Datasheet

TMC8460-BI Datasheet (V1.00 / 2016-Sep-01)
Copyright © 2016 TRINAMIC Motion Control GmbH & Co. KG 138
Table 148 : MFCIO PWM block real world unit relations
Parameter Value Description / Function Comment
f
CLK
[Hz] 100 MHz clock frequency of PWM unit f
CLK
[Hz] = 1 / t
CLK
[s]
t
CLK
[s] 10 ns clock period length t
CLK
[s] = 1 / f
CLK
[Hz]
max. t
PWM
[s] 40,96us Length of PWM period
t
PWM
= t
CLK
* (1 + PWM_MAXCNT)
Maximum t
PWM
with maximum
PWM resolution of 12 bit.
min. f
PWM
[Hz] 24.414 kHz PWM frequency = 1 / t
PWM
Minimal PWM frequency with
maximum PWM resolution of 12
bit.
t
PULSE_LENGTH
Length of the ADC trigger pulses
with t
PULSE_LENGTH
= PULSE_LENGTH *
t
CLK
pulse length is adjustable to
trigger external ADCs
t
CLK
= 10ns
t
BBM
Brake Before Make time tBBM with
t
BBM_H
= BBM_H * t
CLK
t
BBM_L
= BBM_L * t
CLK
Individually programmable for
high side and low side due to
different timing requirements,
especially when using PMOS @
High Side and NMOS @ Low Side
6.9.1 PWM_MAXCNT Configuration Register
This register commonly defines the number of counts per PWM cycle for three PWM units. This
determines the length tPWM of each PWM cycle resp. the PWM frequency fPWM. It is programmable for
adjustment of the PWM frequency fPWM.
6.9.2 PWM_CHOPMODE Configuration Register
This Register commonly selects the chopper mode of the three PWM units. The following table gives
the available chopper modes.
PWM channel 0 chopper mode = PWM_CHOPMODE(2:0)
PWM channel 1 chopper mode = PWM_CHOPMODE(6:4)
PWM channel 2 chopper mode = PWM_CHOPMODE(10:8)
Table 149 : PWM chopper mode selection
Selection Chopper High Side (HS) Low Side (LS) Function
%000 no off off no chopper, all off
%001 no off on no chopper, LS permanent on
%010 no no off no chopper, HS permanent on
%011 no off off no chopper, all off, not used
%100 no off off no chopper, all off, not used
%101 yes off PWM chopper LS, HS off
%110 yes PWM Off chopper HS, LS off
%111 Yes PWM not PWM chopper HS and LS complementary,
brake-before-make is handled by
programmable BBB unit