SPRUJ17H March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
The configuration options for the dead-band submodule are shown in Figure 7-182.
Although all combinations are supported, not all are typical usage modes. Table 7-160 documents some classical dead-band configurations. These modes assume that the DBCTL[IN_MODE] is configured such that EPWMxA In is the source for both falling-edge and rising-edge delay. Enhanced, or non-traditional modes can be achieved by changing the input signal source. The modes shown in Table 7-160 fall into the following categories:
Figure 7-183 shows waveforms for typical cases where 0% < duty < 100%.
Mode | Mode Description | DBCTL[POLSEL] | DBCTL[OUT_MODE] | ||
---|---|---|---|---|---|
S3 | S2 | S1 | S0 | ||
1 | EPWMxA and EPWMxB Passed Through (No Delay) | X | X | 0 | 0 |
2 | Active High Complementary (AHC) | 1 | 0 | 1 | 1 |
3 | Active Low Complementary (ALC) | 0 | 1 | 1 | 1 |
4 | Active High (AH) | 0 | 0 | 1 | 1 |
5 | Active Low (AL) | 1 | 1 | 1 | 1 |
6 | EPWMxA Out = EPWMxA In (No Delay) | 0 or 1 | 0 or 1 | 0 | 1 |
EPWMxB Out = EPWMxA In with Falling Edge Delay | |||||
7 | EPWMxA Out = EPWMxA In with Rising Edge Delay | 0 or 1 | 0 or 1 | 1 | 0 |
EPWMxB Out = EPWMxB In with No Delay |
Mode Description | DBCTL[DEDB-MODE] | DBCTL[OUTSWAP] | |
---|---|---|---|
S8 | S6 | S7 | |
EPWMxA and EPWMxB signals are as defined by OUT-MODE bits. | 0 | 0 | 0 |
EPWMxA = A-path as defined by OUT-MODE bits. | 0 | 0 | 1 |
EPWMxB = A-path as defined by OUT-MODE bits (rising edge delay or delay-bypassed A-signal path) | |||
EPWMxA = B-path as defined by OUT-MODE bits (falling edge delay or delay-bypassed B-signal path) | 0 | 1 | 0 |
EPWMxB = B-path as defined by OUT-MODE bits | |||
EPWMxA = B-path as defined by OUT-MODE bits (falling edge delay or delay-bypassed B-signal path) | 0 | 1 | 1 |
EPWMxB = A-path as defined by OUT-MODE bits (rising edge delay or delay-bypassed A-signal path) | |||
Rising edge delay applied to EPWMxA / EPWMxB as selected by S4 switch (IN-MODE bits) on A signal path only. | 0 | X | X |
Falling edge delay applied to EPWMxA / EPWMxB as selected by S5 switch (IN-MODE bits) on B signal path only. | |||
Rising edge delay and falling edge delay applied to source selected by S4 switch (IN-MODE bits) and output to B signal path only.(1) | 1 | X | X |
The dead-band submodule supports independent values for rising-edge (RED) and falling-edge (FED) delays. The amount of delay is programmed using the DBRED and DBFED registers. These are 10-bit registers and their value represents the number of time-base clock, TBCLK, periods by which a signal edge is delayed. For example, the formula to calculate falling-edge-delay and rising-edge-delay is:
FED = DBFED × TTBCLK
RED = DBRED × TTBCLK
Where TTBCLK is the period of TBCLK, the prescaled version of EPWMCLK.
For convenience, delay values for various TBCLK options are shown in Table 7-162. The ePWM input clock frequency that these delay values been computed by is 100 MHz.
Dead-Band Value | Dead-Band Delay in μS | ||
---|---|---|---|
DBFED, DBRED | TBCLK = EPWMCLK/1 | TBCLK = EPWMCLK /2 | TBCLK = EPWMCLK/4 |
1 | 0.01 μS | 0.02 μS | 0.04 μS |
5 | 0.05 μS | 0.10 μS | 0.20 μS |
10 | 0.10 μS | 0.20 μS | 0.40 μS |
100 | 1.00 μS | 2.00 μS | 4.00 μS |
200 | 2.00 μS | 4.00 μS | 8.00 μS |
400 | 4.00 μS | 8.00 μS | 16.00 μS |
500 | 5.00 μS | 10.00 μS | 20.00 μS |
600 | 6.00 μS | 12.00 μS | 24.00 μS |
700 | 7.00 μS | 14.00 μS | 28.00 μS |
800 | 8.00 μS | 16.00 μS | 32.00 μS |
900 | 9.00 μS | 18.00 μS | 36.00 μS |
1000 | 10.00 μS | 20.00 μS | 40.00 μS |
When half-cycle clocking is enabled, the formula to calculate the falling-edge-delay and rising-edge-delay becomes:
FED = DBFED × TTBCLK/2
RED = DBRED × TTBCLK/2