USB3300 SMSC Corporation, USB3300 Datasheet - Page 41

• Manufacturer Part Number: USB3300
• Description: Hi-Speed USB Host
• Manufacturer: SMSC Corporation

Hi-Speed USB Host, Device or OTG PHY with ULPI Low Pin Interface
Datasheet
SMSC USB3300
6.4.1
6.4.2
6.5
Internal Regulators
The USB3300 has two internal regulators that create two 1.8V outputs (labeled VDD1.8 and VDDA1.8)
from the 3.3volt power supply input (VDD3.3). Each regulator requires an external 4.7uF +/-20% low
ESR bypass capacitor to ensure stability. X5R or X7R ceramic capacitors are recommended since they
exhibit an ESR lower that 0.1ohm at frequencies greater than 10kHz.
Note: The specific capacitor recommendations for each pin are detailed in
Power On Reset (POR)
The USB3300 provides an internal POR circuit that generates a reset pulse once the PHY supplies
are stable. This reset will set all of the ULPI registers to their default values and start the PHY in normal
operation. Cycling the 3.3 volt power supply is the only method for the PHY to reset the ULPI registers
to their default states. The Link can write the registers to their default states at any time in normal
operation.
The RESET pin has the same functionality as the RESET register in the Function Control Register.
The USB3300 provides support for USB OTG. OTG allows the USB3300 to be dynamically configured
as a host or a device depending on the type of cable inserted into the Mini-AB connector. When the
Mini-A plug of a cable is inserted into the Mini-AB connector, the USB device becomes the A-device.
When a Mini-B plug is inserted, the device becomes the B-device. The OTG A-device behaves similar
to a Host while the B-device behaves similar to a peripheral. The differences are covered in the OTG
supplement.
The OTG Module meets all the requirements in the “On-The-Go Supplement to the USB 2.0
Specification”. In applications where only Host or Device is required, the OTG Module is unused.
USB On-The-Go (OTG) Module
Figure 7.1 on page
the USB3300 only. Using the regulators to provide current for other circuits is not
recommended and SMSC does not guarantee USB performance or regulator stability.
46. The USB3300 regulators are designed to generate a 1.8 volt supply for
DATASHEET
41
Table
Revision 1.06 (07-19-06)
3.1, and shown in