MIC2551A-2.5(2006) Ver la hoja de datos (PDF) - Micrel

Número de pieza

componentes Descripción

Fabricante

MIC2551A-2.5
(Rev.:2006)

USB Transceiver

Micrel 

MIC2551A-2.5

Functional Diagram

VIF

CON

SPD

OE#

RCV

VP

VM

SUS

To Internal

Circuitry

LDO

Regulator

VBUS

VTERM

VPU

D+

D–

GND

MIC2551A

Micrel, Inc.

Applications Information

The MIC2551A is designed to provide USB connectivity in

mobile systems where available system supply voltages are

not able to satisfy USB requirements. The MIC2551A can

operate interface supply voltages as low as 1.6V and still

meet the USB physical layer specifications. As shown in the

circuit above, the MIC2551A takes advantage of the USB

supply voltage, VBUS, to operate the transceiver. The system

voltage, VIF, is used to set the reference voltage used by the

digital I/O lines interfacing to the system controller. Internal

circuitry provides translation between the USB and system

voltage domains. VIF will typically be the main supply voltage

rail for the controller.

In addition, a 3.3V, 10% termination supply voltage, (VPU),

is provided to support speed selection. VPU can be disabled

or enabled under software control via the CON input. This

allows for software-controlled connect or disconnect states.

A 1.5k resistor is required to be connected between this pin

and the D+ or D– lines to respectively specify high speed or

low speed operation.

March 2006

7

M9999-031306

Share Link: