The voltage stabilization performance of the Zener diode can be expressed by its dynamic resistance r: r=(voltage change△U)/(current change△I). Obviously, for the same current change ΔI, the smaller the voltage change ΔU at both ends of the voltage regulating tube, the smaller the dynamic resistance, and the better the performance of the voltage regulating tube. The dynamic resistance of the Zener diode changes with the operating current, the greater the operating current. The smaller the dynamic resistance. Therefore, in order to achieve a good voltage stabilization effect, the operating current should be appropriately selected. If you choose a larger operating current, you can reduce the dynamic resistance, but it cannot exceed the maximum allowable current (or maximum power dissipation) of the tube. The working current and maximum allowable current of various types of pipelines can be found in the manual. The stability of the Zener diode is affected by temperature. When the temperature changes, its stable voltage also changes. The temperature coefficient of a stable voltage is usually used to express this performance. For example, the stable voltage UW of a 2CW19 Zener diode is 12 volts and the temperature coefficient is 0.095% ℃, indicating that for every 1 ℃ increase in temperature, the stable voltage increases by 11.4 millivolts. In order to improve the stability of the circuit, appropriate temperature compensation measures are usually adopted. When the requirement for stable performance is high, stable pressure with temperature compensation should be used, such as 2DW7A, 2DW7W, 2DW7C, etc.
1. VZ-stable voltage: refers to the stable voltage value generated at both ends of the voltage regulator when the rated current is passed. This value varies slightly with operating current and temperature. Due to different manufacturing processes, the voltage stabilization values of the same type of Zener diodes are not completely consistent. For example, the Vzmin of the 2CW51 type voltage regulator is 3.0V and the Vzmax is 3.6v.
2, IZ-stabilized current: refers to the current value through the Zener diode when the Zener diode generates a stable voltage. Below this value, although the regulator cannot stabilize the voltage, the stabilization effect will be worse. Above this value, as long as the rated power loss is not exceeded, it is also allowed. The voltage regulation performance will be better, but more power will be consumed.
3, RZ-dynamic resistance: refers to the ratio of voltage change and current change across the Zener diode. The ratio varies with the operating current. Generally, the greater the operating current of the Zener diode, the smaller the dynamic resistance. For example, when the operating current of the 2CW7C voltage regulator is 5mA, Rz is 18ω. When the operating current is 1mA, Rz is 8ω. When it is 20mA, Rz is 2ω; 20mA basically maintains this value.
4. PZ-rated power consumption: Determined by the allowable temperature rise of the chip, and its value is the product of the stable voltage Vz and the maximum allowable current Izm. For example, if the Vz of the 2CW51 Zener diode is 3V and Izm is 20mA, the Pz of the Zener diode is 60mW.
5. CTV-Voltage temperature coefficient: This is a parameter indicating that the stable voltage value is affected by temperature. For example, the Ctv of the 2CW58 regulating valve tube is 0.07%/c, that is, every time the temperature rises by 1°c, its regulating value will rise by 0.07%.
6. IR-Reverse Leakage Current: Refers to the leakage current generated by the Zener diode under the specified reverse voltage. For example, when the voltage of the 2CW58 regulator is 1 volt, infrared radiation = 0.1 A; when VR = 6V, IR = 10uA.
The above explained is the performance and parameters of Zener diodes. I hope that reading it will be helpful to you. If you want to know more about Zener diodes, please contact customer service online or call our company's service hotline. (Upper right corner of the website) For consultation, we will be happy to provide you with quality service!