USB Accelerator datasheet

Features

  • Google Edge TPU ML accelerator coprocessor
  • USB 3.0 Type-C socket
  • Supports Debian Linux on host CPU

Overview

The Coral USB Accelerator is a USB device that adds an Edge TPU coprocessor to your system. It includes a USB socket so you can connect it to any Linux-based system to perform accelerated ML inferencing.

The onboard Edge TPU is a small ASIC designed by Google that provides high performance ML inferencing with a low power cost. For example, it can execute state-of-the-art mobile vision models such as MobileNet v2 at 100+ fps, in a power efficient manner.

Table of contents

System requirements

The Coral USB Accelerator must be connected to a host computer with the following specifications:

  • Any Linux computer with a USB port
    • Debian 6.0 or higher, or any derivative thereof (such as Ubuntu 10.0+)
    • System architecture of either x86-64 or ARM32/64 with ARMv8 instruction set

Components overview

The Coral USB Accelerator is a small PCB that provides an Edge TPU coprocessor for your host CPU system.

Feature Details
ML accelerator
Edge TPU
  • ASIC designed by Google that provides high performance ML inferencing for TensorFlow Lite models
Connections
USB
  • USB 3.1 (gen 1) port and cable (SuperSpeed, 5Gb/s transfer speed)
  • Included cable is USB Type-C to Type-A and 300 mm long (12 in)

Product dimensions

Figure 1. Device dimensions and mounting hole details

USB cable length: 300mm +/- 20 mm

Software and operation

The USB Accelerator doesn't require any software installed, but the host computer to which it's attached must install the Edge TPU runtime and API library. For instructions, see the Get Started guide.

For information about how to create models and run inferences the Edge TPU, read TensorFlow models on the Edge TPU.

Performance settings

When you first set up the USB Accelerator, you can select whether to use the default or maximum clock frequency. The maximum clock frequency runs at 2x the default setting, which increases the inferencing speed, but also increase power consumption.

Caution: If you enable the maximum operating frequency, the USB Accelerator becomes very hot to the touch during operation and might cause burn injuries. Either keep the device out of reach when using with the maximum frequency or instead use the default clock frequency to avoid injury.

To change this setting later, simply rerun the install script, in which you'll be prompted again to select the operating frequency. However, if you first installed the Edge TPU runtime library before April 2019, you should follow these upgrade steps.

LED behavior

The USB Accelerator includes an LED that lights up according to the current system state, as indicated in the following table.

System stateLED behavior
Edge TPU initializedOn (solid)
Edge TPU runningPulse (breathe)

Power specifications

The Coral USB Accelerator is powered by 5V from USB interface (USB_VBUS) through on board power management chip (PMIC).

The device should be connected to a host computer with a USB cable that provides at least 500mA at 5V.

During normal operation, the Coral USB Accelerator may heat up, depending on the computation workloads and operating frequency. Touching the metal part of the device after it has been operating for an extended period of time may lead to discomfort and/or skin burns. As such, we recommend the following operating temperature ranges, depending on the operating frequency you've selected.

Operating frequency Max ambient temperature
Default 35°C
Maximum 25°C

Google does not accept any responsibility for any loss or damage if the device is operated outside of the recommended ambient temperature range.

Environmental and electrical reliability tests

Test Conditions Verified
Heat soak Non-op: 60°C/90%RH 72hrs
Temp cycling Non-op: -20°C/60°C 300 cycles
Short term survivability Non-op: 85°C/20%RH, 18hrs 18 hours
Long-term operational stress (LTOS) Op: 40°C/90%RH 1000 hours
ESD - Air discharge 15~35°C, 30~60% RH 12 kV
ESD - Contact discharge 15~35°C, 30~60% RH 8 kV

Mechanical reliability tests

Test Conditions Verified
0.5m controlled drop on wood 6 faces, 12 edges, 3/4" wood 18 drops
0.5m tumble Impact surface: steel plate > 3 mm thick 50 drops
Repetitive drop 75 mm drop on plywood, six faces 50 drops
Vibration 3 axes (X, Y and Z), 15 minutes per axis, 10-500Hz. Amplitude: 2.16 Grms 45 minutes
USB-C connector cycling Manual plug/ unplug 1000 cycles
USB-C connector side load 2.5kg 2.5 kgf load, 15 mm from the plug, 2 orientations 50 cycles
Pressure & squeeze - 50kg 50 kgf, 100 mm rubber pad 10 cycles
Pressure & squeeze - 5kg 5 kgf, 10 mm rubber pad 10 cycles
USB cable 120° bend 60° CW + 60° CCW, 453 gf tension, 42 rpm 100 cycles

Certifications

Market Certifications
USA FCC
European Union CE
Japan VCCI
Korea KCC