The USB standards propose routing guidelines for high-speed USB platforms in the High Speed USB Platform Design Guidelines document available on the USB-IF website.
Note:
For a full-speed driver that is part of a high-speed driver, the impedance is 45 Ω ± 10%.
Recommendations:
Because the ULPI PHY is the controller of an ULPI CLK, a crystal oscillator is required to guarantee clock precision for the ULPI sampling and for the USB HS data sampling.
The OTG specification requires a capacitor (maximum value 4.7 μF) on VBUS.
The ESD protection chip, if used, has to be placed as close as possible to the USB connector.
Note:
The ULPI protocol allows automatic communication of system events, for example detection of Vbus presence. The OTG_HS controller has a bit to indicate a new session (SRQINT = 1).
Figure 13. USB HS via ULPI interface
External USB HS PHYs compatible via ULPI interface
The following table lists some external USB HS PHYs compatible through the ULPI interface.
Table 12. Compatible USB HS PHY
USB HS PHY
Tested on
Board
MCU
ISP1705AET
STM3240G-EVAL
STM32F407
STM3241G-Eval
STM32F417
STM3221G-Eval
STM32F207
STM3220G-EVAL
STM32F217
USB3300-EZK
STM32779I-Eval
STM32F777
STM32769I-Eval
STM32F769
STM32756G-EVAL
STM32F756
STM32746G-Eval
STM32F746
STM32479I-Eval
STM32F479
STM32F446E-Eval
STM32F446
STM32F439I-Eval
STM32F439
STM32F429I-Eval
STM32F429
USB3320C-EZK
STM32H753I-EVAL
STM32H753
STM32H743I-EVAL
STM32H743
STM32F769I-DISCO
STM32F769
STM32F746G-DISCO
STM32F746
USB applications through the embedded OTG_HS PHY
To operate USB HS on STM32F7x3 devices there is no need to connect an external HS PHY via ULPI, as they already include an internal HS USB PHY.
There are some other recommendations in addition to those detailed for the embedded USB FS PHY:
An external capacitor of 2.2 μF must be connected on the VDD12OTGHS pin.
The HS PHY has an OTG_HS_REXT pin needed for calibration. This pin must be connected to GND via an external precision resistor (3 KΩ ± 1%).
STM32 on USB-IF integrators list
The list of the STM32 devices with certified USB peripherals is available on www.usb.org. The table below summarizes the certified USB peripherals by STM32 device.
