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Reducing Switching Losses and Increasing Efficiency, Devices Combine Low Qrr Down to 105 nC and VF Down to 1.45 V With Low Junction Capacitance, Fast Recovery Time, and Minimum Creepage Distance of 5.4 mm.

Vishay Intertechnology, Inc. expands its Gen 7 platform of 1200 V FRED Pt Hyperfast rectifiers with six new devices in the eSMP series SMPC HV package. Optimized for industrial, automotive, and energy applications, the 1 A, 2 A, and 3 A rectifiers not only offer the best trade-off between reverse recovery charge (Qrr) and forward voltage drop for devices in their class, but also provide the lowest junction capacitance and recovery time.

The Vishay Semiconductors rectifiers release include the VS-E7SX0112-M3V, VS-E7SX0212-M3V, and VS-E7SX0312-M3V, and AEC-Q101 qualified VS-E7SX0112HM3V, VS-E7SX0212HM3V, and VS-E7SX0312HM3V. To reduce switching losses and increase efficiency, the devices combine a fast recovery time of 50 ns with Qrr down to 105 nC typical, forward voltage drop down to 1.45 V, and junction capacitance down to 7.25 pF. The robust rectifiers offer non-repetitive peak surge current up to 70 A in a compact package measuring 4.3 mm x 6.5 mm with a low 1.1 mm profile, which is footprint-compatible with the TO-277A. Combined with a minimum 5.4 mm creepage distance and molding compound with a comparative tracking index (CTI) ≥ 600 (Material Group I), the devices reduce component counts and lower BOM costs based on IEC 60664-1 requirements for high voltage applications.

The VS-E7SX0112-M3V, VS-E7SX0212-M3V, VS-E7SX0312-M3V, VS-E7SX0112HM3V, VS-E7SX0212HM3V, and VS-E7SX0312HM3V will serve as clamp, snubber, and freewheeling diodes in flyback auxiliary power supplies and high-frequency rectifiers for bootstrap driver functionality, while providing desaturation protection for the latest fast-switching IGBTs and high-voltage Si / SiC MOSFETs. Typical applications for the devices include industrial drives and tools, on-board chargers and motors for electric vehicles (EV), energy generation and storage systems, and Ćuk converters and industrial LED SEPIC circuitry.

The rectifiers feature a planar structure and platinum-doped lifetime control that guarantee system reliability and robustness without compromising on performance, while their optimized stored charge and low recovery current minimize switching losses and reduce power dissipation. RoHS-compliant and halogen-free, the devices feature a Moisture Sensitivity Level of 1 in accordance with J-STD-020 and offer high temperature operation to +175 °C.

 

Device Specification Table:

Part #	IF(AV) (A)	VR (V)	VF at IF (V)	trr (ns)	Qrr (nC)	CT (pF)	IFSM (A)	Package	AEC-Q101
VS-E7SX0112-M3V	1	1200	1.45	50	105	7.25	19	SMPC HV	No
VS-E7SX0112HM3V	1		1.45		105	7.25	19		Yes
VS-E7SX0212-M3V	2		1.6		165	9.0	21		No
VS-E7SX0212HM3V	2		1.6		165	9.0	21		Yes
VS-E7SX0312-M3V	3		1.45		240	20	70		No
VS-E7SX0312HM3V	3		1.45		240	20	70		Yes

Samples and production quantities of the new Gen 7 rectifiers are available now, with a lead time of eight weeks.

The post Vishay Intertechnology Releases New 1 A, 2 A, and 3 A Gen 7 1200 V FRED Pt Hyperfast Rectifiers in SMPC HV Package appeared first on ELE Times.

Circuits for converting 4 to 20mA analog current loop signals to 0 to 20mA may be hot topics, but hot implementations of those circuits are not.

Circuit designs for conversion of 4 to 20mA analog current loop signals, which are ubiquitous in process monitoring and control, to 0 to 20mA are a hot topic recently.  “Hot topic” is a perfect description because typical examples of such converters can dissipate half a Watt.  Some cook even hotter than that!  This results in some very un-green complications like TO220 packaged power pass transistors sporting substantial heatsinks.  Would Greta T. approve?  I think not!

Wow the engineering world with your unique design: Design Ideas Submission Guide

The design in Figure 1 offers a cool (and maybe even useful) efficiency improvement.  It thriftily recycles most of the 4 to 20mA input current to generate the 0 to 20mA output while needing only microamps from its own local power supply.  It consumes merely 250uA x 24v = 6mW (typical) and dumps only similar single-digit milliwatts from Q2 (which is the closest thing it has to a pass transistor).  That’s not even enough heat to make a TO92 tepid.

