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Circuit Cellar's editorial team comprises professional engineers, technical editors, and digital media specialists. You can reach the Editorial Department at editorial@circuitcellar.com, @circuitcellar, and facebook.com/circuitcellar

IoT Project: DIY, Net-Connected Wireless Water Heater

Some people like to remotely start their cars when it’s cold outside. Dan Beadle took this idea one step further by Internet-enabling his mountainside retreat’s hydronics system. The innovative design enables him to warm the house well in advance of his arrival.

Serving up the current temperature involves several computers, a Wi-Fi access point, and the DPAC Airborne module.

Serving up the current temperature involves several computers, a Wi-Fi access point, and a DPAC Airborne module.

In “Wireless Water Heater” (Circuit Cellar 163), Beadle writes:

My mountain home, where I have vacationed for years, is well insulated, making it a snap for the heater system to keep warm. I have a small, efficient heater; however, it takes forever to warm the house from a 50°F standby to a livable 68°F. Typically, I arrive late and shiver in my jacket for three or four hours until the house warms up—and that does not warm the entire house, just the portion needed to get through the night.

I had been thinking for a while about Internet-enabling the system. The idea was to turn on the heater before we start up the mountain. I have DSL at the house with a fixed IP. So, it seemed like it would be a simple task to enable a thermostat. I considered using an X10 thermostat, but, after a few of our X10-enabled lights found a mind of their own, I decided that I wanted better reliability. My next thought was to use simple copper to do the hook-up. I started planning a cable from my office/DSL entry up to the logical thermostat location. Then I procrastinated. I could not bring myself to run the wires along the surface of my redwood paneling. (And it was not at all feasible to remove the paneling.) Wireless makes the problem a lot simpler: there are no wires to run, and the applications processor and digital I/O on the module make the hardware design trivial.

Download the entire article.

 

New 32-Bit MCU Series for Embedded Control and Touch

Microchip Technology recently announced a new series within its PIC32MX1/2 32-bit microcontroller family that features a 256-KB flash configureation and 16-KB of RAM. The microcontrollers provide flexibility to low-cost applications that need complex algorithms and application code. More specifically, they are intended to help designers looking to develop products with capacitive touch screens or touch buttons, as well as USB device/host/OTG connectivity.Microchip PIC32mx1

The PIC32MX1/2 MCU series provides  up to 50 MHz/83 DMIPS performance for executing advanced control applications and mTouch capacitive touch sensing. In addition, it has an enhanced 8-bit Parallel Master Port (PMP) for graphics or external memory, a 10-bit, 1-Msps, 13-channel ADC, support for SPI and I2S serial communications interfaces, and USB device/host/On-the-Go (OTG) functionality.

Microchip’s MPLAB Harmony software development framework further simplifies designs by integrating the license, resale, and support of Microchip and third-party middleware, drivers, libraries and Real-Time Operating Systems (RTOS). Specifically, Microchip’s readily available software packages—including USB stacks and Graphics and Touch libraries—can greatly reduce the development time of applications such as consumer, industrial and general-purpose embedded control.

These latest PIC32MX1/2 MCUs are available now in 28-pin QFN, SPDIP ,and SSOP packages and 44-pin QFN, TQFP and VTLA packages. Pricing starts at $1.91 each, in 10,000-unit quantities.

Source: Microchip Technology

New Power MOSFETs Compact, Durable Electrical Appliances

Infineon Technologies recently extended its StrongIRFET Power MOSFET family. The Logic Level StrongIRFETs can be driven directly from a microcontroller, thus saving space and cutting costs. Additionally, the MOSFETs are highly rugged and thus help lengthen the service life of the electronic devices, such as DIY power tools (e.g., cordless drills) that have to be handy and durable.  Infineon Logic_Level_StrongIRFET

The StrongIRFET family enables high energy efficiency in electric appliances. With the logic level extension, Infineon meets the market’s demand for StrongIRFETs that do not require a stand-alone driver. In the logic level variant the necessary gate-source voltage is reduced to 4.5 V. Thus, you can directly connect the MOSFET with the microcontroller in many applications.

The characteristic performance features include: low on-state resistance (0.52 mΩ typical and 0.97 mΩ maximum) for reduced conduction losses, high current carrying capability for increased power capability, and rugged silicon all make for high system reliability.

