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dangerous
[*] [-] [-] [x] [A+] [a-]  
[l] at 6/4/23 11:00am
App note from Holtek on their Real time clock IC HT1382. Link here (PDF) The HT1382 is a low power real time clock device which includes two serial interfaces: I2C or 3-wire. The interface mode is selected by the selected device type. The device provides both clock and calendar information in BCD format and also includes alarm functions that can be read or setup by an external device, which is usually an MCU and which will be the master device. The calendar is accurate until the year 2099 and includes automatic leap year correction.

[Category: app notes, app note, Holtek, real time clock]

[*] [-] [-] [x] [A+] [a-]  
[l] at 6/4/23 7:00am
App note from Holtek on their CAN Bus controller chip HT45B3305H. Link here (PDF) Holtek has released a CAN Bus interface control device, the HT45B3305H. The CAN physical layer can support high-speed networks up to 1 Mbit/s and supports the CAN 2.0A/B protocol as well as conforming to the ISO11898-1:2003 specification. It has 32 internal channels (Message Objects) and provides data transmission and a Received Enhanced Full CAN architecture as well as SPI and I2C communication interfaces.

[Category: app notes, app note, CAN-bus, Holtek]

[*] [+] [-] [x] [A+] [a-]  
[l] at 5/28/23 11:00am
App note from Abracon about EMI filtering with CMCs. Link here Common mode chokes are used in both power and signaling circuits. Data lines in electronic communications systems usually exist as pairs where they transmit signals of equal amplitude but opposite polarity. These lines are known as differential signals or pairs, such that the transmitted signal is sensed at the receiver by taking the voltage difference between the two lines. A common mode choke is a passive electromagnetic device that permits the passage of the desired electrical signals through data or power lines while filtering out the unwanted high-frequency noise signal from external sources or other circuits of the system.

[Category: app notes, abracon, app note, EMI suppression]

[*] [+] [-] [x] [A+] [a-]  
[l] at 5/28/23 7:00am
Aimtecs App note on addressing product failures caused by Tin whiskers. Link here Tin whiskers are slim metallic filaments that emanate from the surface of tin plating. As they are conductive, they can cause shorts across adjacent conductors which could result in failure. Whiskers occurs due to the presence of compressive stress or so called “stress gradient”. This compressive stress drives the preferential diffusion of tin atoms. For whiskers to form and grow, there must be more things present, but in the absence of such stress, they will not occur. The conditions of the surrounding environment (ambient temperature, thermal cycling, elevated humidity, and bending) simply initiates or accelerates the stresses present within the plating.

[Category: app notes, Aimtec, app note, tin whiskers]

[*] [+] [-] [x] [A+] [a-]  
[l] at 5/21/23 11:24am
A Fluke article about back-up batteries health. Link here Healthy batteries should maintain a capacity above 90 % of the manufacturer’s rating; most manufacturers recommend replacing the battery if it falls below 80 %.

[Category: app notes, app note, battery, Fluke]

[*] [+] [-] [x] [A+] [a-]  
[l] at 5/21/23 7:23am
Flukes article about safety from arc flashes. Link here The arc flash boundary is the minimum “safe” distance from exposed energized conductors or circuit parts that has the potential for an arc flash. Arc fault incidents happen daily in the United States. Take the proper steps to ensure your safety before taking any measurements, especially on energized equipment. Know where the arc flash boundaries are and keep these top safety measures in mind.

[Category: app notes, app note, Fluke, safety]

[*] [+] [-] [x] [A+] [a-]  
[l] at 5/14/23 11:00am
Things to look for and avoid when designing with IGBT devices discussed in this app note from Onsemi. Link here (PDF) This application note describes some of the impacts of the gate-emitter voltage on the IGBT device performance. Unlike the MOSFETs and BJTs, the magnitude of the gate-emitter supply voltage of an IGBT has a more significant impact on the performance of the device. The magnitude of the gate-emitter voltage impacts the turn-on loss and short circuit survival capability of the devices.

[Category: app notes, app note, IGBT, ONSEMI]

[*] [+] [-] [x] [A+] [a-]  
[l] at 5/14/23 7:00am
App note with sample circuit from Onsemi about thyristor replacing mechanical relays for AC line control. Link here (PDF) In the large family of electronic switches, the thyristor must be considered as a low cost and powerful device for motor applications. Thyristors can take many forms, but they have certain features in common. All of them are solid state switches which act as open circuits capable of withstanding the rated voltage until triggered. Because Thyristors are reliable solid state switches, they have many applications, especially as controls. A useful application of triac is as a direct replacement for an AC mechanical relay.

