ISOUSB211: parameter confirm

Hi,

Thank you for reaching out and for showing interest in ISOUSB211. Please find my inputs below,

1. Typically the ESD requirements on the bus pins are in reference to Protected Earth (PE), as also stated in the standard IEC 61000-4-2.
   1. If this is the case then yes, the ISOUSB211 isolation barrier supports your ESD requirements.
   2. If the ESD applied needs to be met with respect to local ground, i.e., UD pins to GND1 and/or DD pins to GND2, then you would need external TVS diodes to meet the ESD requirements.
2. Yes, ISOUSB211 meets all of the USB-IF requirements. I would also like to mention that the USB standard doesn't have specifications defined for isolated USB products. Due to this, there are some specifications that are unique to isolators and not expected to match a non-isolated USB product. I am listing below the most significant examples,
   1. Since ISOUSB211 has two USB ports two it, it takes the timing budget or two hubs.
   2. ISOUSB211 is USB data isolator only and doesn't include power isolation. Power needs to be isolated externally using devices like SN6505 and supplied to the isolated side of ISOUSB211. Isolated power supplies typically do not have low quiescent current due to which the overall isolated USB solution might not meet the suspend mode current requirements of <0.5mA (100mA configuration) and <2.5mA (500mA configuration).
3. ISOUSB211 supports many additional features over competition, please find some of them listed below.
   1. Supports High Speed test modes to be compliance to USB 2.0
   2. Supports L1 (Sleep) power management state
   3. Doesn't require external clock/crystal
   4. Supports Dual Role where each side can be used to connect to a host or a peripheral
   5. Supports Role-Reversal where each port can be dynamically switched to host or peripheral allowing support for OTG
   6. Supports CDP advertising
   7. Has configurable built-in equalization and pre-emphasis
   8. Offers one of the industries highest isolation working voltage for isolated USB
4. The Tape & Reel information from ISOUSB111 seems to have accidentally added to ISOUSB211. Sorry about this and thanks for reporting this to us. We will get this fixed.

Let me know if you have any further questions, thanks.

Regards,
Koteshwar Rao

Hi Rao, thanks for replying in details.  some further questions. 

OK. Seems we do need TVS diodes. 

Koteshwar Rao said:

If the ESD applied needs to be met with respect to local ground, i.e., UD pins to GND1 and/or DD pins to GND2, then you would need external TVS diodes to meet the ESD requirements.

 and can you confirm this? It can withstand >4kV between two sides of the device.? I think it is 5.7KV(rms).

BX27 said:

Also need >4kv dielectric withstand voltage according to IEC60601-1.

and could you please help explain this in further ? Did you mean there are more time delay than un-isolated usb? and why need two hubs?

Koteshwar Rao said:

Since ISOUSB211 has two USB ports two it, it takes the timing budget or two hubs.

Hi,

Thanks for seeking further clarifications for better understanding.

BX27 said:

can you confirm this? It can withstand >4kV between two sides of the device.? I think it is 5.7KV(rms).

Yes, ISOUSB211 supports 4kV withstand voltage across the isolation barrier as it is rated for 5.7kVrms.

BX27 said:

could you please help explain this in further ? Did you mean there are more time delay than un-isolated usb? and why need two hubs?

No, it doesn't require two hubs. USB permits a maximum number of 6 tiers, i.e., it allows upto 6 devices to be connected in series. Please refer to the below image for reference. Since ISOUSB211 has two ports, it will take up 2 tiers in the hierarchy instead of 1 tier. If you are only using ISOUSB211 to connect to one host and one peripheral, then the tiers shouldn't be a concern to you. Thanks.

Regards,
Koteshwar Rao