Source: Infineon Technologies

Miniature 9.7 × 7.5 mm OCXO

IQD’s latest Oven-Controlled Crystal Oscillator (OCXO), the IQOV-71 series, is housed in four-pad plastic package with a fiber glass base. Despite it 9.7 × 7.5 mm size, it offers very low frequency stabilities down to ±10 ppb over an operating temperature range of –20° to 70°C or ±20 ppb over –40° to 85°C.IQD IQD0446-IQOV-71

The available standard frequencies include 10 MHz, 12.8 MHz, 19.2 MHz, 20 MHz, 24.576 MHz, 25 MHz, 30.72 MHz, 38.88 MHz, 40 MHz, 49.152 MHz, and 50 MHz, which will satisfy most applications. Other frequencies in the range of 5 to 50 MHz can be developed for commercially viable quantities. Power consumption is typically less than 1 W during the warm up phase, which only takes approximately 3 minutes, and less than 0.4 W once the device has reached steady state. Frequency aging is less than 2 ppb per day and a maximum of 3 ppm over a 10-year period.

The IQOV-71 offers either a standard HCMOS or Clipped sinewave output, with operating voltages specified at either 3.3 or 5 V. Low phase noise performance is assured with figures of –152 dBC/Hz at 10 kHz offset and only –153 dBc/Hz at 100 kHz from the carrier. The G-sensitivity is <2 ppb/G making the design suitable for applications such as military radios and airborn applications.

In order to maximize flexibility there is an option to specify external frequency adjustment by the application of a variable control voltage that allows for crystal ageing as well as changes in the circuit conditions. This variation is also extremely linear being less than 1% as against a more typical 5%.

This part is intended for a wide range of applications including picocells for the ever-increasing rage of wireless applications, satellite communication, broadcasting, microwave, and instrumentation, such as frequency counters and analyzers.

Source: IQD

New Battery Pack Monitor Protects Multi-Cell Li-ion Batteries

Intersil Corp. recently announced the ISL94203 3-to-8 cell battery pack monitor that supports lithium-ion (Li-ion) and other batteries. The ISL94203 can monitor, protect, and cell balance rechargeable battery packs to maximize battery life and ensure safe charging and system operation. It works as a stand-alone battery management system for rechargeable Li-ion battery packs.Intersil-ISL94203

The ISL94203’s internal state machine has five preprogrammed stages that accurately control each cell of a battery pack to extend operating life. In addition, it integrates high-side charge/discharge FET drive circuitry.

Notable features and specifications:

  • Highest level of integration
  • Eight cell voltage monitors support Li-ion CoO2, Li-ion Mn2O4, Li-ion phosphate and other battery chemistries
  • Can operate as a standalone solution or with a microcontroller
  • Integrated charge pump controls cutoff FETs used to charge/discharge battery pack
  • Multiple cell voltage protection options up to 4.8 V
  • Programmable detection/recovery times for over-voltage, under-voltage, over-current, and short circuit conditions
  • Open wire detection
  • EEPROM storage for device configuration
  • Power saving algorithm activated when battery pack is not in use

 

The ISL94203 battery pack monitor is available now through Intersil’s worldwide network of authorized distributors. The ISL94203 comes in a 6 mm × 6 mm, 48-lead TQFN package, and is priced at $2.19 in 1,000-piece quantities. The ISL94203EVKIT1Z evaluation kit ($328) includes an evaluation board, interface board with USB-to-I2C interface, and software GUI that supports stand-alone operation or an external microcontroller.

Source: Intersil Corp. 

A Real-World Look at Lighting

Living on a granite hill during a thunderstorm gave Circuit Cellar founder Steve Ciarcia new respect for Mother Nature. In a classic 1998 article, Steve described how he worked with Circuit Cellar columnist Jeff Bachiochi on a solution to automatically unhook their appliances when large storms hit.

Steve writes:

Without a source for a reasonably priced “thunderstorm switch,” Jeff and I decided to make one. Conceivably, all it would take is a lightning sensor, decision logic, and a means to connect and disconnect the attached equipment …

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An optically isolated pulse transmitter is connected to a low-cost McCallie Manufacturing lightning sensor mounted on a grounded pole on the roof.

