Mini Isolated Power Supply is designed for CAN, RS-485, RS-422, RS-232, SPI, I2C, Low-Power LAN applications. The power supply provides +/- 5.50 V DC symmetrical outputs with load current 500mA from 5V DC input. The project is built using SN6505A IC from Texas instruments. The SN6505A is a low-noise, low-EMI push-pull transformer driver, specifically designed for small form factor, isolated power supplies. It drives low profile, center-tapped transformers 5 V DC power supply. Ultra-low noise and EMI are achieved by slew rate control of the output switch voltage and through Spread Spectrum Clocking (SSC). The SN6505 consists of an oscillator followed by a gate drive circuit that provides the complementary output signals to drive ground referenced N-channel power switches. The device includes two 1-A Power-MOSFET switches to ensure start-up under heavy loads. The internal protection features include a 1.7A current limiting, under-voltage lockout, thermal shutdown, and break-before-make circuitry. SN6505 includes a soft-start feature that prevents high inrush current during power up with large load capacitors.
Isolated Power Supply for RS485, RS422, RS232, SPI, I2C and Power LAN – [Link]
The project is built for professional photo flash systems. Circuit generates high voltage from low voltage battery to operate a photo-flash tube. The project can also be used in other applications like high voltage capacitor charger, emergency strobe, high voltage power supply, security, detonators etc. LT3751 is the heart of the project.
The LT3751 is a high voltage input flyback controller designed to rapidly charge a large capacitor to a user-adjustable high target voltage set by the transformer turns ratio and three external resistors. Optionally, a feedback pin can be used to provide a low noise high voltage regulated output. The LT3751 has an integrated rail-to-rail MOSFET gate driver that allows for efficient operation down to 4.75V.
High Voltage Capacitor Charger for Photo-Flash Using LT3751 – [Link]
This tiny board designed to drive bidirectional DC brushed motor of large current. DC supply is up to 50V DC. A3941 gate driver IC and 4X N Channel Mosfet IRLR024 used as H-Bridge. The project can handle a load up to 10Amps. Screw terminals provided to connect load and load supply, 9 Pin header connector provided for easy interface with micro-controller. On board shunt resistor provides current feedback.
The A3941 is a full-bridge controller for use with external N-channel power MOSFETs and is specifically designed for automotive applications with high-power inductive loads, such as brush DC motors. A unique charge pump regulator provides full (>10 V) gate drive for battery voltages down to 7 V and allows the A3941 to operate with a reduced gate drive, down to 5.5 V. A bootstrap capacitor is used to provide the above-battery supply voltage required for N-channel MOSFETs. An internal charge pump for the high-side drive allows DC (100% duty cycle) operation.
50V – 10A Bidirectional DC Motor Driver Using A3941 – [Link]
This project made using MC3PHAC from NXP Semiconductor. The project generates 6 PWM signals for 3 Phase AC Motor controller. It’s very easy to make professional VFD combining with Intelligent Power Module (IPM) or 3 Phase IGBT/MOSFET with Gate driver. The board provides 6 PWM signals for the IPM or IGBT Inverter and also brake signal. Also this board works in stand-alone mode and doesn’t require any software programming/coding.
The MC3PHAC is a high-performance monolithic intelligent motor controller designed specifically to meet the requirements for low-cost, variable-speed, 3-phase ac motor control systems. The device is adaptable and configurable, based on its environment. It contains all of the active functions required to implement the control portion of an open loop, 3-phase ac motor drive. One of the unique aspects of this board is that although it is adaptable and configurable based on its environment, it does not require any software development. This makes the MC3PHAC a perfect fit for customer applications requiring ac motor control but with limited or no software resources available.
Included in the MC3PHAC are protective features consisting of dc bus voltage monitoring and a system fault input that will immediately disable the PWM module upon detection of a system fault.
A research group at Japan’s National Institute for Materials Science (NIMS) has developed logic circuits equipped with diamond-based metal-oxide-semiconductor field-effect-transistors (MOSFETs) at two different operation modes – a first step toward the development of diamond integrated circuits operational under extreme environments.
Is Diamond Suitable for this?
In fact, diamond has high carrier mobility, a high breakdown electric field and high thermal conductivity. Therefore, it is a promising material to use in the development of current switches and integrated circuits. Specifically to operate stably at high-temperature, high-frequency, and high-power. However, it had been difficult to enable diamond-based MOSFETs to control the polarity of the threshold voltage. In addition, fabricating MOSFETs of two different modes on the same substrate was a challenge. The modes are: a depletion mode (D mode) and an enhancement mode (E mode).
