UPD70F3451GC-UBT-A Datasheet, PDF (569/1191 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 10 MOTOR CONTROL FUNCTION
10.4.2 Dead-time control (generation of negative-phase wave signal)
(1) Dead-time control mechanism
In the 6-phase PWM output mode, compare registers 1 to 3 (TABnCCR1, TABnCCR2, and TABnCCR3) are
used to set the duty factor, and compare register 0 (TABnCCR0) is used to set the cycle. By setting these four
registers and by starting the operation of TAB, three types of PWM output waves (basic 3-phase waves) with a
variable duty factor are generated. These three PWM output waves are input to the timer Qn option unit
(TMQOPn) and their inverted signal with dead-time is created to generate three sets of (six) PWM waves.
The TMQOPn unit consists of three 10-bit counters (dead-time counters 1 to 3) that operate in synchronization
with the count clock of TABn, and a TABn dead-time compare register (TABnDTC) that specifies dead time. If
“a” is set to the TABnDTC register, the dead-time value is “a”, and interval “a” is created between a positive-
phase wave and a negative-phase wave.
Figure 10-8. PWM Output Waveform with Dead Time (1)
16-bit
counter
TOBnm signal
(internal signal)
Dead-time
counter m
TOBnTm
pin output
TOBnBm
pin output
(a) When dead time is inserted (TABnDTC register = a)
a
a
16-bit
counter
TOBnm signal
(internal signal)
Dead-time
counter m
TOBnTm
pin output
TOBnBm
pin output
(b) No dead time (TABnDTC register = 000H)
0000H
0
0
Remark n = 0, 1, m = 1 to 3
User’s Manual U18279EJ3V0UD
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