Friday, October 14, 2016

High Efficiency Step Down Isolated Supply

60W AC-DC adapter, synchronous rectification, fixed frequency current mode PWM controller. Very Low Quiescent Burden, Efficiency above 85%. That's Green.

STMicroelectronics - EVALSTSR30-60W. Synchronous rectification using L6668 and STSR30.

EVALSTSR30-60W: 60W AC-DC adapter
EVALSTSR30-60W: 60W AC-DC adapter

The converter works in both Continuous and Discontinuous conduction mode depending on the input voltage (the circuit has a wide input voltage range) and the output load. The 68-kHz switching frequency provides a good compromise between the transformer size and the harmonics of the switching frequency, optimizing input filter.

High Efficiency Step Down Isolated Supply

The input section includes protection elements (varistor, fuse and NTC for inrush current limiting), a standard Pi-filter for EMC suppression, a bridge and an electrolytic bulk capacitor as the front-end AC-DC converter. The transformer is a layer type, uses a standard ETD34 ferrite core and is designed to have a reflected voltage of 95V. The power MOS is a 700V - 1Ω and a transil clamp network is used for leakage inductance demagnetization.

From STMicroelectronics

Wednesday, October 12, 2016

EMI RFI - ElectroMagnetic Interference

Electromagnetic interference (or EMI, also called radio-frequency interference or RFI when in radio frequency) is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source.
Electromagnetic interference Wiki

Vertical polarized VHF- UHF biconical antenna

Vertical polarized VHF- UHF biconical antenna
170 – 1100 MHz with omni directional H-plane pattern

Who would know better about Radio Frequency Interference and ElectroMagnetic Interference more than the Hams or Amateur Radio Community.

If they have to communicate effectively using limited resources, they have to deal with EMI/RFI effectively, While they build their equipment or combat Noise from other Machines and Installations nearby.

This problem needs more practical involvement and experimentation to learn, compared to learning something like Digital Electronics.

Equipment and Electricals like SMPS, AC/DC Drives, Motors, Solenoids and CFL Lamps are to be built/reinforced for low EMI/RFI emission/radiation.

Sensitive Medical Equipment like ECG or even a Aircraft can be seriously affected by Noise.

Radio Frequency Interference (RFI)

Sunday, October 02, 2016

Rambus - IP Provider - Semiconductors

Technology licensing company. Manages and Provides Licenses to IP Intellectual property and Patents of semiconductor Technology. Founded in 1990.  XDR, DDR3, RDRAM and FlexIO are some of the Technology Solutions from Rambus.

Rambus - IP Provider - Semiconductors

"Beginning with edge-lit back lighting, Rambus has pioneered light guide-based design solutions for a broad range of LED lighting applications, enabling a new level of styling, efficiency and control of light."

LED lighting technology - Rambus

LED lighting technology

Rambus' lighting solutions enable manufacturers to use fewer or lower-cost LEDs in their general lighting products while delivering superior light quality and output.

Friday, August 12, 2016

NXP Semiconductors - Electronic IC Devices

NXP Semiconductors brings you a broad portfolio of advanced, trendsetting standard ICs products. they include standard and specialty Logic, I2C Logic, innovative Interface products, Microcontrollers, Analog, and RF.

NXP Semiconductors - Electronic IC Devices

They also have Discrete and Power Semiconductors like MOSFETs, Thyristors, Bipolar transistors and even Diodes.

NXP creates semiconductors, system solutions and software that deliver better sensory experiences in mobile phones, personal media players, TVs, set-top boxes, identification applications, cars and a wide range of other electronic devices.

Solutions in RF Identification, Power management Chips, Connectivity and for HandHeld Devices.

NXP (for Next eXPerience) Semiconductors is the name for the new semiconductor company founded by Philips.

ADC1x13DW1 Demo board from NXP

ADC1x13DW1 Demo board from NXP

"NXP's ADC demo board is suitable for dynamic performance evaluations from low to high IF configuration. The FPGA eases the evaluation and analysis of the ADC dynamic and enables use of the full JESD204A feature set"

Saturday, August 06, 2016

Analog Devices - Semiconductors and Signal Processing

They develop Analog Semiconductors, Digital Signal Processing, high performance signal processing solutions. Broadband Products, RF/IF Components, Embedded Processing and DSP.

