Datasheet

TMCC160 motionCookie™ (Rev. 1.00 / 2015-Nov-16)
© 2015 TRINAMIC Motion Control GmbH & Co. KG, Hamburg, Germany
Read entire DATASHEET USER MANUAL before use of product. Terms of delivery and right
s to technical change
reserved. Download newest version at: www.trinamic.com
28/39
4.8 Brake Chopper
A servo system feeds back energy to the power supply line during deceleration and load control.
The energy can lead to a voltage rise on the power supply system if it is not dissipated. The
voltage overshoot of a system without brake chopper depends on the motor deceleration time,
kinetic energy and the servo module buffer capacity. The brake chopper dissipates this energy
from the system, and thus avoids system damage.
TMCC160 provides a continuous motor voltage monitoring (20kHz) as well as a
brake chopper output. The brake chopper output pin is controlled from a
comparator implemented in TMCC160 software. Voltage threshold, hysteresis,
enable/ disable is configurable via software.
Motor voltage should be limited to 90% - 95% of the maximum possible
operation voltage.
For a full speed ramp stop, the brake resistor should be able to dissipate the
complete kinetic energy which is fed back during deceleration ramp (
.
).
Kinetic energy:


=


   
.

[
 =   ,  =  
]
Deceleration time:

.
Electrical energy:

.
=   
.
=





 
.
Brake resistor:


=





.


Formulae 6: Brake Chopper Resistor Calculation
Brake Chopper
Output
Brake Chopper
Example
Schematic
R
VM
Gate Driver
Brake (10)
VM
Software voltage threshold
TMCC160
Software hysteresis
Figure 21: Brake Chopper Example Schematic
4.8.1
Brake resistor
selection