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Why is input clipping diode removed from positive bus?
The input clipping diode to ground is to protect from less than zero volt spikes. The input clipping diode to the positive bus is removed in favor of the zener diode after the current limiting resistor. This provides a known voltage for the input pin and reduces the amount of current shunted to the power bus.
How big is an input resistor in a microcontroller?
The input resistor is sized so that the voltage drop across it does not affect the voltage at the microcontroller input. As this is a simple voltage divider, and the input resistance in the controller is about 20 MΩ, this resistor can be fairly big. For most digital inputs, a good value is between 100 Ω and 10 kΩ.
How are inputs controlled in a generic electronic system?
In a generic electronic system there are some inputs that are controlled by the end user. These inputs are read by electronics and acted upon by using outputs. Protecting Inputs in Digital Electronics | DigiKey
Where do the inputs in an electronic system come from?
In a generic electronic system there are some inputs that are controlled by the end user. These inputs are read by electronics and acted upon by using outputs. The inputs can come from a myriad of sources: buttons, switches, sensors, relays, and communication devices, to name a few.
What’s the maximum input voltage for a PIC controller?
The datasheet may say maximum input is Vcc + 0.3 V, but it may also say maximum 20 mA for the clamping diodes (for instance this PIC controller. That may mean that the clamping diode voltage drop is less than 0.3 V, for instance if they’re Schottky’s.
When to add resistor to protection clipper circuit?
If your signal comes from a low impedance output you’ll want to add a series resistor to protect the clamping diode against a too high current. 50 mA is often specified as Absolute Maximum Rating. If you use a 15 kΩ resistor you’ll limit the current to 1 mA for a 20 V input.
How to produce negative output voltages from positive inputs?
can be easily confi gured to generate negative output voltages by confi guring it as an inverting buck-boost converter, as illustrated in Figure 1. The negative terminal of the input supply is connected to the VOUT pin of the μModule regulator and the GND pin is tied to the –V OUT rail. The actual input voltage (V IN’) seen by the μModule