DG-IRMCK203 Datasheet, PDF (65/67 Pages) International Rectifier – Application Developer’s Guide

IRMCK203 Application Developer’s Guide
The duty counter, shown as “TA” in Figure 31, captures/latches the value at the falling edge of IR2175 and reset. Then
the counter waits for the next rising edge to start counting up. The carrier frequency counter (“TB”) captures/latches
the value at the rising edge of IR2175 and is immediately followed by re-counting at each IFB event.
At each IFB event, a multiply/divide operation is performed to cancel the temperature drift error of measurement. The
following is the basic multiply/divide operation:
TA(n) × 4096
Filtered _ TB(n)
Calculation starts immediately after the rising edge of the IR2175 signal as shown in Figure 31. This look-ahead
calculation is required to minimize the latency of data availability of the calculation result.
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