USB3300_07 datasheet(41/55 Pages) SMSC

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Hi-Speed USB Host, Device or OTG PHY with ULPI Low Pin Interface

Datasheet

SMSC USB3300

Revision 1.08 (11-07-07)

DATASHEET

6.4

Internal Regulators and POR

The USB3300 includes an integrated set of built in power management functions, including a POR

generator. Internal regulators enable the USB3300 to be powered from a single 3.3 volt power supply,

thereby reducing the bill of materials and simplifying product design.

6.4.1

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 Table 3.1, "USB3300 Pin

Definitions 32-Pin QFN Package", and shown in Figure 7.1 USB3300 Application Diagram

(Peripheral)on page 47. The USB3300 regulators are designed to generate a 1.8 volt supply

for 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.

6.4.2

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.

6.5

USB On-The-Go (OTG) Module

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.

USB3300 Datasheet(PDF) 41 Page - SMSC Corporation