Datasheet
Table Of Contents
- 1.0 Introduction
- 2.0 USB3320 Pin Locations and Definitions
- 3.0 Limiting Values
- 4.0 Electrical Characteristics
- 4.1 Operating Current
- 4.2 Clock Specifications
- 4.3 ULPI Interface Timing
- 4.4 Digital IO Pins
- 4.5 DC Characteristics: Analog I/O Pins
- 4.6 Dynamic Characteristics: Analog I/O Pins
- 4.7 OTG Electrical Characteristics
- 4.8 USB Audio Switch Characteristics
- 4.9 Regulator Output Voltages and Capacitor Requirement
- 4.10 Piezoelectric Resonator for Internal Oscillator
- 5.0 Architecture Overview
- FIGURE 5-1: USB3320 Internal Block Diagram
- 5.1 ULPI Digital Operation and Interface
- 5.2 USB 2.0 Hi-Speed Transceiver
- 5.3 Bias Generator
- 5.4 Integrated Low Jitter PLL
- 5.5 Internal Regulators and POR
- 5.6 USB On-The-Go (OTG)
- 5.7 USB UART Support
- 5.8 USB Charger Detection Support
- 5.9 USB Audio Support
- 5.10 Reference Frequency Selection
- 6.0 ULPI Operation
- 6.1 Overview
- 6.2 ULPI Register Access
- 6.3 Low Power Mode
- 6.4 Full Speed/Low Speed Serial Modes
- 6.5 Carkit Mode
- 6.6 RID Converter Operation
- 6.7 Headset Audio Mode
- 7.0 ULPI Register Map
- 8.0 Application Notes
- 8.1 Application Diagram
- TABLE 8-1: Component Values in Application Diagrams
- TABLE 8-2: Capacitance Values at VBUS of USB Connector
- FIGURE 8-1: USB3320 Application Diagram (Device, ULPI Output Clock mode, 24MHz)
- FIGURE 8-2: USB3320 Application Diagram (Device, ULPI Input Clock mode, 60MHz)
- FIGURE 8-3: USB3320 Application Diagram (Host or OTG, ULPI Output Clock Mode, 24MHz)
- 8.2 Reference Designs
- 8.3 ESD Performance
- 8.1 Application Diagram
- 9.0 Package Information
- Appendix A: Data Sheet Revision History
- The Microchip Web Site
- Customer Change Notification Service
- Customer Support
- Product Identification System
- Worldwide Sales and Service
USB3320
DS00001792E-page 26 2014-2016 Microchip Technology Inc.
5.6 USB On-The-Go (OTG)
The USB3320 provides full support for USB OTG protocol. OTG allows the USB3320 to be dynamically configured as
a host or device depending on the type of cable inserted into the receptacle. When the Micro-A plug of a cable is inserted
into the Micro-AB receptacle, the USB device becomes the A-device. When a Micro-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 “On-The-Go Supplement to the USB 2.0 Specification”. In applications where only
Host or Device is required, the OTG Module is unused.
5.6.1 ID RESISTOR DETECTION
The ID pin of the USB connector is monitored by the ID pin of the USB3320 to detect the attachment of different types
of USB devices and cables. For device only applications that do not use the ID signal the ID pin should be connected
to VDD33. The block diagram of the ID detection circuitry is shown in Figure 5-10 and the related parameters are given
in Table 4-7.
5.6.1.1 USB OTG Operation
The USB3320 can detect ID grounded and ID floating to determine if an A or B cable has been inserted. The A plug will
ground the ID pin while the B plug will float the ID pin. These are the only two valid states allowed in the OTG Protocol.
To monitor the status of the ID pin, the Link activates the IdPullup bit in the OTG Control register, waits 50mS and then
reads the status of the IdGnd bit in the USB Interrupt Status register. If an A cable has been inserted the IdGnd bit will
read 0. If a B cable is inserted, the ID pin is floating and the IdGnd bit will read 1.
The USB3320 provides an integrated weak pull-up resistor on the ID pin, R
IDW
. This resistor is present to keep the ID
pin in a known state when the IdPullup bit is disabled and the ID pin is floated. In addition to keeping the ID pin in a
known state, it enables the USB3320 to generate an interrupt to inform the link when a cable with a resistor to ground
has been attached to the ID pin. The weak pull-up is small enough that the largest valid Rid resistor pulls the ID pin low
and causes the IdGnd comparator to go low.
After the link has detected an ID pin state change, the RID converter can be used to determine the resistor value as
described in Section 5.6.1.2.
FIGURE 5-10: USB3320 ID RESISTOR DETECTION CIRCUITRY
IdPullup
IdGnd
V
ref
IdGnd
R
ID
=100K
R
IDW
>1M
IdFloat
ID
~
~
~
~
OTG Module
VDD33
To USB Con.
RidValue
V
ref
IdFloat
IdGnd Rise or
IdGnd Fall
IdFloatRise or
IdFloatFall
Rid ADC
IdGndDrv
en
en