I just purchased the FTDI 3.3 volt cable. Although It states that it will work fine with 5 volt logic I am concerned. The system I will be using it with (Sirius SC-H1 satellite tuner) states its interface to be 5 volt TTL.
Does anyone know if this cable will work or do I need the FTDI 5 volt cable?
FTDI Cable
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- Franklin97355
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Re: FTDI Cable
Most logic will switch around the half way point with hysteresis so the 3.3v would be OK for most logic and 0v is always OK.
- baldengineer
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Re: FTDI Cable
What is the difference between the product description saying it will work okay and people on a forum?BARRYGORDON wrote:I just purchased the FTDI 3.3 volt cable. Although It states that it will work fine with 5 volt logic I am concerned.
The chip inside actually runs on 5V. However, its output is only 3V. It can still accept input up to 5V. Since your device is 5V TLL, this works fine. A TTL input signal is defined as "low" when between 0 V and 0.8 V with respect to the ground terminal, and "high" when between 2.2 V and 5 V.
Table 4.3.2 of the datasheet linked to on the FTDI cable's product page, shows the Voh to be at least 2.2V.
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