High-Side Current/Power Sensor

Microchip Technology recently introduced the PAC1921, a high-side current sensor with both a digital output, as well as a configurable analog output that can present power, current or voltage over the single output pin. Simultaneously, all power related output values are also available over the 2-Wire digital bus, which is compatible with I2C. The PAC1921 is available in a 10-lead 3 × 3 mm VDFN package. It was designed with the 2-Wire bus to maximize data and diagnostic reporting, while having the analog output to minimize data latency. The analog output can also be adjusted for use with 3-, 2-, 1.5-, or 1-V microcontroller inputs.Microchip PAC1921 Eval

The PAC1921 is ideal for networking, power-distribution, power-supply, computing and industrial-automation applications that cannot allow for latency when performing high-speed power management. A 39-bit accumulation register and 128 times gain configuration make this device ideal for both heavy and light system-load power measurement, from 0 to 32 V. It has the ability to integrate more than two seconds of power-consumption data. Additionally, the PAC1921 has a READ/INT pin for host control of the measurement period; and this pin can be used to synchronize readings of multiple devices.

The PAC1921 is supported by Microchip’s $64.99 PAC1921 High-Side Power and Current Monitor Evaluation Board (ADM00592). The PAC1921 is available for sampling and volume production, in a 10-lead 3 × 3 mm VDFN package, starting at $1.18 each in 5,000-unit quantities.

Source: Microchip Technology

Precision Set & Readback PMBus-Compatible µModule Regulator

Linear Technology recently announced the LTM4675 dual 9-A or single 18-A, µModule (micromodule) step-down DC/DC regulator with PMBus serial digital interface. It comes in a 11.9 mm × 16 mm × 3.51 mm BGA package. The I²C-based interface enables you to manage a system’s power condition and consumption. Calibrated and guaranteed from –40°C to 125°C, output DC voltage accuracy is ±0.5% over line and load regulation, and load current readback accuracy is ±2.5% maximum.Linear 4675

The LTM4675—which features EEPROM, power MOSFETs, inductors and supporting components—dual analog control loops and precision mixed-signal circuitry. It is drop-in pin-compatible with the larger package (16 mm × 16 mm BGA) higher power dual 13A LTM4676A, eliminating layout changes so that system designers can easily switch between the devices during the prototype phase. This eliminates redesign of power circuits if power requirements change during board prototyping. The LTM4675 has applications in optical transport systems, datacom and telecom switches and routers, industrial test equipment, robotics, RAID and enterprise systems where energy costs, cooling and maintenance are critical and must be continuously and precisely measured.

The LTM4675 operates from a 4.5-to-17-V input supply and steps down VIN to two outputs ranging from 0.5 to 5.5 V. Two channels can current share to provide up to 18 A (i.e., 9 A + 9 A as one output). Power-up turn-on time is 70 ms. To evaluate the performance of the LTM4675, the free LTpowerPlay GUI-based development system is available for download, and a USB-to-PMBus converter and demo kit are available. With ±0.5% maximum DC output error over temperature, ±2.5% current readback accuracy, integrated 16-bit delta-sigma ADC and EEPROM, the LTM4675 combines best-in-class analog switching regulator performance with precision mixed-signal data acquisition. At start-up, output voltages, switching frequency and channel phase angle assignments can be set by pin-strapping resistors.

The LTM4675 internal operating temperature range is from –40°C to 125°C.  It costs $24 in 1,000-piece units.

Source: Linear Technology

High-Speed, Conditioned Measurements with Channel-to-Channel Isolation

Measurement Computing Corp. recently announced the release of the SC-1608 Series of USB and Ethernet data acquisition devices. The series features analog signal conditioning that enables you to measure voltage, thermocouple, RTD, strain, frequency, and current. Isolated analog output and solid-state relays make it a good solution for systems requiring flexible conditioning and low cost per channel.MCC-SC-1608-Series

There are four devices in the SC-1608 Series with sample rates up to 500 ksps. Each device accommodates up to eight 8B isolated analog signal conditioning modules and eight solid state relay modules. Up to two isolated analog outputs are available on some models. Signal conditioning modules are sold separately.

