Understanding Basic Circuit Modules: Can You Comprehend Them?

DC voltage regulation power supply is the energy circuit for electronic devices, which relates to the stability and reliability of the entire circuit design, making it a critical aspect of circuit design. This section focuses on typical circuit designs composed of three-terminal fixed (positive and negative voltage) integrated voltage regulators, three-terminal adjustable (positive and negative voltage) integrated voltage regulators, and DC-DC circuits.

Power Supply Processing Block Diagram

The function of the rectifier circuit is to convert the AC voltage U1 into a pulsating DC U2. It mainly has half-wave rectification and full-wave rectification methods, which can be executed using rectifier diodes to form a rectifier bridge. Common rectifier diodes include IN4007, IN5148, etc., and bridge piles include RS210, etc. The filtering circuit’s function is to filter the ripple from the pulsating DC U2, turning it into a ripple-reduced U3. Common filtering circuits include RC filtering, KL filtering, and π-type filtering, with RC filtering being the most commonly used.

Centralized Rectification Form

In actual application circuits, in addition to connecting large-capacity filter capacitors between the chip’s input and output terminals and ground, small-capacity (0.1µF～10µF) capacitors Ci and Co are usually connected to ground at the base of the chip’s lead. Ci is used to suppress chip self-excitation oscillation, and Co is used to narrow the chip’s high-frequency bandwidth, reducing high-frequency noise. The specific values of Ci and Co should vary depending on the chip’s output voltage level and the application circuit’s method.

Basic Application Circuit of 78 Series Three-Terminal Voltage Regulator

Operational amplifiers can generally be divided into several types: general, precision, low noise, high speed, low voltage low power, and single supply.The parameters that represent the performance of operational amplifiers include: single/dual power supply operating voltage, supply current, input offset voltage, input offset current, input resistance, conversion rate, differential input resistance, offset current temperature drift, input bias current, bias current temperature drift, differential voltage gain, common mode voltage gain, unity gain bandwidth, power supply voltage rejection, differential input voltage range, common mode input voltage range, input noise voltage, input noise current, offset voltage temperature drift, settling time, long-term drift, etc.

In-phase Input Ratio Operational Circuit

Inverted Input Proportional Summation Circuit

Differential Amplifier Circuit

In various electronic design processes, it is necessary to generate various waveforms, such as square waves, sine waves, triangular waves, single pulse waves, etc. The generation methods mainly utilize operational amplifiers or dedicated analog integrated circuits, along with a few external components to form various types of signal generators.

Discrete Analog Circuit Constructing Square Wave Generation Circuit

Self-oscillating Equivalent Inductor Oscillator

Signal processing circuits mainly utilize integrated operational amplifiers or dedicated analog integrated circuits, along with a few external components to form various functional processing circuits. The main functions include signal amplification, signal filtering, impedance matching, level shifting, nonlinear compensation, current/voltage conversion, voltage/frequency conversion, etc.

Active Low-pass Filter Composed of Operational Amplifier

Sound Alarm Circuit

A sensor is a device or apparatus that can sense (or respond to) a specified physical quantity and convert it into a usable signal output according to a certain rule. Sensors typically consist of sensitive elements that directly respond to the measured quantity, conversion elements that produce usable signal outputs, and corresponding electronic circuits.

Basic Application of Hall Sensor

Photoelectric Detection Circuit

LED (Light Emitting Diode) displays are the most commonly used display devices made of light-emitting diodes. Digital LED displays use seven light-emitting diodes to display numbers, commonly referred to as seven-segment LED displays or digital tubes. Additionally, there is a round dot-type light-emitting diode in the digital tube used to display decimal points.

Internal Structure of LED Display

The principle of LCD display is that under the action of an external electric field, the liquid crystal molecules with dipole moments in the liquid crystal display device change their arrangement state, modulating the light passing through the liquid crystal display device, thus presenting the display effect of light and dark or transparent and opaque. Below we introduce the method and program for driving a dot matrix character LCD display module (MDLS) using FPGA.

LCD Display Module Circuit Block Diagram