5 W AC-DC Converter Boasts Wide Input Voltage Range

Aimtec has announced a 5 W AC/DC converter, the AMEL5-277NZ, that has been designed to offer greater economies of scale due to greater production automation, leading to improved reliability and performance. Offering a wide industrial input voltage range of 85- 305 VAC and an output voltage range from 3.3-24 V, this series offers many benefits for embedded systems designs.

This new series offers wide operating temperatures, from -40℃ to 70℃ and isolation of 4, 000 VAC for improved reliability and system safety. Furthermore, a high MTBF of 300,000 hours, output short circuit protection (OSCP), output over-current protection (OCP) and an output over-voltage protection (OVP) come standard with the series. The AMEL5-277NZ is well suited for street lighting controls, grid power, instrumentation, industrial controls, telecom and industry 4.0.

Aimtec | www.aimtec.com

IC Solutions Rev Up for Next Gen Auto Designs

MCUs, Analog ICs and More

Automotive electronics are evolving to facilitate the shift from driver assisted vehicle controls to full autonomous driving—but that’s only part of all that’s happening. To meet a variety of design challenges, MCU and analog IC vendors are developing innovative solutions for automotive systems.

By Jeff Child, Editor-in-Chief

There’s perhaps no more vivid example of the impact of embedded electronics than the continuing advances in automotive technologies. Today, those advances are set within an era of great innovation in the industry as car makers evolve their driver assistance technologies in parallel with their autonomous vehicle solutions, while at the same time improving the performance of full electric and hybrid electric vehicles. On top of all that, car infotainment systems are moving to an entirely new level.

To meet these system design changings automotive IC makers, continue to roll out chip, development system and software solutions aimed at next-gen automotive designs. Over the past 12 months, chip vendors, primarily microcontroller (MCU) and analog IC vendors, have announced a variety of powerful System-on-Chip (SoC), MCU and analog ICs solving all kinds of problems. Leveraging their long histories of serving the automotive market, the leading MCU vendors have taken the lead facilitating driverless car systems with not just chips, but also sophisticated development platform solutions for advanced driving assistance systems (ADAS), battery management and other automotive subsystems.

Flash for Virtualization

Some of the advances in automotive electronics over the past 12 months have revolved around embedded flash solutions aimed directly at automotive system designs. In an example along those lines, in February, Renesas Electronics announced what it claims as the world’s first MCU with embedded flash that integrates a hardware-based virtualization-assisted function while maintaining the fast, real-time performance of the RH850 products.

Figure 1
The RH850/U2A MCU is equipped with up to four 400 MHz CPU cores in a dual core lock-step structure. Each CPU core integrates a hardware-based virtualization-assisted function.

This hardware-based virtualization assist technology can support up to ASIL D level of functional safety, providing greater levels of system integration. The RH850/U2A MCU (Figure 1) is the first member of Renesas’ cross-domain MCUs, a new generation of automotive-control devices, designed to address the growing need to integrate multiple applications into a single chip to realize a unified electronic control units (ECUs) for the evolving electrical-electronic architecture (E/E architecture).

Based on 28 nm process technology, the 32-bit RH850/U2A MCU builds on key functions from Renesas’ RH850/Px Series for chassis control and RH850/Fx Series for body control to deliver improved performance and implement a virtualization-assisted function to support operation in chassis/safety, body, domain control and low-end/mid-range gateway applications. The RH850/U2A MCU is equipped with up to four 400 MHz CPU cores in a dual core lock-step structure. Each CPU core integrates a hardware-based virtualization-assisted function, while maintaining the same fast real-time performance provided by the RH850. To support ASIL D, the MCU includes self-diagnostic SR-BIST (Standby-Resume BIST) functions with minimized current fluctuation rate.