Microsoft Windows software options for the SC-1608 include DAQami and TracerDAQ to display and log data, along with comprehensive support for C, C++, C#, Visual Basic, and Visual Basic .NET. Support is also included for DASYLab and NI LabVIEW. UL for Android provides programming support for Android devices. Open-source Linux drivers are also available.

The SC-1608 Series costs $999.

Source: Measurement Computing Corp.

Wireless Data Link

In 2001, while working on self-contained robot system called “Scout,” Tom Dahlin and Donald Krantz developed an interesting wireless data link. A tubular, wheeled robot, Scout’s wireless data link is divided into separate boards, one for radio control and another containing RF hardware.

Dahlin and Krantz write:

This article will describe the hardware and software design and implementation of a low-power, wireless RF data link. We will discuss a robotic application in which the RF link facilitates the command and control functions of a tele-operated miniature robot. The RF Monolithics (RFM) TR-3000 chip is the core of the transceiver design. We use a straightforward interface to a PIC controller, so you should be able to use or adapt much of this application for your needs…

Photo 1: The robot measures a little over 4″. Designed for tele-operated remote surveillance, it contains a video camera and transmitter. Scout can hop over obstacles by hoisting its tail spring (shown extended) and quickly releasing it to slap the ground and propel the robot into the air.

Photo 1: The robot measures a little over 4″. Designed for teleoperated remote surveillance, it contains a video camera and transmitter. Scout can hop over obstacles by hoisting its tail spring (shown extended) and quickly releasing it to slap the ground and propel the robot into the air.

The robot, called Scout, is packed in a 38-mm diameter tube with coaxial-mounted wheels at each end, approximately 110-mm long. The robot is shown in Photo 1. (For additional information, see the “Key Specifications for Scout Robot” sidebar.) Scout carries a miniature video camera and video transmitter, allowing you to tele-operate the robot by sending it steering commands while watching video images sent back from Scout. The video transmitter and data transceiver contained on the robot are separate devices, operating at 915 and 433MHz, respectively. Also contained on Scout are dual-axis magnetometers (for compass functions) and dual-axis accelerometers (for tilt/inclination measurement).

Figure 1: For the radio processor board, a PIC16F877 provides the horsepower to perform transceiver control, Manchester encoding, and packet formatting.

Figure 1: For the radio processor board, a PIC16F877 provides the horsepower to perform transceiver control, Manchester encoding, and packet formatting.

Scout’s hardware and software were designed to be modular. The wireless data link is physically partitioned onto two separate boards, one containing a PIC processor for radio control, message formatting, and data encoding (see Figure 1). The other board contains the RF hardware, consisting of the RFM TR3000 chip and supporting discrete components. By separating the two boards, we were able to keep the digital noise and trash away from the radio.

Read the full article.

USB-to-FPGA Communications: A Case Study of the ChipWhisperer-Lite

Sending data from a computer to an FPGA is often required. This might be FPGA configuration data, register settings, or streaming data. An easy solution is to use a USB-connected microcontroller instead of a dedicated interface chip, which allows you to offload certain tasks into the microcontroller.

In Circuit Cellar 299 (June 2015), Colin O’Flynn writes:

Often your FPGA-based project will require computer communication and some housekeeping tasks. A popular solution is the use of a dedicated USB interface chip, and a soft-core processor in the FPGA for housekeeping tasks.

For an open-source hardware project I recently launched, I decided to use an external USB microcontroller instead of a dedicated interface chip. I suspect you’ll find a lot of useful design tidbits you can use for yourself—and, because it’s open source, getting details of my designs doesn’t involve industrial espionage!

The design is called the ChipWhisperer-Lite (see Photo 1). This device is a training aid for learning about side-channel power analysis of cryptographic implementations. Side-channel power analysis uses measurements of small power variations during execution of the cryptographic algorithms to break the implementation of the algorithm.

Photo 1: This shows the ChipWhisperer-Lite, which contains a Xilinx Spartan 6 LX9 FPGA and Atmel SAM3U2C microcontroller. The remaining circuitry involves the power supplies, ADC, analog processing, and a development device which the user programs with some cryptographic algorithm they are analyzing.

