The post 展會圓滿收官】金譽半導體閃耀NEPCON Thailand 2025，收獲滿滿！ first appeared on HT Semi.
]]>展會亮點回顧：
? 接待專業(yè)訪客500+人次
? 達成初步合作意向客戶80+家
? 與3家泰國頭部電子制造商建立戰(zhàn)略合作
我們的創(chuàng)新產(chǎn)品獲得高度關(guān)注：
-
最新SiC功率器件解決方案
-
高可靠性存儲芯片封裝技術(shù)
-
智能MOSFET系列產(chǎn)品
衷心感謝：
所有蒞臨展位的客戶伙伴
展會主辦方的大力支持
金譽團隊的專業(yè)表現(xiàn)
雖然展會已結(jié)束，但我們的服務(wù)永不停歇！
The post 展會圓滿收官】金譽半導體閃耀NEPCON Thailand 2025，收獲滿滿！ first appeared on HT Semi.
]]>The post HTsemi at INATRONiCS 2025 – Pioneering Innovation in the Electronics Industry first appeared on HT Semi.
]]>Join HTsemi at INATRONICS 2025, the most influential electronics industry platform in Indonesia, taking place from April 23 to 25, 2025, at JIExpo Kemayoran, Jakarta. As part of this dynamic event, HTsemi is excited to showcase its cutting-edge power device solutions, including MOSFET semiconductors, tailored for a variety of applications in modern electronics manufacturing.
With the Indonesian government’s strong backing and the participation of major associations like GABEL, HTII, Aperlindo, Gamatrindo, and APKABEL, INATRONICS 2025 promises to be ASEAN’s premier trade event for consumer electronics and manufacturing industries. HTsemi’s presence at the exhibition will provide industry professionals with exclusive insights into our latest products, partnerships, and innovations.
Visit us at?stand B1D3-02?to experience firsthand our advanced power devices that meet the evolving needs of electronics manufacturers. Don’t miss this opportunity to connect with key players in the industry, explore sustainable solutions, and discover the future of electronics at HTsemi’s booth.
The post HTsemi at INATRONiCS 2025 – Pioneering Innovation in the Electronics Industry first appeared on HT Semi.
]]>The post How to investigate the specific causes of faults in DC-DC buck converters first appeared on HT Semi.
]]>In electronic systems, current is converted from DC or AC and regulated into a low-voltage power rail for use by electrical loads in the system. In this process, the presence of buck converters is indispensable. They have a wide input voltage range, high efficiency, and compact packaging, which is conducive to meeting the requirements of strict energy efficiency regulations and guarding the last link of low-voltage DC power rail conversion.
Therefore, problems with DC-DC buck converters will directly lead to situations where they cannot be used. But there are many reasons for the failure of DC-DC buck converters, such as switch mode, low voltage, DC-DC, single-phase, non isolated, basic buck converter circuits, etc. So how to troubleshoot? Let me explain in detail nine common problems that may be encountered when designing DC-DC buck converters and some possible reasons.
Problem # 1: Too much ripple
If you see too much ripple, the inductance value may be too low – higher values will produce lower ripple, but the transient response is slower.
In addition, please remember that a large inductor ripple current means higher peak current and greater likelihood of inductor saturation, especially at high temperatures – as well as greater pressure on the FET.
Other issues may be that the C out is too low and there is not enough storage space to support output; Or C out ESR (equivalent series resistance) is too high, resulting in IR voltage drop in C out.
Finally, a low switching frequency will result in more ripple.
Problem # 2: Unable to start
Firstly, ask yourself this question: Is the ‘enable’ pin correctly driven (or pulled up)? The same goes for good power output.
Startup failure may be due to seeing excessive load capacitance (such as FPGA) acting like a short circuit and triggering current limitation. Some chips have blanking and soft start functions to solve this problem.
Set the current limit point as high as possible to avoid false alarms, and consult with FPGA engineers to optimize the system level capacitance.
Finally, ensure that V in does not sag and that UV locking is not activated due to input pressure drop.
Problem # 3: Inefficient
The bootstrap capacitor needs to be large enough to provide charge to the gate of the high side FET – otherwise, the FET may not be fully conductive and may burn out the power supply. The resistor connected in series with the boost pin can be used to adjust the turn-on to control ringing.
Measuring power circuit efficiency (especially above 90%) is not an easy task as it requires current measurement and is the ratio of two power quantities. Hope you have described the contribution of each component to losses through a spreadsheet tool, which typically tells you that MOSFETs and inductor resistors (“DCR” or DC resistors) are the main sources of wasted heat.
undefined
Display the efficiency frequency relationship diagram of the buck switching regulator. The plot is taken from the LT8610 data sheet of Linear Tech/Analog Devices.
Problem # 4: There is voltage at the output terminal when it is turned off
If your circuit is indeed turned off but you see voltage at the output, it usually comes from another power circuit. Detected non obvious paths of other activity tracks.
Question # 5: Unstable
C out ESR may be the reason for instability, as it introduces zero in the loop response, which causes the gain curve to stop decreasing and begin to shift laterally, eroding or eliminating the gain margin. If the zero frequency is low enough, the gain will not exceed zero before the phase reaches 180 °.
Cheaper converter chips may have internal compensation to save external parts, but please ensure that your C output meets their stable minimum and maximum C output ESR ranges.
Other explanations for instability may include poor voltage detection or summation node layout or noise.
Please make sure to use design software to generate Bode plots and check phase and gain margins, including over temperature conditions.
