FREQDET28HPC is an IP for detection of input frequency and provides digital output as well as analog output to be used as indicator of the input frequency.
Basic principal of operation is frequency to voltage converter and converted analog output voltage is dependent on the process corner of the poly resistance and mom capacitor. IP can self-calibrate when predefined input frequency is applied at the calibration input. When a predefined calibration input is applied at the FCAL input pin and CAL=1, IP enters into self-calibration mode to trim the internal RINT, CREF and resulting calibration codes are provided to be stored in static memory of e-fuse. Post calibration it produces the output voltage and digitally converted 4b output to indicate the output frequency of the applied input which is proportional to the applied input frequency. IP includes complete reference generation, trimming circuits, digitizer and calibration engine. During normal operation mode when CAL=0, to trim the internal RC, Digital data DTRIM has to be applied from stored memory during calibration phase.