Motherboard Design Guide
Requirements for Components of Third-party Suppliers
ESCON Module 50/4 EC-S Hardware Reference
5-28
CCMC | 2021-08 | rel9026
TVS DIODE (D1)
To protect against overvoltage resulting from voltage transients or brake energy feedback, we recommend
connecting a TVS (transient voltage suppressor) diode (D1) to the voltage supply cable.
CAPACITOR (C1)
The function of the ESCON Module 50/4 EC-S does not necessarily require the use of an external capacitor
(C1). To further reduce voltage ripple and feedback currents, an electrolytic capacitor can be connected to
the voltage supply cable.
5.1.3
Motor Cables / Motor Chokes
The ESCON Module 50/4 EC-S is not equipped with internal motor chokes.
The majority of motors and applications do not require additional chokes. However, in the case of high
supply voltage with very low terminal inductance, the ripple of the motor current can reach an unacceptably
high value. This causes the motor to heat up unnecessarily and causes instable control behavior. The
minimum terminal inductance required per phase can be calculated using the following formula:
If the result of the calculation is negative, no additional chokes are necessary. Nevertheless, the use of
chokes in combination with additional filter components can be useful to reduce the emission of electromag-
netic interference.
An additional choke must feature electromagnetic shielding, a high saturation current, minimal losses, and a
nominal current greater than the continuous current of the motor. The below wiring example refers to an
additional inductance of 22
μ
H. If a different additional inductance is required, also the filter components
must be adapted accordingly. Should you need further help with the filter design, contact maxon Support at
http://support.maxongroup.com.
Figure 5-18
Wiring of Motor Winding 1 (analogously valid also for Motor Windings 2 & 3)
Additional external inductance per phase
Operating vV
CC
Switching frequency of the power stage = 53 600 Hz
Nominal current of the motor (
line 6 in the maxon catalog)
Terminal inductance of the motor (
line 11 in the maxon catalog)
L
phase
1
2
---
V
cc
3
f
PWM
I
N
⋅
⋅
-----------------------------
0.3
L
motor
⋅
(
)
–
⋅
≥
L
phase
H
[ ]
V
cc
V
[ ]
f
PWM
Hz
[
]
I
N
A
[ ]
L
motor
H
[ ]
