ -G40BU1-10-F).

The reference design uses an over-current detection and protection device. The Micrel

MIC2026 is dual channel power distribution switch. Power to the USB Port is filtered using

a ferrite (30 Ω @100MHz, 600mA) to minimize emissions. The ferrite should be placed

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