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]
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]
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]
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-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]
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]
In a paper published in Nature Communications researchers at IBM describe how they have built a silicon-based receiver chip incorporating GFETs or Graphene Field Effect Transistors (the purple structure in the photo) into the circuit. The multi-stage receiver integrated circuit consists of 3 graphene transistors, 4 inductors, 2 capacitors, and 2 resistors.
“This is the first time that someone has shown graphene devices and circuits to perform modern wireless communication functions comparable to silicon technology,”
said Supratik Guha, Director of Physical Sciences at IBM Research. In a test the team successfully used the graphene-based receiver to process a digital transmission on 4.3GHz. The binary sequence received was 01001001 01000010 01001101, which represents ASCII coding of the letters IBM.
IBM Chip uses Graphene FETs - [Link]
Industry’s Only 60V, 2.5A Internal FET Synchronous Buck Converter
The MAX17503 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 2.5A 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.
The device features a peak-current-mode control architecture with a MODE feature that can be used to operate the device in pulse-width modulation (PWM), pulse-frequency modulation (PFM), or discontinuous-conduction mode (DCM) control schemes. PWM operation provides constant frequency operation at all loads, and is useful in applications sensitive to switching frequency. PFM operation disables negative inductor current and additionally skips pulses at light loads for high efficiency. DCM features constant frequency operation down to lighter loads than PFM mode, by not skipping pulses but only disabling negative inductor current at light loads. DCM operation offers efficiency performance that lies between PWM and PFM modes. The low-resistance, on-chip MOSFETs ensure high efficiency at full load and simplify the layout.
4.5V-60V, 2.5A, High-Efficiency, Synchronous Step-Down DC-DC Converter with Internal Compensation - [Link]
TraId – is a Transistor type & pinout identifier:
TraId is a really low cost version of the Part Ninja. It’s made to only identify the pinout and type (NPN/PNP) of a transistor and display the results on eight LEDs. Currently the firmware only handles BJTs but I think FETs should be possible as well.
TraId – Transistor type & pinout identifier - [Link]
This DC-DC Converter start-up from as low as 330mV input! Marian Stofka writes:
The bq25504 from Texas Instruments is a good candidate to become a milestone on the road to micro-power management and energy harvesting. A prominent feature of this IC is its ability to start up at a supply voltage as low as 330 mV typically, and 450 mV guaranteed. With an SMD inductor and a few capacitors and resistors, it forms a dc-dc converter with a high power efficiency that is unprecedented, especially in the ultralow-power region.
DC-DC converter starts up and operates from a single photocell - [Link]