Optional Circuitry - Texas Instruments TUSB8040AEVM User Manual

Optional Circuitry

6 Optional Circuitry
The TUSB8040AEVM design implements a variety of LEDs, none of which are required by the USB
specification. They are provided to make testing and debug easier.
• D1 – Indicates that the upstream USB port is connected at High-Speed.
• D2 – Indicates that the upstream USB port is connected at SuperSpeed.
• D3 – Indicates that the upstream USB port has entered a High-Speed suspend state.
• D4 - Indicates that the upstream USB port has entered a SuperSpeed suspend state.
• D5 – Indicates when VBUS is provided to the upstream USB port.
• D6 – Indicates that 5 V is being applied to the TUSB8040AEVM.
• D7, D8, D10, D11 – Indicate when VBUS is applied to the downstream USB ports. The
TUSB8040AEVM enables or disables power to all downstream USB ports simultaneously.
• D9 – Indicates BOARD_3P3V is active
• D12 – D15 (dual LEDs) – Implement the USB 2.0 specification for port indicator LEDs. These LEDs
indicate if the downstream ports are connected at USB 2.0 speeds (green) or if there is an over current
event on a downstream port (amber).
The TUSB8040AEVM incorporates ESD protection circuitry for the differential pairs of all five ports. The
TPD2EUSB30 devices are not required or populated on the EVMs, but are recommended for any system
where ESD events are a concern, especially if the end equipment requirements exceed the device
specifications (i.e. HBM 2000 kV, CDM 500 V) (SLVSAC2).
The switches present on the TUSB8040AEVM are intended for TI lab evaluation only and are not required
for production designs.
6
Hardware Overview
Copyright © 2012, Texas Instruments Incorporated
www.ti.com
SLLU163 – May 2012
Submit Documentation Feedback