Photo 1: This shows the ChipWhisperer-Lite, which contains a Xilinx Spartan 6 LX9 FPGA and Atmel SAM3U2C microcontroller. The remaining circuitry involves the power supplies, ADC, analog processing, and a development device which the user programs with some cryptographic algorithm they are analyzing.

In a previous article, “Build a SoC Over Lunch” (Circuit Cellar 289, 2014), I made the case for using a soft-core processing in an FPGA. In this article I’ll play the devil’s advocate by arguing that using an external microcontroller is a better choice. Of course the truth lies somewhere in between: in this example, the requirement of having a high-speed USB interface makes an external microcontroller more cost-effective, but this won’t always be the case.

This article assumes you require computer communication as part of your design. There are many options for this. The easiest from a hardware perspective is to use a USB-Serial converter, and many projects use such a system. The downside is a fairly slow interface, and the requirement of designing a serial protocol.

A more advanced option is to use a USB adapter with a parallel interface, such as the FTDI FT2232H. These can achieve very high-speed data rates—basically up to the limit of the USB 2.0 interface. The downside of these options is that it still requires some protocol implemented on your FPGA for many applications, and it has limited extra features (such as if you need housekeeping tasks).

The solution I came to is the use of a USB microcontroller. They are widely available from most vendors with USB 2.0 high-speed (full 480 Mbps data rate) interfaces, and allow you to perform not only the USB interface, but the various housekeeping tasks that your system will require. The USB microcontroller will also likely be around the same price (or possibly cheaper) than the equivalent specialized interface chip.

When selecting a microcontroller, I recommend finding one with an external memory bus interface. This external memory bus is normally designed to allow you to map devices such as SRAM or DRAM into the memory space of the microcontroller. In our case we’ll actually be mapping FPGA registers into the microcontroller memory space, which means we don’t need any protocol for communication with the FPGA.


Figure 1: This figure shows the basic connections used for memory-mapping the FPGA into the microcontroller memory space. Depending on your requirements, you can add some additional custom lines, such as a flag to indicate different FPGA register banks to use, as only a 9-bit address bus is used in this example.

I selected an Atmel SAM3U2C microcontroller, which has a USB 2.0 high-speed interface. This microcontroller is low-cost and available in TQFP package, which is convenient if you plan on hand assembling prototype boards. The connections between the FPGA and microcontroller are shown in Figure 1.

On the FPGA, it is easy to map this data bus into registers. This means that to configure some feature in the FPGA, you can just directly write into a register. Or if you are transferring data, you can read from or write to a block-RAM (BRAM) implemented in the FPGA.

Check out Colin’s ChipWhisperer-Lite KickStarter Video:

SimpleLink Simplifies IoT Prototyping

Texas Instruments recently introduced the next-generation SimpleLink SensorTag development kit, which enables the fast integration of sensor data with wireless cloud connectivity.TI Simplelink

Features of the new SensorTags include:

  • Flexible development with wireless connectivity options including Bluetooth low energy, 6LoWPAN and ZigBee based on the SimpleLink ultra-low power CC2650 wireless microcontroller
  • 10 integrated low-power sensors
  • New DevPack plug-in modules that extend the kits’ functionality and programmability
  • Out of the box capabilities with a free iOS or Android app
  • Connect to the cloud in minutes via TI’s IoT cloud ecosystem including IBM’s Bluemix IoT Foundation
  • Available TI Design reference designs, including 3-D print files of the SensorTag enclosures, that enable you to reuse the SensorTags for new designs

The SensorTag kits come with ready-to-use protocol stacks, a free Code Composer Studio IDE license, online training, and 24/7 online TI E2E community support. In addition, TI’s cloud-based software development tools provide instant access to examples, documentation, software and even an integrated development environment (IDE) all from the convenience of the web.

