Hardware

The previous article mentioned that in order to suppress the influence of high-frequency noise, the 4-20mA current sampling circuit needs to add an RC low-pass filter before ADC sampling. The RC low-pass filter circuit shown in Figure 1 is adopted, where R2 is 1.6K and C1 is 0.1uF. Then the cutoff f...

Figure 1. Non-synchronous BUCK converter topology Figure 1 shows the topology of an asynchronous BUCK converter. Asynchronous BUCK converter chips typically integrate only the high-side MOSFET internally. A freewheeling diode needs to be installed between the SW pin and GND as the freewheeling path...

In a step-down switching converter, the theoretical peak current that the power inductor can withstand is IL,PK=(1+r/2)×IOUT. This is the basis for the minimum value of the rated current or saturation current of the power inductor. The actual selection value needs to be greater than the theore...

When designing switching power supply circuits, we typically calculate the output ripple using the following formula: If the capacitor used is an MLCC (Multi-Layer Ceramic Capacitor), its ESR is negligible due to its very low value. Therefore, based on the input/output voltage, switching frequency,...

In the STM32 reset circuit shown in Figure 1, a switching diode is usually connected in parallel with the resistor terminal of the RC reset circuit. The main function of this diode is to accelerate the release of capacitor charge. Figure 1 STM32 reset circuit Figure 2 Discharge path of STM32 reset c...

In industrial applications, to accurately measure temperature values, we typically use a PT100 bridge circuit to sample and convert resistance changes into voltage changes. To obtain different measurement ranges, the sampling resistors are divided into 100 ohms and 50 ohms. Method 1 and Method 2 are...

RS232 (also known as EIA RS-232) is one of the commonly used serial communication interface standards. It uses full-duplex communication and requires three lines: ground, transmit, and receive. RS-232 is only suitable for point-to-point communication between devices. Due to its single-ended signal,...

RS485 is widely used in various fields such as industrial intelligent instruments and communication equipment due to its strong anti-interference ability and low cost. However, industrial environments are complex and subject to severe electromagnetic interference. Non-isolated RS485 systems have the...

The function of a TVS (Transient Voltage Suppressor) is to protect electronic circuits from damage caused by transient overvoltages (such as lightning strikes and electrostatic discharge).  It ensures circuit safety by rapidly clamping and diverting surge energy. In TVS protection circuit desig...