Drive & DC Bus Safety
84
Juno Step Motor Control IC User Guide
13
13.4.1 Typical Overtemperature Processing
Circuitry
Figure 13-5:
Over-
temperature
Processing
Circuitry
shows a typical signal processing circuit for use with the
Temperature
input. The thermistor is a 10k NTC
temperature-voltage-decreasing type. C1 is referenced to analog ground and should be placed close to the
Temperature
pin of the MC58113. R3 is optional. It can provide additional filtering to improve noise immunity if needed.
Section 15.6, “Drive-Related Safety and Monitoring Features”
for a complete example schematic of temperature
input using Juno ICs.
13.4.2 Typical Overcurrent Processing Circuitry
The DC bus current supply sensor typically consists of a sense resistor, as shown in
, or a linear Hall sensor.
The analog processing circuitry required for each is somewhat different. If a dropping resistor is used an isolating
operational amplifier, current mirror, or similar circuit should be used. Linear Hall sensors typically use just a ground-
referenced operational amplifier.
The
BusCurrentSupply
input range is 0.0V to 3.3V with 0.0V representing no (zero) current flowing and 3.3 volts
representing the maximum measurable amount of current flowing. The signal should be filtered to minimize noise,
and the source impedance of the signal conditioning circuit should be less that 100 ohms. Current inputs are sampled
by a dedicated high speed circuit internal to the Juno IC. To minimize false positives a low pass filter with a roll off
value of 350 kHz is recommended.
13.4.2.1 Typical Overcurrent-Processing Circuitry
Figure 13-6:
DC Bus
Monitoring
Circuitry