[Category: app notes, app note, ONSEMI, Relays and triacs]

[*] [+] [-] [x] [A+] [a-]  
[l] at 5/7/23 11:00am
Audio app note from Diodes Incorporated about the tiny PAM8908 audio line driver that streamlines driving a small load speakers in single rail power supply. Link here (PDF) The DIODES PAM8908 stereo headphone driver is designed for portable equipment where board space is at a premium. The PAM8908 uses a patented unique architecture to produce a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, board space, and component height. The PAM8908 delivers up to 25mW per channel into a 16Ω load and has low 0.03% THD+N. A high power-supply rejection ratio allows this device to operate from noisy digital supplies without an additional linear regulator. The PAM8908 operates from a single supply from 2.5V to 5.5V, has short-circuit and overtemperature protection. Shutdown mode reduces supply current to less than 1μA.

[Category: app notes, app note, audio amplifier, diodes incorporated]

[*] [+] [-] [x] [A+] [a-]  
[l] at 5/7/23 7:35am
App note from Vishay demonstrating a circuit to power IoT sensors with energy storage capacitors. Link here (PDF) The V-harvester board is a photovoltaic (PV) harvesting backup demonstration circuit. It is a sophisticated stand-alone board charged using TEMD5080X01 micro PV cells or with micro USB. The input power goes into an e-peas low power AEM10941 controller, where it is stepped up to the supercapacitor voltage of 4.2 V. Upon power demands at the interface or ENLV, ENHV settings, the controller converts the supply voltage to the target voltages using low dropout regulators (LDO).

[Category: app notes, app note, Enerygy Capacitors, solar energy, super capacitor, vishay]

[*] [+] [-] [x] [A+] [a-]  
[l] at 4/30/23 7:56am
App note from NXP providing information about the i.MX RT industrial drive development platform and how it utilizes the NAFE11388 Analog Front-End (AFE) to measure temperature used for fault detection. Link here (PDF) The NAFE11388 is a highly configurable industrial-grade multi-channel analog input AFE that meets highprecision measurement requirements. The device integrates dual low-leakage high-voltage fast multiplexers, low-offset and low-drift Programmable-Gain Amplifier (PGA) and buffers, a precision and high data rate 24-bit sigma-delta Analog-to-Digital converter (ADC), and low-drift voltage reference. The analog High Voltage (HV) input pins are internally diode-protected for Electromagnetic Compatibility (EMC) and misuse wire scenarios.

[Category: app notes, app note, industrial monitoring system, NXP]

[*] [+] [-] [x] [A+] [a-]  
[l] at 4/23/23 11:00am
App note from Coilcraft about electromagnetic interference and its unintention emission and regulation when comes to consumer products. Link here (PDF) Everyone enjoys the advantages of electronic devices and gadgets becoming smaller, lighter, and faster, while providing longer battery life and ever-improving processing ability. Smaller devices require smaller electronic components an advantage in reducing electromagnetic interference (EMI). However, a compact design also means smaller spacing between components, circuit traces, and enclosures, which can lead to increased field interactions, current loops, ground loops, cross-talk, and other potential sources of EMI. EMC is verified by testing to industry standards developed by regulating agencies described later in this discussion. These standards define specific test conditions and limits of noise emissions that may vary by location, application, and operating environment.

[Category: app notes, app note, Coilcraft, electromagnetic interference]

[*] [+] [-] [x] [A+] [a-]  
[l] at 4/23/23 7:12am
App note from Coilcraft all about Balance to Unbalance or Balun. Link here (PDF) A symmetrical balanced line has two conductors having equal current in opposite (differential) directions. Twisted pair cable and ribbon cable are examples of balanced line cables. An asymmetrical unbalanced (single-ended) line has one conductor connected to ground, such as coaxial cable. When a balanced source is to be isolated from an unbalanced load, the impedance matching transformer is referred to as a balun. If the impedance of the load matches that of the source, impedance matching is not required, and the balun has a 1 :1 impedance ratio. When the load impedance is mismatched to the source in a 1 :N impedance ratio, a 1 :N impedance ratio transformer is required.

[Category: app notes, app note, balun, Coilcraft]

[*] [+] [-] [x] [A+] [a-]  
[l] at 4/16/23 11:00am
Littelfuse cheat sheet on all varistors related. Link here (PDF) Transient suppressors can be exposed to high currents for short durations in the nanoseconds to millisecond time frame. Littelfuse Varistors are connected in parallel to the load, and any voltage drop in the leads to the varistor will reduce its effectiveness. Best results are obtained by using short leads that are close together to reduce induced voltages and a low ohmic resistance to reduce I • R drops.