Analog Devices - Semiconductors and Signal Processing

Products Include - Amplifiers, Processors, MEMS, A/D Converters, Temperature Sensors, RF Amplifiers, Differential Amplifiers, Thermal Management, D to A Converters, Microcontroller and Embedded Processing and DSP.

Circuit Note CN0147 - Powering a Fractional-N Voltage Controlled Oscillator (VCO) with Low Noise LDO Regulators for Reduced Phase Noise

Circuit Note CN0147 - Analog Devices

This circuit uses low noise, low dropout (LDO) linear regulators to supply power to a wideband integrated PLL and VCO. Wideband voltage controlled oscillators (VCOs) may have increased sensitivity to power supply noise, hence, ultralow noise regulators are recommended for best performance.

The evaluation board, which uses the ADP150 LDOs to power the ADF4350. The ADP150 represents the industry’s lowest noise LDO in the smallest package at the lowest cost.

Analog Devices, Inc
One Technology Way Norwood, MA 02062-9106, USA.

Monday, August 01, 2016

Data, Media and Telecommunications Standards

Wireless Communications now have voice, data, media. It has capability of the Internet, making a portable device part of the World Wide Web. There are companies and institutions that are making this utopia of a connected world possible with the systematic approach.

The Communications Network

Now with IoT, WSN and M2M a complexity arises. Robots, Drones, Automobiles and Machines have wireless connectivity with an IP address or a Phone Number. All this is possible when we think of technologies more like Wi-Fi and WiMax merging with mobile-cellular systems. We have to abandon the Towers and go for Modular Daisy Chain of Repeaters on Street Poles and Fiber Optic Nodes. Maybe like these folks say LightRadio Antenna Module

ETSI - European Telecommunications Standards - ETSI produces globally-applicable standards for Information and Communications Technologies (ICT). Includes - Fixed, mobile, radio, converged, broadcast and internet technologies.

ITU-T - Infocommunications Standards - "ITU-T Recommendations are defining elements in information and communication technology (ICT) infrastructure. Whether we exchange voice, data or video messages, communications cannot take place without standards linking the sender and the receiver. See " Telecommunication Standardization Bureau" TSB

CDG - 3G Wireless CDMA Development - "The CDMA Development Group (CDG), founded in December 1993, is an international consortium of companies who have joined together to lead the adoption and evolution of 3G CDMA wireless systems around the world." See also CDMA Technology

3GPP - Mobile Broadband Standard - "The original scope of 3GPP was to produce Technical Specifications and Technical Reports for a 3G Mobile System based on evolved GSM core networks …" Global System for Mobile communication (GSM), GPRS and EDGE.

IEEE - Broadband Wireless Access Standards - "The IEEE 802.16 Working Group on Broadband Wireless Access is creating the IEEE 802.16 family of WirelessMAN Standards for Wireless Metropolitan Area Networks."

Tuesday, July 12, 2016

Handbook of Operational Amplifier Applications

Here are two important educational reference books from Texas Instruments in PDF format.

"While in the process of reviewing Texas Instruments applications notes, including those from the recently acquired Burr-Brown - I uncovered a couple of treasures, this handbook on active RC networks and one on op amp applications. These old publications, from 1966 and 1963, respectively, are some of the finest works on op amp theory that I have ever seen. Nevertheless, they contain some material that is hopelessly outdated. This includes everything from the state of the art of amplifier technology, to the parts referenced in the document - even to the symbol used for the op amp itself:"

Handbook of Operational Amplifier Applications

Handbook of Operational Amplifier Applications - PDF
by Bruce Carter and Thomas R. Brown - sboa092a.pdf - 2.1 Mb

The operational amplifier is an extremely efficient and versatile device. Its applications span the broad electronic industry filling requirements for signal conditioning, special transfer functions, analog instrumentation, analog computation, and special systems design. The analog assets of simplicity and precision characterize circuits utilizing operational amplifiers.

Handbook of Operational Amplifier Active RC Networks - PDF
by Bruce Carter and L.P. Huelsman - sboa093a.pdf - 3.6 Mb

This is a handbook on active RC networks. The first question about this subject that one might ask is, "What is an active RC network?" The answer is simple. It is collection of resistors, capacitors, and an active element (or elements). Viewed in another sense; it is a circuit without inductors. Why leave out inductors? There are many reasons. First of all, the inductor is a relatively large and heavy element. This is especially true at frequencies in the audio range and below.