SMSC USB2512i Chapter 3 Pin Descriptions, 3.1PIN Descriptions, EMB, TYPE, QFN-36, BUFFER, SYMBOL, DESCRIPTION, UPSTREAM USB INTERFACES, DOWNSTREAM 2-PORTUSB 2.0 INTERFACE

Industrial Temperature Rated USB 2.0 High-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 USB2512i Pin Descriptions

	QFN-36		BUFFER
SYMBOL	EMB		TYPE	DESCRIPTION
			UPSTREAM USB INTERFACES
USBUP_DP	31		IO-U	USB Bus Data
USBUP_DM	30			These pins connect to the upstream USB bus data signals
				(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 (signaling 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 of 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_DP[2:1]/	4		IO-U	High-Speed USB Data
&	2			These pins connect to the downstream USB peripheral devices
	3			attached to the hub’s port.
USBDN_DM[2:1]/	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}
RBIAS	35		I-R	USB Transceiver Bias
				A 12.0kΩ (+/- 1%) resistor is attached from ground to this pin
				to set the transceiver’s internal bias settings.

Revision 1.92 (11-28-07)	8	SMSC USB2512i
	DATASHEET