18.3.3 Dead-Time Insertion Unit (TIMER0 only)
The Dead-Time Insertion Unit aims to make control of brushless DC (BLDC) motors safer and more efficient by introducing complemen-
tary PWM outputs with dead-time insertion and fault handling, see
Figure 18.39 TIMER Dead-Time Insertion Unit Overview on page
Dead time
insertion
Original PWM (TIM0_CCx_pre)
Fault
handling
Primary output (TIM0_CCx)
Complementary output (TIM0_CDTIx)
Fault sources
Figure 18.39. TIMER Dead-Time Insertion Unit Overview
When used for motor control, the PWM outputs TIM0_CC0, TIM0_CC1 and TIM0_CC2 are often connected to the high-side transistors
of a triple half-bridge setup (UH, VH and WH), and the complementary outputs connected to the respective low-side transistors (UL, VL,
WL shown in
Figure 18.40 TIMER Triple Half-Bridge on page 596
). Transistors used in such a bridge often do not open/close instan-
taneously, and using the exact complementary inputs for the high and low side of a half-bridge may result in situations where both gates
are open. This can give unnecessary current-draw and short circuit the power supply. The DTI unit provides dead-time insertion to deal
with this problem.
UH
VH
WH
WL
VL
UL
W
V
U
Figure 18.40. TIMER Triple Half-Bridge
For each of the 3 compare-match outputs of TIMER0, an additional complementary output is provided by the DTI unit. These outputs,
named TIM0_CDTI0, TIM0_CDTI1 and TIM0_CDTI2 are provided to make control of e.g. 3-channel BLDC or permanent magnet AC
(PMAC) motors possible using only a single timer, see
Figure 18.41 TIMER Overview of Dead-Time Insertion Block for a Single PWM
.
EFM32JG1 Reference Manual
TIMER - Timer/Counter
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