The energy propagated from the current flow of a lightning strike contains wideband energy. Everything from 100 Hz to 100 MHz is produced. Emissions below 100 kHz travel along the wave guide formed by the earth’s surface and the lower ionosphere. With respect to the earth (ground), the air around the strike becomes charged, and there is a direct relationship between the amount of charge and the distance from the strike.

We located a minimum-cost lightning sensor from McCallie Manufacturing. Of the two models available, we chose the LSU2001, which is priced around $50. Simple circuits are also provided for adding a meter or LEDs to monitor live data, or you can connect the sensor through an optocoupler to a PC. Optional software lets you count and graph storm data (providing you wish to keep the PC on day and night).

The hits-per-minute converter also generates a “lightning alarm” output. This signal causes the circuit to physically disconnect the AC power, cable, and phone-line connections to the protected appliance.

The hits-per-minute converter also generates a “lightning alarm” output. This signal causes the circuit to physically disconnect the AC power, cable, and phone-line connections to the protected appliance.

The manufacturer suggests mounting the LSU2001 on a well-grounded metal pole. The higher above ground it’s mounted, the farther away you’ll be able to detect lightning strikes. Sensitivity is related to the differential charge between the air and ground—about 0.15 V/m. Put it twice as high, and it will be twice as sensitive.

Read the entire article from Circuit Cellar 90, 1998.

Blue Gecko Module Simplifies Smart Design

Silicon Labs recently introduced a fully integrated, precertified Bluetooth Smart module solution that provides a speedy path to low-power wireless connectivity for the IoT. The BGM111 module is the first in a family of advanced Blue Gecko modules delivering integration, flexibility, energy efficiency, and toolchain support with an easy migration path to Blue Gecko system-on-chip (SoC) solutions. It simplifies Bluetooth Smart design for a wide variety of applications ranging from smart phone accessories to industrial sensors.

Based on Silicon Labs’s Blue Gecko wireless SoCs, the 12.9 mm × 15 mm × 2.2 mm BGM111 modules provide a plug-and-play Bluetooth Smart design precertified for use in North America, Europe, and the Asia-Pacific. The BGM111 modules are preloaded with the Bluegiga Bluetooth 4.1-compliant software stack and profiles and are field-upgradable using device firmware upgrades to Bluetooth 4.2 and beyond.SiLabs BlueGeckoThe BGM111 module is supported by Silicon Labs’s wireless SDK, which means you can use either a host or fully standalone operation through the Bluegiga BGScript scripting language. Using a familiar BASIC-like syntax, BGScript enables you to create Bluetooth applications quickly without using external MCUs to run the application logic. All application code can be executed on the BGM111 module.

Pre-production samples of the BGM111 Blue Gecko module, supported by the SLWSTK6101A Blue Gecko wireless starter kit, are currently available. BGM111 module pricing begins at $4.97 in 10,000-unit quantities. The SLWSTK6101A starter kit costs $150.

Source: Silicon Labs

Radiation-Tolerant FPGA Kit

Microsemi recently announced the availability of the RTG4 FPGA Development Kit for high-bandwidth space applications. The innovative kit provides space designers an evaluation and development platform for applications such as data transmission, serial connectivity, and more.Microsemi RTG4-Dev Kit

The development kit provides all necessary reference to evaluate and adopt RTG4 technology quickly. You don’t need to build a test board and assemble the device onto the board. The RTG4 Development Kit is ideal for evaluating and designing for remote sensing space payloads, radar and imaging, and spectrometry. Other applications include mobile satellite services (MSS) communication satellites, high-altitude aviation, medical electronics, and civilian nuclear power plant control.

RTG4 FPGAs feature reprogrammable flash configuration, which makes prototyping easier. Reprogrammable flash technology offers complete immunity to radiation-induced configuration upsets in the harshest radiation environments, without the configuration scrubbing required with SRAM FPGA technology. RTG4 supports space applications requiring up to 150,000 logic elements and up to 300 MHz of system performance.

The RTG4 Development Kit’s features and specs:

  • One RT4G150 device in a ceramic package with 1,657 pins
  • Two 1GB DDR3 synchronous dynamic random access memory (SDRAM)
  • 2GB SPI flash memory
  • PCI Express Gen 1 interface
  • One pair SMA connectors for testing of the full-duplex SERDES channel
  • Two FMC connectors with HPC/LPC pinout for expansion
  • RJ45 interface for 10/100/1000 Ethernet
  • USB micro-AB connector
  • Embedded Flashpro5 programmer and external programming header
  • Current measurement test points

The RTG4 Development Kit features a RT4G150 device offering more than 150,000 logic elements in a ceramic package with 1,657 pins. Kits are available now for purchase.

