Tag Archives: MOSFET

Integrated Load Switches versus Discrete MOSFETs

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]

InGaAs TFET, a potential alternative to MOSFET in future ultralow power chips

by Graham Prophet @ edn-europe.com:

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.

A 400W (1kW Peak) 100A Electronic Load Using Linear MOSFETs

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]

LT8390 – 60V Synchronous 4-Switch Buck-Boost Controller with Spread Spectrum

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The LT8390, is a synchronous buck-boost DC/DC controller that can regulate output voltage, and input or output current from input voltages above, below and equal to the output voltage. Its 4V to 60V input voltage range and 0V to 60V output voltage range are ideal for voltage regulator, battery and supercap charger applications in automotive, industrial, telecom and even battery-powered systems. The LT8390’s 4-switch buck-boost controller, combined with 4 external N-channel MOSFETs, can deliver from 10W to over 400W of power with efficiencies up to 98%. Its buck-boost capability is ideal for applications such as automotive, where the input voltage can vary dramatically during stop/start, cold crank and load dump conditions. Transitions between buck, buck-boost and boost operating modes are seamless, offering a well regulated output even with wide variations of supply voltage. The LT8390 is offered in either a 28-lead 4mm x 5mm QFN or thermally enhanced TSSOP to provide a very compact solution footprint. [source]

LT8390 – 60V Synchronous 4-Switch Buck-Boost Controller with Spread Spectrum – [Link]

Load switch with self-resetting circuit breaker

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has designed a simple load switch using two transistors and some resistors.

The simple current-limiting load switch shown in Figure 1 will be familiar to most readers. In this circuit, a high level signal applied to the input switches on MOSFET Q2, which energizes the load. The load current is limited by negative feedback applied via Q1.

Load switch with self-resetting circuit breaker – [Link]

The new 800V CoolMOS MOSFET from Infineon

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Thomas Scherer @ elektormagazine.com shares the news about a CoolMOS Mosfet from Infineon.

The latest 800V CoolMOS P7 800V MOSFET from Infineon is based on their superjunction technology. The device is available in twelve classes of RDS(on) beginning with  0.28 Ω and in six package options. It is particularly suited to high voltage switching applications, flyback applications including adapter and charger, LED lighting, audio SMPS, AUX and industrial power.

The new 800V CoolMOS MOSFET from Infineon – [Link]

FemtoFET – 20V 500mA 0.6×0.7mm MOSFET From TI

Texas Instruments “TI” recently announced  FemtoFET series.
There are N-channel MOSFETS like CSD15380F3 and P-channel MOSFETS like CSD25480F3 and CSD23280F3 in this series. These transistors are SMD (Surface Mount Devices) available in a very small package, the land grid array (LGA) package.

Traditional SOT-23 package next to the CSD18541F5 LGA package. Image Source: TI
Traditional SOT-23 package next to the CSD18541F5 LGA package. Image Source: TI

To explore this family we will highlight the FemotoFET MOSFET CSD15380F3. It has a 20V Vds, 990 mohm Rds @ Vgs=8, 500mA maximum Id, 0.5W power dissipation and ultra-small LGA Footprint 0.73 mm × 0.64 mm which make it suitable for many handheld and mobile applications.

Pin-out of CSD15380F3
Pin-out of CSD15380F3
LGA Package
LGA Package

The new MOSFET has Qg = 0.216 nC Ultra-low capacitance and that improves switching speeds in data line applications.

Table Source: Product Page
Table Source: Product Page

It’s available on Mouser for 0.47$ for 1 unit order and 0.05$ for 1,000 unit order and need 6 weeks lead time.
Via: TI E2E Community Blog

App note: Solid-State Relays

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Solid-state relays introduction from Vishay, (PDF)

MOSFET SSRs feature an optocoupler construction, but have a pair of MOSFETs on the output instead of a phototransistor. A pair of source-coupled MOSFETs emulate an electromechanical relay by providing bidirectional switch capability and a linear contact. No output power supply is required.

App note: Solid-State Relays – [Link]

High Current Discrete Half-Bridge Based on IR2104 or IR2101

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This is a discrete Half-bridge driver based on IR2104 gate driver IC and low impedance high current N channel IRFP4368 MOSFETS. The IR2104 is a high voltage, high speed power MOSFET driver with independent high and low side referenced output channels. HVIC and latch immune CMOS technologies enable ruggedized monolithic construction. The logic input is compatible with standard COMOS or LSTTL output, down to 3.3V logic. A gate IR2104 driver is a power amplifier that accepts a low-power input from a controller IC and produces a high-current drive input for the gate of a high-power transistor such as a power MOSFET. In essence, a gate driver consists of a level shifter in combination with an amplifier.

This drive has many application, ranging from DC-DC power supply for high power density and efficiency, This project simplifies the design of control systems for a wide range of motor applications such as home appliances, industrial drives, DC brushed motors , Brushless motors, fans, Tesla Coil driver, Induction coil driver, LED driver, Halogen Lamp driver.

High Current Discrete Half-Bridge Based on IR2104 or IR2101 – [Link]

DIY 1GHz Active Probe For Under 20$

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thirschbuechler @ instructables.com shows us how to build a 1GHz active probe using BF998 dual-gate MOSFET and some other RF components.

This Instructable will show you how to build a 1GHz* Fet-based Active Probe, the Fetprobe, for about 10$*, provided you have access to an electronics lab. It is based on an Elektor-magazine article (see the pdf’s addendum, section literature in my thesis) beside some other designs. However, as topic of my bachelor-thesis I wanted to find out how good these designs really are and how far one can push them.

DIY 1GHz Active Probe For Under 20$ – [Link]