Instantaneous pulse effect analysis of unidirectional TVS diode SMBJ16A

Now that technology is developing rapidly, this article will give you an in-depth explanation of the transient pulse effect analysis of the one-way TVS diode SMBJ16A . I hope it will help you.

The best way to handle transient damage to the device is to direct the instantaneous current away from the sensitive device. The TVS diode is connected in parallel with the protected line on the circuit board. When the instantaneous voltage exceeds the normal operating voltage of the circuit, the TVS diode avalanches, providing an ultra-low resistance path to the instantaneous current. As a result, the instantaneous current is diverted through the diode. Avoid the protected device and keep the protected loop at the off voltage until the voltage returns to normal. When the instantaneous pulse is over, the TVS diode automatically returns to the high-impedance state, and the entire loop enters the normal voltage. Many devices experience degradation and degradation of their parameters and performance after multiple shocks. As long as the operation is within a limited range, the diode will not be damaged or degraded. TVS devices are therefore ideal for protecting I/O interfaces, Vcc buses and other vulnerable circuits used in telecom, computer, industrial and consumer electronics applications. This article will introduce to you the basic parametric characteristics of the unidirectional TVS diode SMBJ16A for dealing with the damage of the transient pulse voltage to the device.

SMBJ16A parameters:

Package: DO-214AA
Voltage: 16.0V
Current: 23.08A
Clamping voltage: 26.0V
Power: 600W, more TVS transient suppression diode model parameters can directly access Shuokai electronic official website.

Features of SMBJ16A:

1. Optimize board space for surface mount applications 2. Low leakage 3, unidirectional and bidirectional unit 4, glass passivation junction 5, low inductance 6, excellent clamping capability 7, 600W peak power capability in 10×1000μ waveform Repeat rate (duty cycle): 0.01%
8, fast response time: from 0 volts to a minimum breakdown voltage is usually less than 1.0ps
9. Typically, when the voltage is higher than 12V, the reverse leakage current is less than 5μA.
10, high temperature welding: terminal 260 ° C / 40 seconds 11, the typical maximum temperature coefficient △ Vbr = 0.1% x Vbr @ 25 ° C x △ T
12, plastic packaging has insurance company laboratory flammability 94V-0
13. Lead-free tin-plated tin 14. Halogen-free, RoHS compliant
15. The typical failure mode occurs under the specified voltage or current. 16. The whisker test is based on JEDEC JESD201A in Tables 4a and 4c. 17. IEC-61000-4-2 ESD 15kV (air), 8kV (contact)
18. The ESD protection of the data line complies with IEC 61000-4-2 (IEC801-2)
19. The EFT protection of the data line complies with IEC 61000-4-4 (IEC801-4)

When choosing a TVS diode, you must pay attention to the following parameters:

1. In order to meet the IEC61000-4-2 international standard, TVS diodes must meet ESD strikes capable of handling minimum 8kV (contact) and 15kV (air), and some semiconductor manufacturers use higher impact standards on their products. . For some portable device applications with special requirements, designers can pick the device as needed.

2.Vwm This is the voltage that the diode can withstand in the normal state. This voltage should be greater than or equal to the normal working voltage of the protected circuit. Otherwise, the diode will continuously cut off the loop voltage; but it needs to be as close as possible to the normal working voltage of the protected circuit. So that the entire loop will not face the threat of overvoltage before the TVS works.

3. Vc This is the voltage that the diode provides in the off state, that is, the voltage through the TVS in the ESD strike state. It cannot be greater than the tolerable limit voltage of the protected loop, otherwise the device is in danger of being damaged.

4. Pppm rated pulse power This is based on the maximum cutoff voltage and the peak pulse current at this time. For handheld devices, a 500W TVS is generally sufficient.

5. Capacitance For loops with higher data/signal frequencies, the greater the interference of the capacitance of the TVS tube on the circuit, the noise is formed or the signal strength is attenuated. Therefore, the capacitance range of the selected device needs to be determined according to the characteristics of the loop. Generally, the high-frequency circuit should be chosen to have a small capacitance (such as LCTVS, low-capacitance TVS, and a capacitance of no more than 3pF), while the circuit capacitance that requires less capacitance can be higher than 40pF.