USB-ISO – USB 2.0 compliant, 1000VDC
USB Full Speed isolator
User's manual
All boards produced by Olimex are ROHS compliant
Rev. E, January 2015
Copyright(c) 2015, OLIMEX Ltd, All rights reserved
Page 1
INTRODUCTION
USB-ISO is USB Full speed USB 2.0 compliant port isolator with 1000V isolation voltage.
USB-ISO is also often used by audiophiles to eliminate noise in audio systems or DACs.
This device is very useful as protects your PC computer USB host from over-voltages, ESD shock.
USB-ISO provides 1000VDC isolation and this way you can connect to your PC programmers and
debuggers which work directly with targets at high voltages like 220V mains power supply etc. Even
if your target is not connected to high voltage, USB-ISO is additional protection for your valuable
computer, laptop etc. USB-ISO may work with or without external power supply, if no external power
supply it generates with isolated DC-DC converter 5V isolated voltage for your USB device by taking
power from your USB host, if your USB device needs more power than your USB host can provide,
there is external power supply option you can connect any power supply adapter which provides
power supply from +8 to +15VDC and USB-ISO internal DC-DC will convert it to 5VDC for the USB
device. Note that in this case the external power supply should be ISOLATED as this DC-DC
converter is not isolated and the external power supply will be directly connected to your USB
programmer/debugger etc! Just your PC side will be isolated.
USB-ISO FEATURES
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USB isolation 1000VDC between USB host and USB device
Fully USB 2.0 Compliant
Full speed data rate 12 Mbps
Bidirectional communication
Short-circuit protection for xD+ and xD- lines
Class 3A contact ESD performance per ANSI/ESD STM5.1-2007
High common-mode transient immunity: >25 kV/µs
USB_DEVICE connector- which is USB-B type and have to be connected to the PC USB host.
USB_HOST connector which is USB-A type and have to be connected to the USB device like
USB JTAG, programmer, debugger etc
Power jack for external power supply with +8-15VDC, note this power jack is not isolated
from the USB_HOST connector (the personal computer is always protected; the power supply
and the device connected to the USB_HOST might influnce each other in case of fault)
DC-DC converter supply isolated voltage to the USB_HOST from the USB_DEVICE if no
external power supply is present
Dimensions 41.5×36.5mm (1.634×1.437")
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ELECTROSTATIC WARNING
The USB-ISO board is shipped in protective anti-static packaging. The board must not be subject to
high electrostatic potentials. General practice for working with static sensitive devices should be
applied when working with this board.
BOARD USE REQUIREMENTS
Cables:
You need two 1.8 meter USB A-B cable to connect to the PC and to your USB device. Note
these cables should be with LOW resistance (under 1 ohm) and good insulation, on the market there
are cheap cables with HIGH resistance (above 1 ohm) and poor insulation which are not good for USB
connection and cause signal fading and lost of communication packets.
USB target speed:
It is important to notice that the unit protects and shield USB full-speed devices or
devices that can enter USB full-speed mode. USB-ISO would not work with low-speed devices (like
keyboards or mice). It would neither work with high-speed-only devices. You can use a USB analyzer
program to determine the USB speed of your USB target.
USB target:
If you have to power your target device only from the personal computer make sure it
doesn't consume more than 350mA or you might need to provide external power supply either to the
target or to the USB-ISO's power jack.
SOFTWARE DRIVERS
USB-ISO does not need any software drivers.
SAFETY AND REGULATORY APPROVALS:
The USB isolator component used in USB-ISO have the following regulatory approvals:
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UL recognition: 5000 V rms for 1 minute per
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UL 1577 (pending)
CSA Component Acceptance Notice #5A
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IEC 60601-1: 125 V rms (reinforced)
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IEC 60950-1: 380 V rms (reinforced)
VDE certificate of conformity (pending)
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DIN V VDE V 0884-10 (VDE V 0884-10):2006-12
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VIORM = 846 V peak
POWER SUPPLY CIRCUIT
USB-ISO can take power from two sources:
- External power jack – 8V to 15 V DC, in this case maximum current available depend on the
maximum current which your external power supply can provide, up to 750 mA
- USB_DEVICE connector – 5V, in this case maximum current available depend on the maximum
current which PC USB host can provide, up to 350 mA
Page 3
CONNECTOR DESCRIPTIONS
USB_DEVICE
This is a USB type B connector. It is used to connect to the PC USB host. It is typically used to power
the USB-ISO and, sometimes, your target USB device (that is connected to the board's USB_HOST
conenctor).
USB_DEVICE and USB_HOST connectors are completely isolated from each other.
It is important to notice that personal computer USB ports usually provide up to 500mA. USB-ISO
consumes up to 150mA, which leaves up to 350mA for the device connected to USB-ISO. If your
device needs more current make sure to provide external supply to either the device or to the power
jack of USB-ISO.
Pin #
1
2
3
4
Signal Name
+5V_USB_DEV
DEV_D-
DEV_D+
GND_DEV
USB_HOST
This connector is used to connect to USB-ISO to your USB device that needs over-voltage protection –
programmer, debugger, etc which you want to isolate from your PC.
Pin #
1
2
3
4
Signal Name
HOST_PWR
HOST_D-
HOST_D+
GND_HOST
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PWR_JACK
This connector is used to provide additional power supply to your target device (the device that is
connected to USB_HOST). If your target draws more than 350mA of current you might consider using
the power jack. The maximum tested current that USB-ISO can provide with a capable external power
supply is 750A. If you have both external power supply provided and USB cable in USB_DEVICE
connector the maximum current available would raise to 1A.
This power jack is not isolated from the USB_HOST connector (the personal
computer is always protected, however, the power supply and the device
connected to the USB_HOST might influence each other in case of fault).
The voltage you need to provide to the power jack is in the range of 8V to 15V DC. The power jack
can't work with AC voltage. Make sure the voltage you provide is not more than 15V DC.
The power jack used is the typical DC barrel jack one used by Olimex in most of our products. More
information
about
the
exact
component
might
be
found
here:
https://www.olimex.com/wiki/PWRJACK
Pin #
1
2
Signal Name
Power Input
GND_HOST
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51单片机