The hardware-based virtualization-assisted function allows multiple software systems with varying ISO 26262 functional safety levels to operate independently without interference during high performance. It also reduces the virtualization overhead to maintain real-time execution. This enables users to integrate multiple ECU functions into a single ECU while maintaining safety, security and real-time operation requirements.
The RH850/U2A MCU is equipped with up to 16 MB of built-in flash ROM and 3.6 MB of SRAM, offering users the flexibility for future function expansion. The MCU includes security functions that support Evita Light up through Evita Full for enhanced protection against cyber-attacks, enabling the device to support safe and rapid Full No-Wait Over-the-Air (OTA) software updates as security requirements evolve.

Fail-Safe Storage

In other automotive flash technology news, in April Cypress Semiconductor announced that automotive supplier DENSO selected Cypress’ Semper fail-safe storage for its next-generation digital automotive cockpit applications with advanced graphics. Based on an embedded Arm Cortex-M0 processing core, the Semper family is purpose-built for automotive environments.

The Cypress Semper family offers high density serial NOR flash memory up to 4 Gb and leverages the company’s proprietary MirrorBit process technology. The family also features EnduraFlex architecture, which achieves greater reliability and endurance. Semper fail-safe storage devices were the first in the industry to achieve the ISO 26262 automotive functional safety standard and are ASIL-B compliant, says Cypress. According to Cypress, the Semper fail-safe storage products exceed automotive quality and functional safety requirements with ASIL-B compliance and are ready for use in ASIL-D systems. Cypress’ 512 Mb, 1 Gb and 2 Gb Semper devices are currently sampling.

Domain Controllers

For its part, STMicroelectronics (ST) also rolled out a new automotive-focused MCU offering back in February. Called the Stellar automotive MCU family, these devices support next-generation car architectures, which rely on broad “domain controllers” for areas such as the drivetrain, the chassis, and Advanced Driver Assistance Systems (ADAS). These domain controllers enable the transition toward software- and data-oriented architectures by providing data fusion from connected sensors while reducing harness complexity

Figure 2
The Stellar MCUs feature six Arm Cortex-R52 cores clocked at 400 MHz, 16 MB of Phase-Change Memory (PCM) and 8 MB of RAM, all in a BGA516 package.

Built on a 28 nm FD-SOI process, major applications for Stellar MCUs include smart control for hybrid powertrain, the broad electrification of car systems with on-board chargers, battery-management systems and DC-DC controllers, as well as smart gateways, ADAS and enhanced Vehicle Stability Controls. The MCUs feature six Arm Cortex-R52 cores clocked at 400 MHz, 16 MB of Phase-Change Memory (PCM) and 8 MB of RAM, all in a BGA516 package (Figure 2). Stellar-based control units are currently undergoing road tests with lead customers. …

Read the full article in the August 349 issue of Circuit Cellar
(Full article word count: 3207 words; Figure count: 8 Figures.)

Vendor list:

Cypress Semiconductor | www.cypress.com
Infineon Technologies | www.infineon.com
Maxim Integrated | www.maximintegrated.com
Microchip | www.microchip.com
Momenta | www.momenta.ai
NXP Semiconductor | www.nxp.com
Renesas Electronics America | www.renesas.com
STMicroelectronics | www.st.com
Texas Instruments | www.ti.com

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!

Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

Tiny Amplifiers Enable Small High Performance System Designs

Texas Instruments has introduced what it claims is the industry’s smallest current-sense amplifier in a leaded package and the smallest, most accurate comparators with an internal 1.2-V or 0.2-V reference. Offered in industry-leading package options, the INA185 current-sense amplifier, and open-drain TLV4021 and push-pull TLV4041 comparators enable engineers to design smaller, simpler and more integrated systems while maintaining high performance. In addition, pairing the amplifier with one of the comparators produces the smallest, highest performing overcurrent detection solution in the industry, says TI.

These new devices are optimized for a variety of personal electronics, enterprise, industrial and communications applications, including peripherals, docking stations and notebooks. With a small-outline transistor (SOT)-563 package measuring 1.6 mm by 1.6 mm (2.5 mm2), the amplifier is 40% smaller than the closest competitive leaded packages. Featuring a 55-µV input offset that enables higher precision measurements at low currents, the INA185 enables the use of lower-value shunt resistors to cut system power consumption. Additionally, its 350-kHz bandwidth and 2-V/µS slew rate enable phase-current reproduction to enhance motor efficiency and save system power.

