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 30 2014-2016 Microchip Technology Inc.
5.6.2.6 VBUS Overvoltage Protection
The USB3320 provides an integrated overvoltage protection circuit to protect the VBUS pin from excessive voltages
that may be present at the USB connector. The overvoltage protection circuit works with an external resistor (R
VBUS
) by
drawing current across the resistor to reduce the voltage at the VBUS pin.
When voltage at the VBUS pin exceeds 5.5V, the Overvoltage Protection block will sink current to ground until VBUS is
below 5.5V. The current drops the excess voltage across R
VBUS
and protects the USB3320 VBUS pin. The required
R
VBUS
value is dependent on the operating mode of the USB3320 as shown in Table 5-7.
The Overvoltage Protection circuit is designed to protect the USB3320 from continuous voltages up to 30V on the R
VBUS
resistor.
The R
VBUS
resistor must be sized to handle the power dissipated across the resistor. The resistor power can be found
using the equation below:
For example, protecting a peripheral or device only application to 15V would require a 10kΩ R
VBUS
resistor with a power
rating of 0.01W. To protect an OTG product to 15V would require a 1kΩ R
VBUS
resistor with a power rating of 0.1W.
5.6.3 DRIVING EXTERNAL VBUS
The USB3320 monitors VBUS as described in VBUS Monitor and Pulsing. For OTG and Host applications, the system
is required to source 5 volts on VBUS. The USB3320 fully supports VBUS power control using an external VBUS switch
as shown in Figure 8-3. The USB3320 provides an active high control signal, CPEN, that is dedicated to controlling the
Vbus supply when configured as an A-Device.
CPEN is asserted by setting the DrvVbus or DrvVbusExternal bit of the OTG Control register. To be compatible with Link
designs that support both internal and external Vbus supplies the DrvVbus and DrvVbusExternal bits in the OTG Control
Register are or’d together. This enables the Link to set either bit to access the external Vbus enable (CPEN). This logic
is shown in Figure 5-12. DrvVbus and DrvVbusExternal are set to 0 on Power On Reset (POR) as shown in
Section 7.1.1.7.
TABLE 5-7: REQUIRED R
VBUS
RESISTOR VALUE
Operating Mode R
VBUS
Device only 10kΩ ±5%
OTG Capable 1kΩ ±5%
Host
UseExternalVbusIndicator = 1
10kΩ ±5%
P
RVBUS
Vprotect 5.0–
2
R
VBUS
------------------------------------------- -
=
Where:
• Vprotect is the VBUS protection required
•R
VBUS
is the resistor value, 1kΩ or 10kΩ.
•P
RVBUS
is the required power rating of R
VBUS