The negative swings which occur after a button actuation can reduce sensitivity for multiple sequential button presses. While BTPAUSE is often a more effective algorithm for applications in which this is an issue, Fast Tracking Factor provides an increased Baseline Increment when OUTx is negative. Figure 5-6 compares the operation with and without Fast Tracking Enabled for an example stimuli. Each channel can be set with an independent setting for Fast Tracking – FTFx field can be set between 0 and 3.

Figure 5-6 Effect of Fast Tracing on Output Code

The following pseudo-code shows the effective change in Baseline Tracking when Fast Tracking Factor is enabled:

If raw_data[channel] > baseline[channel] then

baseline[channel] = baseline[channel] + base_increment

If raw_data[channel] < baseline[channel] = FTH) then

baseline[channel] = baseline[channel] - FTF * base_increment

Else If raw_data[channel] < baseline[channel] then

baseline[channel] = baseline[channel] - base_increment

The value of FTF is set by:

FTF = 2^{FTH×Field Value}

Where FTH is a correction to the FTF based on the device gain.

Fast Tracking is a multiplier onto the Baseline tracking setting. It is applied in both Normal Power mode and Low Power mode with the same scaling factor.