Logical levels, i.e. one and one are not equal
The theory of digital circuits in terms of methods for representing logical states is very simple. In the most commonly used so-called positive logic - zero means the low state (L), and the voltage equal to the supply voltage (e.g. 3.3 V or 5 V) corresponds to logical one, i.e. the high state (H). So much theory; the practice, as usual, is much more complex. Each digital circuit correctly interprets input voltages within the range specified by the manufacturer, and the same applies to output signals, which cannot exceed a certain narrow range during normal operation. However, if one system (e.g. a microcontroller) is powered by 5 V and the other by 3.3 V, it is necessary to use a voltage converter (also called a logic level converter), which will not only ensure correct communication between individual systems, but also protect the systems. with a lower supply voltage from potential damage from too high input voltages.
Types and parameters of logical level converters
The basic division of voltage converters is based on in which (how many) directions these elements can transmit digital signals. Many converters transmit digital signals only in a specific direction, although some designs are able to work properly regardless of which direction the information is transmitted (i.e. which of the systems is the transmitter and which is the receiver). This is how very simple but highly effective voltage converters based on low-power MOSFET transistors work. In addition to the direction of operation, the key parameters of each converter are: the number of channels, acceptable voltage levels on both sides, as well as the maximum frequency of transmitted signals and - in some cases - propagation times (i.e. the delay between the change of the signal at the output in relation to the corresponding change at the input of a given channel). ).
Voltage converters available at the Botland store
In this category you will find a number of very useful modules, perfect for both prototype systems and target solutions. All voltage converters are offered in the form of universal modules with convenient goldpin connectors (soldered or intended for self-assembly) - and ready for use with connection cables, available in our store in practical sets. In addition to converters designed to work with digital outputs and inputs, we also have specialized modules enabling I2C communication. These modules (e.g. PCA9306) take into account the specificity of the physical layer of the I2C interface and enable trouble-free, stable cooperation of systems with different supply voltages.