THS6212: Functional mode recommend

Hello Emma,

If you have no strict power requirements (i.e. battery powered, etc), the best distortion and overall performance will occur with Full Bias mode.  When your system is not signaling, you may operate the amplifier in shutdown mode, reducing consumed power via quiescent current of the THS6212 and setting output to a high impedance node.

Best,

Alec

Hello Emma,

I would recommend using the Full Bias & Shutdown modes.  The THS6212 does not require 'stepping down' or single-bit changes of the control pins for bias mode.  If you do not need to use the mid-bias or low-bias modes, I would recommend using only two states for your design:

Sending: BIAS-1 = 0; BIAS-2 = 0

Receiving (THS6212 not in signal path): BIAS-1 = 1; BIAS-2 = 1

Best,

Alec

Hello Emma,

Your customer may be observing acceptable performance with either of the two methods you described above.  My response was based on the understanding of the theory behind the operation of the THS6212 device in a generic customer scenario.  Within the description section of the first page of the datasheet, the bias modes are described as selectable depending on line length.

For your customer's use case, their line length and data transmission parameters may perform as well as needed with Mid-Bias mode.  This is dependent on the details of your customer's system setup.  When recommending operating modes to customers, I recommend Full-Bias mode when power savings are not important, as I do not know the details of the customer system and want the performance to be as good as possible.  Mid-Bias mode has no performance benefit over Full-Bias mode, but the reduction in performance (for power savings) may be acceptable depending on your customer's system. 

Since your customer has done their diligence and observed the performance at different bias modes, they are welcome to use Mid-Bias mode if it performs to their required level.  As I have no information regarding the customer system, I cannot state whether a particular bias mode is better than another for that customer system.  

In general, it is fair to recommend the most performant mode as a starting point for the customer system.  If they value a low-power system, Low-Bias mode is the lowest-power transmission mode.  If a customer values performance over a long line distance, Full-Bias mode is recommended.  

For your customer (and customers without a low-power requirement), you can recommend Full-Bias first.  If their system is a shorter line length (requires less line power), you may step down into Mid-Bias and Low-Bias modes to see if performance targets are still met.  

To summarize, Mid-Bias mode works because your customer's system may not require the maximum performance of the THS6212.  Full-Bias mode will work in the system, but there are power savings from using Mid-Bias mode.  Your customer needs to evaluate if Mid-Bias mode has low enough distortion and can meet their performance targets.

Best,

Alec