ePWM Submodules
2032
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Enhanced Pulse Width Modulator (ePWM) Module
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 a signal edge is
delayed by. For example, the formula to calculate falling-edge-delay and rising-edge-delay are:
FED = DBFED × T
TBCLK
RED = DBRED × T
TBCLK
Where T
TBCLK
is the period of TBCLK, the prescaled version of VCLK3.
For convenience, delay values for various TBCLK options are shown in
.
Table 35-15. Dead-Band Delay Values in
μ
S as a Function of DBFED and DBRED
Dead-Band Value
Dead-Band Delay in
μ
S
DBFED, DBRED
TBCLK = VCLK3/1
TBCLK = VCLK3 /2
TBCLK = VCLK3/4
1
0.02
μ
S
0.03
μ
S
0.07
μ
S
5
0.08
μ
S
0.17
μ
S
0.33
μ
S
10
0.17
μ
S
0.33
μ
S
0.67
μ
S
100
1.67
μ
S
3.33
μ
S
6.67
μ
S
200
3.33
μ
S
6.67
μ
S
13.33
μ
S
400
6.67
μ
S
13.33
μ
S
26.67
μ
S
500
8.33
μ
S
16.67
μ
S
33.33
μ
S
600
10.00
μ
S
20.00
μ
S
40.00
μ
S
700
11.67
μ
S
23.33
μ
S
46.67
μ
S
800
13.33
μ
S
26.67
μ
S
53.33
μ
S
900
15.00
μ
S
30.00
μ
S
60.00
μ
S
1000
16.67
μ
S
33.33
μ
S
66.67
μ
S
When half-cycle clocking is enabled, the formula to calculate the falling-edge-delay and rising-edge-delay
becomes:
FED = DBFED × T
TBCLK
/2
RED = DBRED × T
TBCLK
/2