Introduction to Digital Power Conversion
XMC4000/1000 Family
Sensing
Application Guide 47 V1.0, 2015-01
Figure 34 VADC Channel in Fast Compare Mode
Fast Compare Result
The outcome from a Fast Compare event is an affected Fast Compare Result flag (FCR) associated
to the VADC channel.
The FCR flag is sticky; i.e. it keeps its status until the result reference level has been crossed again,
and untill te Outside-Band has been detected on the opposite side of the hysteresis range.
Fast Compare Performance
When using a VADC channel in Fast Compare mode for analog threshold sensing, the input voltage
is directly compared with a digital value in the result register, resulting in a single bit (above/below
comparison level).
This method is not as fast as using an analog comparator (ACMP or CSG), but would be suitable for
Low-end solutions.
Fast ADC Compare Properties
Conversion rate is 150ns.
Resolution is 10-bit.
5.1.2 PWM with Fast Compare mode Hysteretic Switching
The on/off sequences in a switch-mode power converter can be influenced by sensing the inductor
currents that ramp-up or down, according to the commutation of the switches.
In this example, an FCR influences PWM by ‘set/clear’ on ‘Out-of-Band’ crossing events.
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