Expanding the standards supported by the SensorTag, there will be two different development kit versions:

  • The multi-standard SensorTag, based on the SimpleLink ultra-low power CC2650 wireless MCU, supports development for Bluetooth Smart, 6LoWPAN and ZigBee. This SensorTag has a unique feature that enables developers to change between different 2.4-GHz technologies by simply loading new software images directly from the SensorTag app over-the-air. When the SensorTag is used as a ZigBee and 6LoWPAN device, it connects to the cloud via a BeagleBone Black gateway. For Bluetooth Smart development, it connects via a smartphone.
  • The Wi-Fi SensorTag will allow users to demo the SimpleLink CC3200 wireless MCU. Further details and availability information will be coming soon. Start developing today with the CC3200 solution with these development tools.
  • Both SensorTags come with 10 integrated low-power sensors including the TI OPT3001 precision ambient light sensor, TI HDC1000 integrated humidity and temperature sensor and TI TMP007 contactless IR thermopile sensor. Additional sensors include a nine-axis motion sensor (gyroscope, compass and accelerometer), altimeter/ pressure sensor, digital microphone, and magnet sensor.

New to the next-generation CC2650 SensorTag is the ability for developers to customize their kit to fit their design with new DevPack plug-in modules. DevPacks available today include:

  • The $15 Debug DevPack is based on the TM4C1294 microcontroller (MCU) to add debug capabilities to the SensorTag. Plug it into the DevPack expansion header and debug the SensorTag with Code Composer Studio IDE, TI Cloud Tools, or IAR embedded workbench for ARM.
  • The Display (watch) DevPack adds a 1.35 inch ultra-low power graphical display to the SensorTag. The Watch DevPack is designed for development of smartwatches, refrigerator displays and any other application that has a need for a remote display.
  • The LED Audio DevPack consists of four high power multi-color LEDs and a 4W audio amplifier powered by a micro-USB for home automation and smart lighting applications.
  • Create your own! If developers cannot find a specific DevPack to fit their needs, they can create their own by downloading the Build Your Own DevPack guide.

The new SimpleLink multi-standard CC2650 SensorTag (CC2650STK) is available now for $29 in the TI Store and authorized distributors. Related software for each connectivity standard is also available:

  • Bluetooth Smart software
  • 6LoWPAN software
  • ZigBee software

The SimpleLink SensorTag DevPacks are also available on the TI Store and through TI authorized distributors. The Debug DevPack (CC-DEVPACK-DEBUG) costs $15. The Display DevPack (DEVPACK-WATCH) costs $19. The LED Audio DevPack (DEVPACK-LED-AUDIO) is $19. Pricing and availability for the SimpleLink Wi-Fi CC3200 SensorTag will be coming later in 2015.

IAR Systems Celebrates 10,000 Supported Devices

IAR Systems is proud to announce that its complete C/C++ development toolchain IAR Embedded Workbench now supports more than 10,000 devices, from all major microprocessor vendors. This unparalleled wide support puts IAR Embedded Workbench in a class of its own, enabling users to work with the same user-friendly development tools for virtually any device on the market.IARSystems1000

In order to provide support for the largest number of 8-, 16- and 32-bit devices, IAR Systems has established strategic partnerships with leading microprocessor vendors such as Renesas, Atmel, STMicroelectronics, Freescale and Texas Instruments. The strong relationships and longstanding knowledge sharing with partners enables IAR Systems to deliver the market’s most comprehensive processor support by a wide margin. This has made it possible for some of the world’s largest corporations and thousands of small and mid-sized companies to standardize their development on IAR Systems’ software, gaining unique flexibility and freedom from having to consider the choice of software in their selection of microprocessor. The fact that IAR Systems’ customers are able to maintain their development environment when changing processor platform and reuse most of their code saves them both time and money.

“10,000 supported devices is a milestone for us and we are really proud to provide our customers with the unique flexibility that this record confirms,” comments Mats Ullström, Chief Operating Officer, IAR Systems. “It is a fact that no other embedded toolchain comes close to offering such a broad device support, and in addition, we provide leading code performance and excellent code quality. Developers can build what they want in the platform of their choice and always feel confident that we support the device.”

IAR Embedded Workbench is a powerful development toolchain that incorporates a compiler, an assembler, a linker and a debugger into one completely integrated development environment. Find all supported devices at www.iar.com/device-search.

