Tag Archives: FET

New flat transistor defies theoretical limit


by Bob Yirka @ techxplore.com:

A team of researchers with members from the University of California and Rice University has found a way to get a flat transistor to defy theoretical limitations on Field Effect Transistors (FETs). In their paper published in the journal Nature, the team describes their work and why they believe it could lead to consumer devices that have both smaller electronics and longer battery life. Katsuhiro Tomioka with Erasmus MC University Medical Center in the Netherlands offers a News & Views article discussing the work done by the team in the same journal edition.

New flat transistor defies theoretical limit – [Link]

Open Inverter, an open source micro-solar inverter


Ken Boak has been working on an open source micro-solar inverter project:

We wanted to make a design that uses readily obtainable N-type FETS and an Arduino (more strictly a ATmega328P-PU on a breadboard) to generate the PWM signals and provide simple circuit protection, and load sensing. With the PWM signals generated in firmware it can easily be modified for 50Hz or 60Hz operation, either 115V or 230V operation and a wide range of battery input voltages.
We imagined that the final design could consist of an Arduino, an “Inverter Shield” containing FETs and driver ICs configued in a H-bridge and some voltage and current monitoring circuits. To make the inverter a 12V or 24V battery (or PV panel) and a 12V (or 24V) torroidal transformer would be added.

Open Inverter, an open source micro-solar inverter – [Link]

4-GHz op amps achieve ultralow input bias current


The LTC®6268-10/LTC6269-10 is a single/dual 4GHz FET-input operational amplifier with extremely low input bias current and low input capacitance. It also features low input-referred current noise and voltage noise making it an ideal choice for high speed transimpedance amplifiers, and high-impedance sensor amplifiers. It is a decompensated op amp that is gain-of-10 stable.

It operates on 3.1V to 5.25V supply and consumes 16.5mA per amplifier. A shutdown feature can be used to lower power consumption when the amplifier is not in use.

4-GHz op amps achieve ultralow input bias current – [Link]

4.5V to 17V Input, 10-A Synchronous Buck Converter Optimized for Small Size and Low Output Voltage


PMP9194 uses the TPS54020 synchronous-buck SWIFT converter with integrated FETs to provide a 10A/1V solution in less than 22mmx12mm of total board space area. This reference design uses a small 1.1uH inductor, 2x100uF ceramic output capacitors, and small 0402 external components to save space. The device switches at 300kHz and acheives 87% peak efficiency from a 12V input to a 1V output. The TPS54020 is ideal for powering low-voltage, high-current DSPs and FPGAs, and can be synchronized 180 degrees out-of-phase with another TPS54020 to reduce input ripple.

4.5V to 17V Input, 10-A Synchronous Buck Converter Optimized for Small Size and Low Output Voltage – [Link]

GaN technology will transform the future

photo by ascatron.com
photo by ascatron.com

Alex Lidow @ edn.com:

For the first time in 60 years, a new higher-performance semiconductor technology is less expensive to produce than the silicon counterpart. Gallium nitride (GaN), has demonstrated both a dramatic improvement in transistor performance and the ability to be produced at a lower cost than silicon. GaN transistors have unleashed new applications as a result of their ability to switch higher voltages and higher currents faster than any transistor before. These extraordinary characteristics have ushered in new applications capable of transforming the future. But this is just the beginning.

GaN field effect transistors (FETs) are now available as discrete transistors and as monolithic half-bridges, with performance 10 times better than the best commercial silicon MOSFET. But what happens when many devices are integrated to create a system on a single chip? What happens when the performance of that chip is 100 times better than silicon?

GaN technology will transform the future – [Link]

Complete 5A step-down Regulator


by elektor.com:

The LTM4625 from Linear Technology is a switching mode μModule (micromodule) regulator in a tiny 6.25 mm × 6.25 mm × 5.01 mm BGA package. Like many of the newer regulator designs, the package includes the switching controller; power FETs, inductor and support components. Operating over an input voltage range of 4 V to 20 V (or 2.375 V to 20 V with an external bias supply) the LTM4625 supports an output voltage range of 0.6 V to 5.5 V, set by a single external resistor. Its high efficiency design delivers up to 5A continuous output current. Only bulk input and output capacitors are needed.

Complete 5A step-down Regulator – [Link]

PWM Based LED Driver


Elmars writes:

If anybody is interesed, I have posed a follow up to this original post with a simple PWM LED driver, adding an ATtiny85 mCU. The post includes schematic, board layout and code for the ATtiny85. I hav tested the circuit up to 22 volts without a current limiting resistor. The FET only needs a small heat sink. Efficiency can be further improved by replacing the LM358 with an RC/LM741. The LM741 has a much sharper rise and fall time than the LM358 when run at 2KHz, resulting in the FET spending less time as a resistor. (during the slow ramp/fall the FET acts as a resistor, generating heat)

PWM Based LED Driver – [Link]

High Speed Trans-impedance Amp


by elektor.com:

The single LTC6268 and dual LTC6269 FET-input op amps from Linear Technology feature a tiny (3 fA typical) input bias current at 25°C (peaking at 4 pA max over the entire –40°C to 125°C temperature range). Their input characteristics make them a good match for photodiode, photomultiplier and other applications using high impedance, high speed sensors. The low distortion output signal can be used by an A/D converter. A shutdown feature lowers power consumption when an amplifier is not in use.

High Speed Trans-impedance Amp – [Link]

Hydra-X10 and Hydra-X20 by Active-Semi Inc.

Hydra-X is a development platform which is feature-rich, scalable, and easy to use.

The Hydra-X is based on the Power Application Controller (PAC)™ family of ICs. Hydra-X gives you the ability to execute your own code on a 32-bit ARM Cortex core, paralleled with analog resources such as multi-mode power manager (for AC-DC, DC-DC power management), configurable Analog Front-End (AFE), data converters (1 MHz 10-bit ADC, 2 precision DACs), 52 V, 72 V, 600 V gate drivers, and open drain drivers, to name a few.

With up to 14 PWM timing functions, you will find it hard to run out of timing resources. Fully configurable into PWM, input capture or output compare, these timers are expanded by a dead time generator block; extremely useful when driving external FETs in a half H-Bridge configuration and a dead time needs to be imposed in order to protect the design from shoot-through.

Hydra-X10 and Hydra-X20 by Active-Semi Inc. – [Link]

MAX17505 – Industry’s Only 60V, 1.7A Internal FET Synchronous Buck Converter


by maximintegrated.com:

The MAX17505 high-efficiency, high-voltage, synchronously rectified step-down converter with dual integrated MOSFETs operates over a 4.5V to 60V input. It delivers up to 1.7A and 0.9V to 90%VIN output voltage. Built-in compensation across the output voltage range eliminates the need for external components. The feedback (FB) regulation accuracy over -40°C to +125°C is ±1.1%. The device is available in a compact (4mm x 4mm) TQFN lead(Pb)-free package with an exposed pad. Simulation models are available.

MAX17505  – Industry’s Only 60V, 1.7A Internal FET Synchronous Buck Converter – [Link]