[Category: app notes, app note, Littelfuse, transient voltage, varistor]

[*] [+] [-] [x] [A+] [a-]  
[l] at 4/16/23 7:09am
App note about controlling NKKs smart display, NKK provides compact push buttons with integrated display. Link here (PDF) The LCD 3624 SmartDisplay is currently available as 3624 standard pushbuttons, 3624 compact pushbuttons and 3624 displays. The pushbuttons and displays have a variety of options for backlighting.

[Category: app notes, app note, LCD interfacing, NKK, push-button]

[*] [+] [-] [x] [A+] [a-]  
[l] at 4/2/23 11:03am
Nexperias app note for multiphase machines. Link here (PDF) This application note describes the advantages of multiphase machines and prompts the reader to their recent, widely expanded usage. A short description of the power MOSFET switch design in is given, relying heavily on the more descriptive design. A short description of the control method for multiphase PMSMs is given with emphasis on the difference between threephase and multiphase machine control. The differences in the control method lays mostly in the transformation matrices.

[Category: app notes, app note, nexperia, servo motors]

[*] [+] [-] [x] [A+] [a-]  
[l] at 4/2/23 7:35am
App note from Nexperia that presents their LSF010x voltage level translator which uses parallel channels of pass transistors. Link here (PDF) System level designers are confronted with increasing complexity of modern electronic systems in which lower power and logic voltage levels are used. This may lead to incompatibility between input and output levels if different interface voltage are required within a system. The level shifters can have different input/output (I/O) voltage levels on A and B port side which allows safe communication between various devices without damage from overvoltage or malfunction due to improper high-state levels at the higher voltage side.

[Category: app notes, app note, nexperia, voltage translation]

[*] [+] [-] [x] [A+] [a-]  
[l] at 3/26/23 7:00am
Understanding the known factors of LEDs to help evaluate LED system lifetime discussed in this white paper from Lumileds. Link here (PDF) One of the strongest propositions of power Light Emitting Diodes (LEDs) is their long lumen maintenance their ability to continue producing light output for many years of use, in contrast to most conventional light sources, which force users to go through repeated and frequent failure-and-replacement cycles. The market perception of an LED’s reliability is reinforced by the widespread practice among lighting manufacturers of offering long warranties on their LED luminaires.

[Category: app notes, app note, LED, led lighting, Lumileds]

[*] [+] [-] [x] [A+] [a-]  
[l] at 3/19/23 11:00am
App note from Richtek on the comparison of current sensing methods using inductors DCR. Link here (PDF) Current sensing plays an important role in DC/DC regulator systems, especially in multi-phase buck converters for CPU VCORE applications. In VCORE applications, the current signals are used to decide the load-line droop, per-phase current balance, current reporting, and over current protection. Moreover, if the control topology is current mode, the current signal will directly affect the system stability. Therefore achieving accurate current signals is very important. Generally, the inductor DC resistance (DCR) current sensing technique is widely used in CPU voltage regulator (VR) applications due to its lossless characteristic. However, the DCR current sensing method needs to parallel an RC network beside the inductor, and is likely to be near noisy nodes like the phase node or other PWM signals. It offers many opportunities to add noise which may decrease the current sensing accuracy. In addition, the offset and bandwidth of the current sensing op amp can also decrease the sensed current signal accuracy or distort the current signal, and generally present a great challenge to acquiring a clean current signal.

[Category: app notes, app note, Current sensing, Richtek]

[*] [+] [-] [x] [A+] [a-]  
[l] at 3/19/23 7:00am
App note from Richtek about thermal resistance calculation using component thermal parameters found on datasheets. Link here (PDF) Thermal issue has been a crucial topic for a long time since high power density and low cost requirements became popular. As a power engineer, the assessment of maximum allowable power dissipation of every component in the system is one of the most important topics when developing a brand new product with good reliability. Generally, each component has a specific thermal characteristics table, which can be found in the datasheet. There are many thermal resistance listed in the table, including θJA, θJB, θJC…etc.

[Category: app notes, app note, Richtek, Thermal resistance]

[*] [+] [-] [x] [A+] [a-]  
[l] at 3/12/23 11:00am
App note from Nexperia on how MOSFETs imperfection can cause imbalance current when paralleled, and how these problems are solved. Link here (PDF) In today’s automotive and power industries, higher power requirements are leading to more designs that require lower RDSon. Sometimes this is not achievable with a single packaged MOSFET and the design will need to make use of two or more devices in parallel. Higher power applications could also require the use of high performance substrates like heavy copper PCB, IMS (Insulated Metal Substrate) or DBC (Direct Bonded Copper) and even bare dies. By paralleling, the total current and thus dissipation is shared between each device. However, this is not as simple as applying Kirchhoff’s current law: MOSFETs are not identical and thus they don’t share equally.

[Category: app notes, app note, MOSFETS, nexperia]

As of 6/5/23 11:38am. Last new 6/4/23 7:28am.

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