Hello,
I am looking for a SATA Redriver 6GBps of speed -10 - 85C and which would support longer then 2m cable lenght say 4m. Do you offer one that would fall into this category?
Thanks,
Jacek
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Hello,
I am looking for a SATA Redriver 6GBps of speed -10 - 85C and which would support longer then 2m cable lenght say 4m. Do you offer one that would fall into this category?
Thanks,
Jacek
Hi Jacek,
We have these devices for SATA supporting up to 6Gbps:
SN75LVCP600: Temperature range 0 to 85
SN75LVCP600S: Temperature range -40 to 85
SN75LVCP601: Temperature range 0 to 85
The measurements we have for these devices are on FR4 no using cables.
Regards
Thanks Michael,
DS64BR111 looks promising for my application - Do you have apps note describing a typical application using resistors for 4 - 5m of SAS SATA cable? I am trying to get the loss number for cables of interest.
Thanks,
Jacek
Hi Michael,
you were asking for estimation of cable loss. The manufacturer lists:
Attenuation: 10 dB/9 m Maximum @ 1.25 GHz - so lets assume ~12dB for 4m and 3GHz.
What would be the recommendation?
Thanks,
Jacek
Hi Jacek,
Recovering 12 dB of loss should not be an issue for the DS64BR111. On the channel direction that is receiving the -12 dB of loss, EQ = 0x03 or 0x07 may work well (we have noticed that the eye quality typically looks better with slightly less EQ gain than the advertised dB boost at 3.2 GHz in the datasheet). On the channel direction that is transmitting across the cable, I think de-emphasis of -3.5 dB should be sufficient.
These are recommended starting points, and we recommend that you err on the side of less gain than more when inserting the redriver in the data path. We expect that the ASICs on either side of the redriver have additional signal conditioning mechanisms, and if the redriver over-equalizes the signal, it can sometimes present more harm than good for the endpoint.
As an additional resource, please check out Webench Interface Designer (also can be referenced on the DS64BR111 landing page), where you can simulate with a variable amount of loss in dB between our redriver and the endpoint device. The simulation model uses our IBIS-AMI model to provide an expectation of part performance before implementing the design physically on the bench.
Thanks,
Michael
Hi Michael,
following up on your response reg. the cable length:
I noticed within the device pin description VOD_SEL pin has a restrictive:
>>Note: DS64BR111 OUTA is limited to 700mV in pin mode, see Table 4 for additional information<<. Does it mean it is note suitable for the "long" cable application when I would prefer to use the ENSMB = 0 (PIN MODE) for simplicity of application?
Thanks,
Jacek
Hi Michael,
We will have a need to implement a solution for sending data over to 4 HD through the same cable. I see TI offers a chip ds64br401 which is similar to the one we discussed just before. I see the differences though power supply is 2.5V not 3.3V. - are there any other differences?
Fundamental question is if I need to used only one bidirectional channel or two is it the others not used would "harm" the functionality of those being used? Is there a way to disable those not being used?
Thanks,
Jacek
Hi Jacek,
As previously mentioned, the DS64BR401 is a previous generation, so there was only one supply (2.5 V). In later designs like the DS80PCI402/800 and DS125BR401A, we integrated an internal LDO and created a 3.3 V mode and 2.5 V mode so that users have the flexibility of providing either 3.3 V to the device or 2.5 V. If 3.3 V is supplied to these newer devices, the redriver will use the LDO to regulate the 3.3 V input down to an internal 2.5 V. Alternatively, you can supply 2.5 V to VDD directly and bypass the LDO. In the DS64BR401, the only option is to supply 2.5 V to the device. There is no internal LDO.
This difference in voltage supplies does not affect the ability to perform signal conditioning or be compatible with SATA/SAS/PCIe signals.
Any literature for these three chips that we have available are provided in the "Technical Documents" tab for their respective landing pages.
Thanks,
Michael
Thanks Michael,
sounds like your recommendation is DS125BR401A rather than the one I originally started with. It has the same 3.3V supply voltage option -40 - +85degC operating temp range [unlike DS64BR401 from -10degC]. So the last question is does it represent the same driving strength capabilities as DS64BR111 in terms of cable length? Does it have the same settings required as we discussed before?
Thanks,
Jacek