0–5 V Analog Input
It is the low-voltage analog reference interface; 0 V means stop and 5 V means full command. Because it is in the same band as the microcontroller supply voltage, it needs no additional scaling circuit and matches potentiometer and joystick outputs directly. On the KS250, IN5 and on the PT500, input E are defined as the analog reference input; verify the range they accept from the diagram.
The 0–5 V band is the simplest solution because the 5 V regulator on the board can be used directly as the potentiometer supply line: the ends of the pot go to 5 V and chassis, and its wiper to the analog input. Since no converter or divider is inserted in between, there are fewer sources of error.
- Resolution: with a 10-bit ADC the 5 V scale is divided into 1024 steps, one step being about 4.9 mV. That is more than enough for speed setting.
- Noise sensitivity: because the scale is narrow, the same interference creates twice the percentage error compared with a 0–10 V input; if the cable exceeds 2–3 metres, use shielding.
- Overvoltage: applying more than 5 V to the input stresses the protection diodes; always use a divider when connecting a 0–10 V source.
In practice, adding a simple low-pass filter made of a 10 kΩ series resistor and a 100 nF capacitor on the reference line largely stops PWM switching noise from making the speed reference jitter.
Context where this term is used: DC Motor Driver Selection Guide