UPD70F3451GC-UBT-A Datasheet, PDF (574/1191 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 10 MOTOR CONTROL FUNCTION
(4) Automatic dead-time width narrowing function (TABnOPT2.TABnDTM bit = 1)
The dead-time width can be automatically narrowed in the vicinity of 0% output or 100% output by setting the
TABnOPT2.TABnDTM bit to 1.
By setting the TABnDTM bit to 1, the dead-time counter is not cleared, but starts down counting if the TOBnm
(internal signal) output of timer AB changes during dead-time counting.
The following timing chart shows the operation of the dead-time counter when the TABnDTM bit is set to 1.
Figure 10-13. Operation of Dead-Time Counter m (1)
(a) In vicinity of 0% output (TABnCCRm register = i ≥ M + 1 − a/2, TABnCCR0 register = M, TABnDTC register = a)
16-bit
counter
0000H
TOBnm signal
(internal signal)
Dead-time
counter m _000H
TOBnTm
pin output
TOBnBm
pin output
Dead-time counter m starts counting down.
Negative-phase wave output width: (M + 1 − i) × 4
(e.g., output width is 4 where TABnCCRm = M).
(b) In vicinity of 100% output (TABnCCRm register = i ≤ a/2, TABnCCR0 register = M, TABnDTC register = a)
16-bit
counter
0000H
TOBnm signal
(internal signal)
Dead-time
counter m _000H
TOBnTm
pin output
TOBnBm
pin output
Note
Dead-time counter m starts counting down.
Positive-phase wave output width: (M + 1 − i) × 2 − (i × 2)
(e.g., output width is M × 2 − 2 where TABnCCRm = 0001H.)
Note The output width of the first wave differs from that of the second and subsequent waves immediately
after the TABnCTL0.TABnCE bit has been set. The first wave is shorter than the second wave because
the dead time is fully counted.
Remark n = 0, 1, m = 1 to 3
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User’s Manual U18279EJ3V0UD