Source: Microsemi

SWIFT DC/DC Buck Converters Reduce EMI

Texas Instruments recently launched the industry’s first 20-A and 30-A synchronous DC/DC buck converters with frequency synchronization for low-noise and reduced EMI/EMC and a PMBus interface for adaptive voltage scaling (AVS). The SWIFT 20-A TPS544B25 and 30-A TPS544C25 converters integrate MOSFETs and feature small PowerStack QFN packages to drive ASICs in space-constrained and power-dense applications. When used with TI’s WEBENCH online design tools, the converters simplify power conversion and speed the power supply design process. TI Swift

The highly integrated converters feature 0.5% reference-voltage accuracy, as well as full differential remote-voltage sensing. Frequency synchronization to an external clock eliminates beat noise and reduces EMI. Moreover, the TPS544B25 and TPS544C25 offer pin-strapping that enables the devices to start up without PMBus commands to an output voltage set by a single resistor. Programmability, real-time monitoring of the output voltage, current and external temperature, and fault reporting via PMBus simplify power-supply design, increase reliability, and reduce component count and system cost.

Together, the TPS544C25 and UCD90240 provide a complete PMBus point-of-load (POL) and sequencing solution. Download the Complete PMBus Power System for Enterprise Ethernet Switches TI Designs reference design.

TPS544B25 and TPS544C25 key features and benefits:

  • Integrated power MOSFETs support 20-A and 30-A of continuous output current.
  • On-chip PMBus interface and non-volatile memory simplify power-supply design and enable customization. Read a blog post on “PMBus – what is the value anyway?”
  • Voltage-control mode with input feed-forward improves noise margin and responds instantly to input voltage changes.
  • Other features include internal soft start, input under-voltage protection, thermal shutdown and a reset function.

The TPS544B25 costs $4.08 in 1,000-unit quantities. The TPS544C25 is $4.49 in 1,000-unit quantities. Evaluation modules are available.

Source: Texas Instruments

NXP’s New Automotive Ethernet Product Portfolio

NXP Semiconductors has launched product portfolio for automotive Ethernet that builds on BroadR-ReachT, which is an automotive standard defined by theOPEN Alliance industry group. NXP’s automotive portfolio features two product families: Ethernet transceivers (TJA1100) and Ethernet switches (SJA1105).

The Ethernet PHY TJA1100 supports automotive low power modes. The systems sleep when the engine is off. However, the Ethernet PHY stays partially powered and wakes up the system only when there is network activity.NXP_AutomotiveEthernet

Transceivers (TJA1100):

  • Compliant with the OPEN Alliance BroadR-Reach (OABR) standard (IEEE: 100BASE-T1)
  • Designed via an automotive development flow
  • 6 × 6 mm² HVQFN package with minimal external component count
  • Supports low-power modes to save battery life
  • Automotive grade ESD and EMC

NXP’s SJA1105 Automotive Ethernet Switch uses Deterministic Ethernet technology to guarantee message latency in applications such as autonomous driving, where deterministic communication is vital for reasons of operational efficiency or functional safety. Deterministic Ethernet supports the trend toward increasing bandwidth requirements of up to one gigabit, while ensuring high reliability in networked control systems and high availability in fail-operational applications. It comprises several standards, including Ethernet (IEEE 802.3), Time-Triggered Ethernet (SAE AS6802) as well as Audio Video Bridging (AVB), and Time-Sensitive Networking (TSN).

Digital Switch (SJA1105):

  • Five-port automotive Ethernet Switch supporting up to 1-Gb network speed
  • Layer 2 Store and Forward Switch
  • MII/RMII/RGMII Interface
  • Port Mirroring and VLAN support (IEEE 802.1Q and IEEE 802.1P)
  • AVB and TSN support
  • Enables Deterministic Ethernet solutions

TJA1100 Ethernet transceivers are available in prototype samples. They will enter mass production in late 2015. SJA1105  Ethernet Switches are available upon request.

