LAN9512I-JZX Standard Microsystems (SMSC), LAN9512I-JZX Datasheet - Page 16

• Manufacturer Part Number: LAN9512I-JZX
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LAN9512I-JZX

• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6V
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 64
• Lead Free Status / RoHS Status: Supplier Unconfirmed

Revision 1.0 (11-24-09)
2.1
2.1.1
Port Power Control
This section details the usage of the port power control pins PRTCTL[3:2].
Port Power Control Using a USB Power Switch
The LAN9512/LAN9512i has a single port power control and over-current sense signal for each
downstream port. When disabling port power the driver will actively drive a ‘0’. To avoid unnecessary
power dissipation, the internal pull-up resistor will be disabled at that time. When port power is enabled,
the output driver is disabled and the pull-up resistor is enabled, creating an open drain output. If there
is an over-current situation, the USB Power Switch will assert the open drain OCS signal. The schmitt
trigger input will recognize this situation as a low. The open drain output does not interfere. The
overcurrent sense filter handles the transient conditions, such as low voltage, while the device is
powering up.
Figure 2.2 Port Power Control with USB Power Switch
LAN9512/
LAN9512i
DATASHEET
PRTCTL3
PRTCTL2
16
EN
EN
OCS
OCS
USB Power
USB Power
USB 2.0 Hub and 10/100 Ethernet Controller
Switch
Switch
Device
Device
USB
USB
5V
5V
SMSC LAN9512/LAN9512i
Datasheet