Industrial Temperature Rated USB 2.0 Hi-Speed 2-Port Hub Controller

Datasheet

Chapter 3 Pin Descriptions

3.1Pin Descriptions

This section provides a detailed description of each signal. The signals are arranged in functional groups according to their associated interface.

The “N” symbol in the signal name indicates that the active, or asserted, state occurs when the signal is at a low voltage level. When “N” is not present before the signal name, the signal is asserted when at the high voltage level.

The terms assertion and negation are used exclusively. This is done to avoid confusion when working with a mixture of “active low” and “active high” signals. The term assert, or assertion, indicates that a signal is active, independent of whether that level is represented by a high or low voltage. The term negate, or negation, indicates that a signal is inactive.

Table 3.1 USB2512Ai Pin Descriptions

 

QFN-36

 

BUFFER

 

SYMBOLEMB

 

TYPEDESCRIPTION

 

 

 

 

 

 

 

 

UPSTREAM USB INTERFACES

 

 

 

 

 

USBUP_DP

31

 

IO-U

USB Bus Data

USBUP_DM

30

 

 

These pins connect to the upstream USB bus data signals such

 

 

 

 

 

 

 

 

as the Host port or upstream Hub.

 

 

 

 

 

VBUS_DET

27

 

I/O12

Detect Upstream VBUS Power

 

 

 

 

Detects state of Upstream VBUS power. The SMSC Hub

 

 

 

 

monitors VBUS_DET to determine when to assert the internal

 

 

 

 

D+ pull-up resistor which signals a connect event.

 

 

 

 

When designing a detachable Hub, this pin must be connected

 

 

 

 

to the VBUS power pin of the USB port that is upstream from

 

 

 

 

the Hub.

 

 

 

 

For self-powered applications with a permanently attached

 

 

 

 

host, this pin must be connected to 3.3V (typically VDD33).

 

 

 

 

 

 

 

DOWNSTREAM 2-PORT USB 2.0 INTERFACE

 

 

 

 

 

USBDN[2:1]_DP/

4

 

IO-U

Hi-Speed USB Data

&

2

 

 

These pins connect to the downstream USB peripheral devices

 

 

 

 

 

 

 

3

 

 

attached to the Hub’s port.

USBDN[2:1]_DM/

1

 

 

 

 

 

 

 

 

PRTPWR[2:1]

16

 

O12

USB Power Enable

 

12

 

 

Enables power to USB peripheral devices downstream.

 

 

 

 

 

 

 

 

Note: The Hub supports active high power controllers only!

 

 

 

 

 

OCS[2:1]_N

17

 

IPU

Over-Current Sense

 

13

 

 

Input from external current monitor indicating an over-current

 

 

 

 

 

 

 

 

condition.

 

 

 

 

{Note: Contains internal pull-up to 3.3V supply}

 

 

 

 

 

Revision 1.97 (08-11-08)

8

SMSC USB2512Ai

 

DATASHEET