Source: NXP Semiconductors

Find and Eliminate Ground Loops

Everything had been fine with my home entertainment center—comprising a TV, surround-sound amplifier, an AM/FM tuner, a ROKU, and a CD/DVD/BlueRay player—until I connected my desktop PC, which stores many of my music and video files on one of its hard drives. With the PC connected, the speakers put out a low level, annoying, 60-Hz hum—a clear indication of a ground loop. All my audio and video (AV) devices are fairly new, quality, brand-name products equipped with two-prong power cords, so even though the PC has a three-prong plug, there should not be multiple signal returns causing the ground loop. This article describes an approach to eliminating ground loops in analog AV systems.

GROUND LOOPS

By definition, ground loops bring about unwanted currents flowing through two or more signal return paths. Thus induction coils are formed, usually of one turn only. These loops pick up interference signals from the environment. Because every conductor has a finite impedance, a voltage potential—Vi = Ig(R1 + R2)—develops between the two connected signal return points. This voltage is the source of the interference: a hum, hiss noise that high-frequency signals pick up (e.g., a local AM station), and so forth. A simplified example is illustrated in Figure 1.

FIGURE 1: Cause of the ground loop interference.

FIGURE 1: Cause of the ground loop interference.

An audio signal source VS in Figure 1—an audio card inside the PC, for example—is connected to an amplifier via a shielded cable. The shield is grounded at both ends to the chassis of both devices. Three-prong power plugs connect the chassis of both AV components to the house power distribution ground wire. Let’s consider the amplifier ground to be the reference point. (It doesn’t matter which point in the loop we pick.) The loop, comprising the cable shield and the power distribution ground wire, picks up all kinds of signals causing loop current Ig to flow and as a result interference voltage Vi to be generated.

Vi is added to the signal from the audio card. The Ig current induced into the loop comes from many potential sources. It can be induced in the ground wire by the current flowing in the 120-VAC hot and its return neutral wires, acting like a transformer. There can be leakages, induction by magnetic fields, capacitive coupling, or an electromagnetic interference (EMI) induction into the loop. Once Vi is added to the signal it is generally impossible to filter it out.

Much of electrical equipment requires the third power prong for safety. This is connected to the chassis and at the electrical distribution panel to the neutral (white wire) and the local ground—usually a metal stake buried in the earth. The earth ground is there to dissipate lightning strikes but has no effect on the ground loops we are discussing.
The ground wire’s primary purpose is safety plus transient and lightning diversion to ground. Under normal circumstances no current should flow through this wire. Should an internal fault in an appliance connect either the neutral (white) or the hot (black or red) wire to the chassis, the green wire shunts the chassis to the ground. Ground fault interrupters (GFI) compare the current through the hot wire to the return through the neutral. If not identical, the GFI disconnects.

Manufacturers of audio equipment know that grounding sensitive equipment at different places along the ground wire results in multiple returns causing ground loops. These facilitate the interference noise to enter the system. From the perspective of electrical safety, the small currents induced in the ground loop can be ignored. Unfortunately, they are large enough to play havoc with sensitive electronics. The simplest solution to the dilemma is to avoid creating ground loops by not grounding the AV equipment. Thus the two-prong plugs have been used on such equipment. To satisfy the safety requirements, the equipment is designed with double insulation, meaning that even in case of an internal fault, a person cannot come to contact with a live metallic part by touching anywhere on the surface of the equipment.

My PC, like most desktops, has a three-prong plug. Figure 2 shows the arrangement. The PC is grounded through its power cord. Unfortunately, the cable TV (CATV) introduces a second ground connection through its coax connector. I measured the resistance between the coax shield as it entered the house and the house power distribution ground wire. The resistance was 340 mΩ, indicating a hard connection between the coax shield and the house ground, the cause of the ground loop. I was unable to establish where that connection was made, but it wasn’t through the earth.

FIGURE 2: Ground loop in my entertainment system

FIGURE 2: Ground loop in my entertainment system

There can be multiple ground loops around a computer system if you have hard-wired peripherals with three-prong plugs, such as some printers, scanners and so forth. Digital circuits are much less sensitive to ground loops than the analog ones, but it is a good idea to minimize potential loops by connecting all your peripherals, other than wireless, into a single power bar.