Problem # 6: Improper regulation
For remote V out sensing, the Ohmic voltage drop in the power path may cause poor regulation, which may be due to the power rail (single power converter output line) being allocated too much load on the circuit board. That’s why sometimes multi rail converter ICs (PMICs) are avoided to support multiple converters next to the load.
If your voltage detection pin has noise, please keep the layout of the pin neat and ensure that any resistors related to the detection signal are placed near the controller.
Another explanation is that your reference voltage may be unstable when there is insufficient filtering.
Problem # 7: Slow transient response
The culprit here may be too many high-capacity output capacitors or too large inductors.
Another issue may be poor loop compensation. Without suitable equipment, it is difficult to fully characterize the loop characteristics. However, even if you don’t have a network analyzer, you can still use a step load and observe transient ringing – it will tell you a lot of cheap things.
In addition, during the development process, if the design load changes, compensation usually must also change. For example, do you use a factory evaluation module at half of its designed load? You see the problem.
Question # 8: Low temperature issue
Please remember that the ESR of electrolytic capacitors will increase and the capacitance will decrease at low temperatures.
Question # 9: PMBus issue
On the shared data communication bus, ensure that another node does not intermittently shake when you are not paying attention.
Additionally, please ensure that the pull-up resistor you are using is strong enough: a 47k Ω pull-up resistor (such as FPGA) is not as good as a 10k Ω one.
It is not difficult to see from the above that when troubleshooting, it is important to consider which variables are at work and reduce the number of possible causes of the fault. Considering these concepts before starting the investigation can provide a clearer understanding, reduce the possibility of trial and error, and save more time.
Here are some guidelines that can help you:
1. You need to reliably prevent the system from troubleshooting it. A problem that disappears on its own will come back on its own.
2. Change only one thing at a time and pay attention to the effect.
If the circuit stops working, ask ‘What changes have occurred?’ Is there an event that occurred simultaneously with the failure?
4. Check if the fault moves with the conversion board or load.
The post How to investigate the specific causes of faults in DC-DC buck converters first appeared on HT Semi.
]]>The post The working principle, characteristics, and function of field-effect transistors first appeared on HT Semi.
]]>Field Effect Transistor (FET) stands for Field Effect Transistor. A typical transistor is called a bipolar transistor due to the participation of two types of polar carriers, namely the majority carrier and the reverse polarity minority carrier, in conduction. FET, on the other hand, is only composed of the majority carrier, which is the opposite of bipolar transistors and is also known as a unipolar transistor.
1. MOS field-effect transistor
MOS field-effect transistors?are divided into N-channel transistors and P-channel transistors. Usually, the substrate is connected to the source electrode S. As mentioned before, MOSFETs are divided into enhanced and depleted types based on their different conductive methods. The so-called enhanced type refers to: when VGS=0, the tube is in a cut-off state, and after adding the correct VGS, most carriers are attracted to the gate, thereby “enhancing” the carriers in that region and forming conductive channels. The depletion type refers to the formation of a channel when VGS=0, and when the correct VGS is added, it can allow most carriers to flow out of the channel, thus “depleting” the carriers and causing the tube to turn towards cutoff.
2. The working principle of field-effect transistors
Field effect transistors are mainly composed of three regions: gate, drain, and source. Under normal operating conditions, the gate voltage controls the current between the source and drain, thereby achieving control over the field-effect transistor.
When the gate voltage is below the threshold voltage, there is no conductive channel between the gate and the channel, and electrons cannot flow from the drain to the source. The field-effect transistor is in a cut-off state, acting as an insulator.
When the gate voltage is higher than the threshold voltage, a conductive channel is formed between the gate and the channel, and electrons can flow from the drain to the source along the channel. At this point, the carrier concentration near the source increases, forming a conductive region called an inversion layer (N-type or P-type).
As the source voltage further increases, the width of the inversion layer will increase, and the electron concentration in the channel will also increase. In this way, more electrons can flow from the drain to the source, forming conductive channels. When the source voltage reaches a certain value, the electron concentration in the channel is large enough to make the entire channel conductive.
When the gate voltage is 0V, due to the disappearance of the insulation layer between the gate and the channel, electrons in the channel can freely flow between the drain and source. This means that the field-effect transistor is in a conductive state.
Taking the N-channel as an example, it creates two high doping concentration source diffusion regions N+and drain diffusion regions N+on a P-type silicon substrate, and then leads out the source electrode S and drain electrode D respectively. The source electrode and substrate are connected internally, and both maintain an equal potential. The leading direction in the symbol is from the outside, indicating an N-shaped channel from the P-type material (substrate). When the positive pole of the power supply is missed and the source pole is connected to the negative pole of the power supply and VGS=0, the channel current (i.e. drain current) ID=0. As VGS gradually increases and is attracted by the positive gate voltage, a few negatively charged carriers are induced between the two diffusion regions, forming an N-type channel from the drain to the source. When VGS is greater than the opening voltage VTN of the transistor (usually about+2V), the N-channel transistor begins to conduct, forming a drain current ID.
3. The role of field-effect transistors
1. Field effect transistors can be applied for amplification. Due to the high input impedance of field-effect transistor amplifiers, the coupling capacitor can have a smaller capacity and does not require the use of electrolytic capacitors.
2. The high input impedance of field-effect transistors is very suitable for impedance transformation. Commonly used for impedance transformation in the input stage of multi-stage amplifiers.
3. Field effect transistors can be used as variable resistors.
4. Field effect transistors can be conveniently used as constant current sources.
5. Field effect transistors can be used as electronic switches.
If you want to know more about semiconductor related knowledge, you can follow Jinyu Semiconductor.
The post The working principle, characteristics, and function of field-effect transistors first appeared on HT Semi.
]]>