Operation
34
DK58113 Developer Kit User Manual
2
As shown in
the MC58113 provides a shunt PWM output, which in turn drives a MOSFET switch on the
DK58113 board.
The resistor connected at J14 should have a resistance such that the current flow through the Shunt MOSFET does
not exceed 10 amps. For example with an HV supply of 48 Volts, this means a resistance of no less than 4.8 ohms.
The diode, which is connected in parallel to the resistor, should have a voltage and current rating at least equal to those
of the MOSFET. For the DK58113 this means a voltage and current rating of 100 volts and 10 amps or higher.
Beyond this limit, the actual resistance used is application specific and depends on the nature of the anticipated over
voltage generating conditions, the power supply used, and the wattage rating of the resistor.
Example: a shunt resistor with a resistance of 10 ohms is connected through the J4 shunt connector and a comparison
value of 51 Volts and a PWM duty cycle of 75% are specified. When the +HV voltage exceeds 51.0 Volts, HV will be
connected to GND via the shunt resistor resulting in an effective average current flow of (51.0V * .75)/10 ohms =
3.825 amps.
The default value of the shunt comparison mechanism is disabled. To enable, both a voltage comparison value and a
PWM output duty cycle are specified.
2.6
Connecting to a Remote Amplifier
Figure 2-7:
DK58113 to
Remote
Amplifier Card
Connections
In addition to the DK58113’s on-card switching amplifier, J12 provides connections for an external remote switching
amplifier. This connector is typically used to interface with user-designed amplifiers that service higher power motors,
or motor or actuators that require a special bridge configuration. Such an external amplifier connection is shown in
It is the responsibility of the user to connect and to specify a shunt-related resistor and diode that are safe for the
application being controlled.
Remote
Amplifier
DK58113
J1
J2
J12
+5V
+HV
Optional HV