Compact 20-A Power Module

Exar Corp. recently announced the XR79120, a 20-A single output, synchronous step-down power module in a compact, 12 mm x 14 mm x 4 mm footprint. Even though it’s small, the XR79120 offers more than 93% peak efficiency and leverages Exar’s patented advanced constant on-time (COT) control architecture across a 4.5-to-22-V input voltage range.EX042_XR79120 The easy-to-use XR79120 provides a fully integrated power converter integrating MOSFETs, inductors, and internal input and output capacitors. QFN-based package technology provides noteworthy thermal performance, eases electrical debugging, and improves manufacturability with higher assembly yield and the ability to visually inspect solder joints. At 50°C with no airflow, no thermal de-ratings are required for output voltages of 1.8 V and below.

The XR79120 will be available in a RoHS compliant, green/halogen free, space-saving 74-pin 12 mm × 14 mm × 4 mm QFN package. The XR79120 costs $13.95 in 1,000-piece quantities.

The XR79120’s features include:

•       Fully integrated power supply
•       12 mm × 14 mm × 4 mm QFN package
•       > 93% peak efficiency
•       4.5 to 22 V VIN operating range
•       Patented emulated current mode COT control
•       Exceptional line/load regulation

Source: Exar Corp.

GuruCE and Lauterbach Establish Official Partnership

Lauterbach and GuruCE—which manufactures high-quality Microsoft Windows Embedded Compact BSPs—recently announced an official partnership. The experts at GuruCE and Lauterbach already have a long working relationship that is now brought to an even higher level of cooperation.Web

Lauterbach’s debugging expertise combined with GuruCE’s Windows Embedded expertise has been critical in creating a highly reliable and extremely well performing iMX6 BSP for Windows Embedded Compact 7 and 2013. GuruCE now ships easy-to-use Lauterbach JTAG scripts with its iMX6 BSP so customers can, if needed, dive deep with the help of the best JTAG solutions for Windows Embedded Compact by Lauterbach.

Source: Lauterbach

What Is Correlation?

Interested in learning about correlation and how to implement it in a digital signal processing system? In Circuit Cellar 299, Robert Lacoste addresses the subject without going overboard with complicated mathematics. He explains how a simple correlation calculation can drastically improve a system’s performance.

Imagine a situation in which you have a noisy signal that includes replications of a given pattern. Each replication is more or less accurate, has a varying amplitude, and could be situated anywhere in the signal (see Figure 1). The pattern is known, even if it could have any shape. Also imagine that your boss or client asked you to find an algorithm that will locate each occurrence of the pattern in the signal and give an estimation of its amplitude. Not obvious, right? Well, it’s actually quite easy. This is a classic situation for which you can apply a simple mathematical operation: correlation.

Figure 1: This figure shows a given pattern (top) replicated two times in a noisy signal at different amplitudes (middle). The goal of the game is to identify the two replications (bottom).

Figure 1: This figure shows a given pattern (top) replicated two times in a noisy signal at different amplitudes (middle). The goal of the game is to identify the two replications (bottom).

Before I define correlation and explain how to implement it in a DSP system, let’s cover a few typical applications first. A radar system includes a transmitter and a receiver. The former sends out some pulses. The receiver must recognize the echoed pulses, which each corresponding to an obstacle. That’s exactly what a correlation is made for! Even if a radar is one of the best examples, there are thousands of other possible applications. Want to improve the performance of a sensor with information about the shape of the signal being detected? Use correlation. Need to identify a given vibration on an accelerometer-based system? Correlation is answer once again. The list is endless.


The good news about correlation is that the calculations are quite simple to explain and even simpler to implement in a software-based project or in an FPGA. Since I’m talking about digital systems, you can safely assume that the signal is digitized (by an analog-to-digital converter) and defined by N successive samples. Similarly, the pattern to be found is a set of M successive samples, which are also some numeric values. Let’s assume that the pattern is shorter than the input signal so that M < N. How should you proceed?

The correlation calculation works as follows. Start by positioning the pattern above the first M points of the signal. For each sample of the pattern, multiply the corresponding pattern and signal values and then sum all the results. You’ve got the first point of the correlation. Then shift the pattern by one sample on the right and do the same calculation again to find the second point of the correlation. Continue up to the end of the signal and you’ve got the correlation of the pattern and signal, which has N – M + 1 points in that case. Refer to Listing 1 if you prefer pseudocode to a description (assuming the index are numbered from 0 to N – 1).