Ground loops may also be created when long shielded cables are used to interface the PC and the home theatre box. Two shielded cables needed for stereo represent two signal returns creating a ground loop of their own. And then there are video cables. Another loop. Fortunately, connectors on the back of the PC and AV equipment are very close to each other, which means a minimal potential difference between them at low frequencies. Stereo cables keep the loop small. To minimize all the loops’ areas for interference pick-up, I have bundled the interface cables very close to each other with plastic wire ties. In severe situations re-routing the cables or the use of a metal conduit or wireless interfaces may be needed to kill the interference.

FIXES

Having disconnected the CATV cable from the TV, the hum went away. As well, temporarily replacing the PC with a laptop, which is not grounded, also fixed the problem. So how else can we fix those offending multiple returns?

The obvious answer is to break the loop. I strongly suggest you don’t disconnect the PC from the ground by using a two-prong plug adapter or just cutting the ground prong off. It will render your system unsafe. What you need is a ground isolator. Jensen Transformers, for example, sell isolators such as VRD-IFF or PC-2XR to break the ground connection, but you can build one for a small fraction of the purchase price. Figure 3 and Figure 4 show you how.

FIGURE 3: Ground isolator for CATV coax

FIGURE 3: Ground isolator for CATV coax

To break the ground loop caused by the CATV, you can make a little gizmo shown in Figure 3. J1 and J2 are widely available cable TV female connectors. C1 and C2 capacitors placed between them should be about 0.01 µF each. The assembly does not require a printed circuit board. You might place it in a tiny box or just solder everything together, wrap it with electrical tape, and put it somewhere out of the way. Remember that the capacitors’ working voltage must be at least double the power distribution voltage. That is 250 V in North America and more than 500 V elsewhere in the world.

FIGURE 4: Ground isolator for three-prong powered appliances

FIGURE 4: Ground isolator for three-prong powered appliances

Figure 4 shows how to break ground for appliances, such as a PC, with three-prong plugs. You can build this circuit into a computer or another appliance, but I find it better to build it as an independent break-out box. The diodes provide open loop for signals up to about 1.3 VPP. A hum is usually of a substantially lower amplitude. C1, 0.01 µF, provides bypass for high-frequency EMI to ground. The loop would be closed for voltages higher than 1.3 VPP, such as the ones due to isolation fault of the hot wire to the chassis. For 120 VAC distribution, D1, D2, and C1 should be rated for 250 V at a minimum. In a circuit branch with a 15-A breaker or fuse, the diodes need to be rated for a minimum of 20 A so that the breaker opens up before the diodes blow. If the appliance takes only a fraction of the rated fuse current, say 2 A, you could use 5-A diodes and include an optional fuse rated for 2 A. For countries with 230-VAC power, the components must be rated accordingly.

You can also break the ground loop by using a power isolation transformer between the power line and the PC, or quality signal transformers on the signal lines. The downside of this is that good isolation and signal transformers are costly and not widely available. Equipment powered from wall warts—and especially those with optically coupled inputs and outputs, common today—is inherently ground loop impervious.

TRIAL & ERROR

This article describes an approach to eliminating ground loops in analog AV systems. While you need to understand how ground loops occur, finding them and eliminating their effects may turn out to be a matter of frustrating trial and error.

George Novacek is a professional engineer with a degree in Cybernetics and Closed-Loop Control. Now retired, he was most recently president of a multinational manufacturer for embedded control systems for aerospace applications. George wrote 26 feature articles for Circuit Cellar between 1999 and 2004. Contact him at gnovacek@nexicom.net with “Circuit Cellar” in the subject line.

This article appears in Circuit Cellar 301 August 2015.

TRACE32 Supports Spansion HyperFlash Memory

Lauterbach recently announced its support for the Spansion HyperFlash Memory with the TRACE32 tools. HyperBus Interface was introduced by Spansion in 2014 as an improvement on today’s low pin count memory interfaces and has been broadly implemented by the system-on-chip (SoC) manufactures.trace32_Lauterbach

HyperFlash Memory is based on the HyperBus interface and provides the important characteristics such as low latency, high read throughput, and space efficiency. TRACE32 tools support the HyperFlash memory with the intuitive, fast, and flexible Flash Programming feature that also provides you with control of reading, displaying, and erasing the content of the flash memory. The content is displayed in a standard hex dump, which allows the contents to be checked quickly. The tool supports the pairing of HyperFlash memory with the HyperBus interface and also with the ordinary Quad SPI controller.