Here’s how it works:

Figure 1 This circuit’s operation is governed by the following equation: Iout = Iin – 4mA(1 – (Iin – 4mA)/16mA))  = 1.25(Iin – 4mA). The maximum current drawn from the local V+ supply is only 1/80th of max Iout, translating to an 80:1 efficiency gain. Asterisked resistors are 0.5% precision or better.

The 4 to 20mA input current (99.95% of it, to be precise) passes through current sense resistor R1 and from there to the load, generating 200mv to 1v as Iin goes from 4 to 20mA.  The voltage to current converter R1+A1+Q1 makes that into Ic1 = Iin R1/R2 = 2uA to 10uA as the input to current to voltage converter R5+A2+Q2+R4, generating 0.5 to 2.5v across R5.  A2 compares this to A3’s 2.50v internal reference, forcing Q2 to conduct so that the sum Vr4 + Vr5 = 2.5v.

Thus Ic2 = (2.5 – Vr5)/R4 and it decreases linearly from 4mA to zero as Iin increases from 4 to 20mA. The net effect is to force Q2 to subtract a linearly decreasing 4 to 0mA from Iin, so that its 4 to 16mA span is corrected to 0 to 20mA in Iout. In other (mathspeak) words:  Iout = Iin – 4mA(1 – (Iin – 4mA)/16mA)) = 1.25(Iin – 4mA)

The payoff is that 98.8% of Iout comes from recycled Iin instead being sucked anew from V+.

V+ isn’t critical and needs only be sufficient to provide the compliance required by the (grounded) load.  R3 needs to provide 50uA bias for the A3pin3 shunt reference, so R3 = (V+ – 2.5)/50uA = 390k for V+ = 24v. Noncritical Z1 provides a few volts of headroom for the transistors.   The total voltage drop from input to output is 5.6v.

Finally, there’s a caveat.  In the event of complete loss of the nominal 4 to 20mA input current, A2 will drive Q2 into saturation.  This won’t damage anything, but will force A2 to draw 5mA from V+ to supply the required Q2 base current.

Stephen Woodward‘s relationship with EDN’s DI column goes back quite a long way. Over 200 submissions have been accepted since his first contribution back in 1974.  They have included best Design Idea of the year in 1974 and 2001.

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The post 4-20mA to 0-20mA converter sips mere microamps appeared first on EDN.

Materials, networking and laser technology firm Coherent Corp of Saxonburg, PA, USA has signed a letter of intent to receive up to $50m in direct funding under the CHIPS and Science Act from the US Department of Commerce to expand its 6-inch indium phosphide (InP) photonic device manufacturing facility in Sherman, Texas...

Materials, networking and laser technology firm Coherent Corp of Saxonburg, PA, USA has signed a letter of intent to receive up to $50m in direct funding under the CHIPS and Science Act from the US Department of Commerce to expand its 6-inch indium phosphide (InP) photonic device manufacturing facility in Sherman, Texas...

Phlux Technology — which was spun off from the University of Sheffield in 2020 and designs and manufactures 1550nm avalanche photodiode (APD) infrared (IR) sensors — has announced beta-sample availability of the Apex 200µm receiver module, PX02200-TO, for ultra-low-light detection as part of a family of Apex receivers that combine Phlux’s Noiseless InGaAs Aura APD detectors with low-noise, optimized pre-amplifier circuits all integrated in an industry-standard TO-8, 12-pin header package...

Phlux Technology — which was spun off from the University of Sheffield in 2020 and designs and manufactures 1550nm avalanche photodiode (APD) infrared (IR) sensors — has announced beta-sample availability of the Apex 200µm receiver module, PX02200-TO, for ultra-low-light detection as part of a family of Apex receivers that combine Phlux’s Noiseless InGaAs Aura APD detectors with low-noise, optimized pre-amplifier circuits all integrated in an industry-standard TO-8, 12-pin header package...

As quantum technologies move towards commercial deployment, the need to accelerate UK research into scalable, real-world deployment is increasingly critical. In response, the UK’s Compound Semiconductor Applications (CSA) Catapult has appointed as head of quantum, helping to accelerate its focus on key areas including quantum systems, AI hardware, advanced packaging, photonics, RF control, William Waller cryogenic integration and test. These capabilities are central to enabling the next generation of quantum technologies, particularly in quantum communications, quantum sensing and future quantum computing infrastructure, where integration, reliability and scalability will be essential...

As quantum technologies move towards commercial deployment, the need to accelerate UK research into scalable, real-world deployment is increasingly critical. In response, the UK’s Compound Semiconductor Applications (CSA) Catapult has appointed as head of quantum, helping to accelerate its focus on key areas including quantum systems, AI hardware, advanced packaging, photonics, RF control, William Waller cryogenic integration and test. These capabilities are central to enabling the next generation of quantum technologies, particularly in quantum communications, quantum sensing and future quantum computing infrastructure, where integration, reliability and scalability will be essential...