Listing 1: This pseudo-code implements the correlation algorithmtion

Listing 1: This pseudo-code implements the correlation algorithm.

Very simple, right? The process is illustrated on Figure 2. How does this calculation answer to our problem? Very simply: The calculated correlation is higher when the signal and pattern matches.

Figure 2: A correlation works by progressively shifting the pattern (middle relatively to the signal (top). At each position, the two curves are multiplied term-by-term and summed, giving one point on the resulting correlation (bottom).

Figure 2: A correlation works by progressively shifting the pattern (middle relatively to the signal (top). At each position, the two curves are multiplied term-by-term and summed, giving one point on the resulting correlation (bottom).

So you have just to locate peaks on the calculated correlation. The position of the peaks shows where the pattern are located in the signal, and their amplitudes are directly proportional to the amplitude of the replica.—Robert Lacoste (Circuit Cellar 299, 2015)

This article appears in Circuit Cellar 299 (June 2015).

New USB3.0 Smart Hub Family

Microchip Technology recently announced  the USB5734/44, a USB3.0 Smart Hub family that enables host and device port swapping, I/O bridging, and other serial communication interfaces. The USB5734 and USB5744 devices feature an integrated microcontroller that creates new functionality for USB hubs while lowering overall BOM costs and reducing software complexity.MicrochipUSB5734

The new USB3.0 Smart hubs enable an upstream host controller to communicate to numerous types of external peripherals beyond the USB connection through direct bridging from USB to I2C, SPI, UART, and GPIO interfaces. This eliminates the need for an additional external microcontroller, while providing improved control from the USB host hardware.

Microchip’s FlexConnect technology enables the USB5734 Smart Hub to dynamically swap between a USB host and a USB device through hardware or software system commands giving the new USB host access to downstream resources. The FlexConnect technology can also switch common downstream resources between two different USB hosts. Incorporating FlexConnect into a system simplifies the overall software requirements of the primary host, as class drivers and application software stay local to the Device-turned-Host.

Available 56-pin, 7 x 7 mm package, the USB5744 is the industry’s smallest USB3.0 Hub for applications where board space is important. You can use the USB5734 and USB5744 USB3.0 controller hubs for a variety of applications (e.g., computing, embedded, medical, industrial, and networking markets).

The USB5734 and USB5744 are supported by Microchip’s $399 USB 3.0 Controller Hub Evaluation Board (EVB-USB5734) and $299 USB 3.0 Small Form Factor Controller Hub Evaluation Board (EVB-USB5744). The former includes mezzanine cards that can be used as preset application configurations for easy testing and development of a USB5734 system.

The USB5734 is available in 64-pin QFN (9 × 9 mm) packages starting at $4.20 each in 10,000-unit quantities. The USB5744 is available in 56-pin QFN (7 × 7 mm) packages starting at $3.75 each in 10,000-unit quantities.

Source: Microchip Technology

Innovative Magnetic Sensing Integrated IC

Texas Instruments recently unveiled the DRV421 magnetic sensing IC with a fully integrated fluxgate sensor and compensation coil driver. It includes all the required signal conditioning circuitry.DRV421_TI

Compared to traditional Hall effect sensors, the DRV421 provides high sensor accuracy and linearity, high dynamic range, and simpler system design. With it, you can easily design magnetic closed-loop current sensors for a variety of applications (e.g., motor control, renewable energy, battery chargers and power monitoring).

The $49 DRV421 evaluation module (DRV421EVM) makes it easy to evaluate the new current sensing IC’s features and performance. The DRV421 comes in a 4 mm- × 4 mm QFN package. Pre-production samples are available now. Production quantities will be available in Q3 2015 for 2.50 in 1,000-unit quantities.