Source: Lauterbach

Universal Trigger and Decoder Option for R&S Digital Oscilloscopes

Rohde & Schwarz has expanded its range of trigger and decoder options for the R&S RTO and R&S RTE digital oscilloscopes. With the R&S RTx-K50, the oscilloscopes help you debug serial protocols that employ Manchester or NRZ coding. The option can be used with a variety of standardized buses (e.g., PROFIBUS, DALI, or MVB) as well as with proprietary serial protocols. Developers of products that use these types of interfaces can easily find implementation errors and so test and release their designs more quickly.RTO-Rohde

The option, which covers data rates of up to 5 Gbps, supports up to 50 different telegram formats, while the format of the serial bus can be configured flexibly. You can define your own preamble, frame ID, data, CRC and other telegram fields. Protocol decoding also takes Manchester code violations into account.

High acquisition rates and minimal blind times are provided by the hardware-based trigger implementation on the oscilloscopes. You can trigger on telegram and data content with the R&S RTx-K50 option. The decoded protocol content is displayed in an easy-to-read, color-coded format. Time correlation with the analog signal makes it easy to identify faults caused by signal integrity problems. A tabular list of the protocol contents is also provided. The standard mask test with up to 600,000 tests per second makes it possible to check the signal quality faster with an eye diagram than with any other solution. In addition, both oscilloscope series from Rohde & Schwarz support the option of decoding up to four different serial protocols in parallel.

Source: Rohde & Schwarz

RED EXPERT Online Design Tool for Precise AC Loss Calculation

Würth Elektronik recently published RED EXPERT,  a new online tool you can use to simulate the power inductors. With just a few clicks, you can select the power inductors and calculate the complete AC losses.Wurth-RedExpert

RED EXPERT enables extremely precise loss calculation because it is not based on the known Steinmetz models with sinusoidal excitation. Instead, it is derived and validated from measurements of the power inductors in a switching controller setup.

The losses determined with RED EXPERT are based on current and voltage waveforms typical in applications. Besides the core and winding losses, they also include the losses arising from the specific geometries of the inductance, such as the air gap.

Particular highlights of the RED EXPERT AC loss model are the range of duty cycles supported from 10% to 90% and the switching frequency range of 50 kHz to 5 MHz. This gives the RED EXPERT AC loss model a previously unattained precision.

RED EXPERT is freely available in German, English, Spanish, Japanese, Russian, and Chinese at www.we-online.com/redexpert.

Source: Würth Elektronik

Two-Pin, Self-Powered Serial EEPROM for the IoT

Atmel recently announced a two-pin, single-wire EEPROM intended for the Internet of Things (IoT), wearables, and more. The self-powered devices don’t require a power source or VCC pin, with a parasitic power scheme over the data pin. They provide ultra-low power standby of 700 nA, 200 µA for write current, and 80 µA for read current at 25°C.

The AT21CS01/11 devices eliminate the need for external capacitors and rectifiers with its parasitic power scheme over a single data pin. Plus, their ultra-high write endurance capability to allow more than 1 million cycles for each memory location to meet the requirements for today’s high-write endurance applications.

The AT21CS01/11 products include a simple product identification with a plug-and-play, 64-bit unique serial number in every device. Furthermore, they deliver industry-leading electrostatic discharge (ESD) rating (IEC 61000-4-2 Level 4 ESD Compliant), so a variety of applications (e.g., cables and consumables) can tolerate exposure to the outside environment or direct human contact while still delivering high performance.

The new devices follow the I2C protocol, which enables easy migration from existing EEPROM with less overhead and the capability to connect up to eight devices on the same bus. The AT21CS01 devices offer a security register with a 64-bit factory programmed serial number and an extra 16 bytes of user-programmable and permanently lockable storag.

The AT21CS01 is intended for low-voltage applications operating at 1.7 to 3.6 V. For applications that require higher voltage ranges (e.g., Li-Ion/polymer batteries), the AT21CS11 supports a 2.7 to 4.5 V operating range.

The AT21CS01 devices are available in production quantities in three-lead SOT23, eight-lead SOIC, and four-ball WLCSP. Pricing starts at $0.32 in 5,000-piece quantities. The AT21CS11 will be available in Q4 2015.

Source: Atmel