Thus, the research group has successfully developed a logic circuit equipped with modes. Thanks to threshold control technique that allowed them create hydrogenated diamond NOT and NOR logic circuits composed of D-mode and E-mode MOSFETs.
The LTC7003 is a fast high side N-channel MOSFET gate driver that operates from input voltages up to 60V. It contains an internal charge pump that fully enhances an external N-channel MOSFET switch, allowing it to remain on indefinitely. Its powerful driver can easily drive large gate capacitances with very short transition times, making it well suited for both high frequency switching applications or static switch applications that require a fast turn-on and/or turn-off time. When an internal comparator senses that the switch current has exceeded a preset level, a fault flag is asserted and the switch is turned off after a period of time set by an external timing capacitor. After a cooldown period, the LTC7003 automatically retries.
LTC7003 – Fast 60V Protected High Side NMOS Static Switch Driver – [Link]
In a recently published study, a team of researchers at SUNY Polytechnic Institute in Albany, New York, has suggested that combining multiple functions in a single semiconductor device can significantly improve device’s functionality and efficiency.
Nowadays, the semiconductor industry is striving to scale down the device dimensions in order to fit more transistors onto a computer chip and thus improve the speed and efficiency of the devices. According to Moore’s law, the number of transistors on a computer chip cannot exponentially increase forever. For this reason, scientists are trying to find other ways to improve semiconductor technologies.
To demonstrate the new technology which can be an alternative to Moore’s law, the researchers of SUNY Polytechnic designed and fabricated a reconfigurable device that can be a p-n diode (which functions as a rectifier), a MOSFET (for switching), and a bipolar junction transistor (or BJT, for current amplification). Though these three devices can be fabricated individually in modern semiconductor fabrication plants, it often becomes very complex if they are to be combined.
Ji Ung Lee at the SUNY Polytechnic Institute said,
We are able to demonstrate the three most important semiconductor devices (p-n diode, MOSFET, and BJT) using a single reconfigurable device. We can form a single device that can perform the functions of all three devices.
The multitasking device is made of 2-D tungsten diselenide (WSe2), a new transition metal dichalcogenide semiconductor. This class of materials is special as the bandgap is tunable by varying the thickness of the material. It is a direct bandgap while in single layer form.
Another challenge was to find a suitable doping technique as WSe2 lacks one being a new material. So, to integrate multiple functions into a single device, the researchers developed a completely new doping method. By doping, the researchers could obtain properties such as ambipolar conduction, which is the ability to conduct both electrons and holes under different conditions. Lee said,
Instead of using traditional semiconductor fabrication techniques that can only form fixed devices, we use gates to dope.
These gates can control which carriers (electrons or holes) should flow through the semiconductor. In this way, the ambipolar conduction is achieved. The ability to dynamically change the carriers allows the reconfigurable device to perform multiple functions. Another advantage of using gates in doping is, it saves overall area and enable more efficient computing. As consequence, the reconfigurable device can potentially implement certain logic functions more compactly and efficiently.
In future, researchers plan to investigate the applications of this new technology and want to enhance its efficiency further. As Lee said,
We hope to build complex computer circuits with fewer device elements than those using the current semiconductor fabrication process. This will demonstrate the scalability of our device for the post-CMOS era.
Alek Kaknevicius @ ti.com discuss about load switches and the advantages of intergrated switches over discrete ones.
The most common approach to load switching solutions is to use a Power MOSFET surrounded by discrete resistors and capacitors; however, in most cases using a fully integrated load switch has significant advantages. While both discrete and integrated load switching solutions perform the same basic function (turn on and turn off), distinctions exist, such as the transient behavior and total solution size. This application report highlights many drawbacks and limitations of a discrete switching solution and discusses how they can be overcome with an integrated load switch.
Integrated Load Switches versus Discrete MOSFETs – [Link]
Belgian researchers from imec, at a conference** dedicated to compound semiconductor technology, are to present promising device results with a InGaAs-only TFET (tunnel field-effect transistor) that achieves a sub-60 mV/decade sub-threshold swing at room temperature.
InGaAs TFET, a potential alternative to MOSFET in future ultralow power chips – [Link]
Kerry Wong built a 400W/100A electronic load using linear MOSFETs. He writes:
I bought a couple of IXYS linear MOSFETs (IXTK90N25L2) a while ago to test their capabilities when used as electronic load, and the result was quite impressive. So I decided to build another electronic load using both MOSFETs. As you can see in the video towards the end, this electronic load can sink more than 100 Amps of current while dissipating more than 400W continuously and can withstand more than 1kW of power dissipation in pulsed operation mode.
A 400W (1kW Peak) 100A Electronic Load Using Linear MOSFETs – [Link]