Source: Texas Instruments

New Low-Cost MEMS Inertial Accelerometer

Silicon Designs recently announced the North American market introduction of the new Model 1525 Series integral inertial accelerometer family. Offering impressive low-noise performance, the nitrogen damped and hermetically sealed SDI Model 1525 Series is intended for tactical navigation, seismic, and other zero-to-medium frequency instrumentation applications that require high-repeatability, low noise, and maximum stability. SiliconDesigns 1525 MEMS Acc

Each miniature, hermetically sealed package combines a MEMS variable capacitive sense element and a custom integrated circuit that includes both a sense amplifier and 4.0 V differential output stage. Units are available in six unique full-scale ranges from 2 g to 100 g with reliable performance over a standard operating temperature range of –40°C to 85°C. Each device has a serial number for traceability. Each unit comes with a calibration test sheet showing measured bias, scale factor, linearity, operating current, and frequency response.

Source: Silicon Designs

Next-Gen Premium Multichannel DAC Series

A new series of 2/4/6/8-channel D/A converters from Asahi Kasei Microdevices (AKM) is powering the next generation of high-quality consumer electronic devices, measurement equipment, and control systems. The AK4452/AK4454/AK4456/AK4458 premium 32-bit DAC devices have up to eight channels. The devices are based on AKM’s Velvet Sound architecture. Combining fine sound details with the low-distortion architecture and 32-bit resolution digital filter processing, the new technology is already finding applications in new AV receivers, network audio and USB DACs, USB headphones, audio interfaces, and much more.AKM-NewDACsWeb

The digital input in the new DAC series supports up to 768-kHz PCM and 11.2-MHz Direct Stream Digital (DSD), suitable for high-resolution audio source playback. With up to eight channels and a TDM interface allowing daisy chaining, the series also provides a simple solution to a wide range of applications.

According to AKM, its Velvet Sound core architecture was designed specifically to support the high-resolution audio market and achieves the lowest distortion in the industry with –107 dB in the D/A conversion and 115-dB S/N. Using Over Sampling Ratio Doubler (OSRD), the new chips reduce out of band noise and include Impulse Response Designed (IRD) filters integrated with 32-bit processing. Five different digital filters types are selectable according to the user audio and system preferences.

The new lineup is available in 32-pin QFN, 5 × 5 mm (AK4452/AK4454) and 48-pin QFN, 7 × 7 mm (AK4456/AK4458) packages.

Via audioXpress

June Electrical Engineering Challenge Live (Sponsor: NetBurner)

Ready to put your electrical engineering skills to the test? The June Electrical Engineering Challenge (sponsored by NetBurner) is now live.

This month, find the error in the schematic posted below (and on the Challenge webpage) for a chance to win a NetBurner MOD54415 LC Development Kit ($129 value) or a Circuit Cellar Digital Subscription (1 year).


Find the error in the code and submit your answer via the online Submission Form by the deadline: 2 PM EST on May 20, 2015. Two prize winners from the pool of respondents who submit the correct answer will be randomly selected.

Find the error in this schematic and submit your answer via the online Submission Form by the deadline: 2 PM EST on June 20, 2015. Two prize winners from the pool of respondents who submit the correct answer will be randomly selected.


Out of each month’s group of entrants who correctly find the error in the code or schematic, one person will be randomly selected to win a NetBurner IoT Cloud Kit and another person will receive a free 1-year digital subscription to Circuit Cellar.

  • NetBurner MOD54415 LC Development Kit: You can add Ethernet connectivity to an existing product or use it as your product’s core processor! The NetBurner Ethernet Core Module is a device containing everything needed for design engineers to add network control and to monitor a company’s communications assets. The module solves the problem of network-enabling devices with 10/100 Ethernet, including those requiring digital, analog, and serial control.NetburnerMod54415module
  • Circuit Cellar Digital Subscription (1 year): Each month, Circuit Cellar magazine reaches a diverse international readership of professional electrical engineers, EE/ECE academics, students, and electronics enthusiasts who work with embedded technologies on a regular basis.Circuit Cellar magazine covers a variety of essential topics, including embedded development, wireless communications, robotics, embedded programming, sensors & measurement, analog tech, and programmable logic.


Read the Rules, Terms & Conditions


NetBurner solves the problem of network enabling devices, including those requiring digital, analog and serial control. NetBurner provides complete hardware and software solutions that help you network enable your devices.netburneroffer

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