The precisely matched resistive gain network in the amplifier enables a maximum gain error as low as 0.2%, which contributes to robust performance over temperature and process variations. The device’s typical response time of 2 µs enables fast fault detection to prevent system damage.

System designers can add functionality in the same form factor and enable high-performance design with the TLV4021 and TLV4041 comparators. Available in an ultra-small die-size ball-grid array (DSBGA) 0.73-mm-by-0.73-mm package, the comparators’ integrated voltage reference saves board space while supporting precise voltage monitoring, which optimizes system performance.

The comparators can monitor voltages as low as the 0.2-V internal reference, and feature a high threshold accuracy of 1% across a full temperature range from -40°C to +125°C. Low 2.5-µA quiescent current delivers extended battery life for smart, connected devices. Fast propagation delay as low as 450 ns reduces latency, enabling power-conscious systems to monitor signals and respond quickly to fault conditions.

When using both the INA185 and the TLV4021 or TLV4041, engineers can shrink their total footprint to enable smaller systems. In combination, these devices produce the smallest, highest-performing overcurrent detection solution–15% smaller and 50 times faster than competitive devices. Pairing the amplifier with one of the comparators to support overcurrent detection on rails as high as 26 V delivers more headroom to better manage current spikes.

Production quantities of the INA185 are now available through the TI store and authorized distributors in a SOT-563 package, measuring 1.6 mm by 1.6 mm. Pricing starts at US$0.65 in 1,000-unit quantities. Production quantities of the push-pull TLV4041 and preproduction samples of the open-drain TLV4021 comparators are now available through the TI store and authorized distributors in an ultra-small DSBGA package, measuring 0.73 mm by 0.73 mm. Pricing for each comparator starts at US$0.39 in 1,000-unit quantities.

Texas Instruments | www.ti.com

Bidirectional Current Sense Amplifier Features PWM Rejection

Maxim Integrated has introduced the MAX40056, a bidirectional current sense amplifier with patented pulse-width modulation (PWM) rejection. This high speed, wide-bandwidth amplifier extends Maxim’s family of precision, high-voltage current sense amplifiers into motor control applications.

Creating a motor control system requires precise current sensing and measurement of motor winding currents, says Maxim. A commonly used approach is to infer winding currents by performing ground or supply referenced measurements in the bridge circuit. Direct winding current measurement is a simpler and more accurate method, but the implementation is challenging due to the high common mode swing of the PWM signal. Adoption of this approach has been limited by poor PWM rejection and slow settling speed of existing solutions.

MAX40056 rejects PWM slew rates of greater than 500 V/µs and settles within 500 ns to provide 0.3 percent accurate, full-scale winding current measurement. The patented PWM rejection scheme achieves 4 times faster settling time than competitive offerings, allowing motor control designers to increase drive frequency or decrease minimum duty cycle without sacrificing measurement accuracy. Higher PWM frequency smooths out the current flow and reduces torque ripple, resulting in more efficient motor operation.

Accurate winding current measurement at low duty cycle helps reduce or virtually eliminate vibration when the motor is running at a slow speed. MAX40056 has a wide common mode voltage range of -0.1 V to +65 V and a protection range of -5 V to 70 V to ensure the inductive kickback does not damage the IC. With bi-directional sensing capability, it is well suited for DC motor control, base station, datacenter, battery stack and many other applications which require precise current measurements in noisy environments.

The MAX40056 is available at Maxim’s website for $1.19 (1000-up, FOB USA), also available from authorized distributors. The MAX40056EVKIT evaluation kit is available for $69.

Maxim Integrated | www.maximintegrated.com

8 GHz 12-bit ADC Boasts 10.5 GSPS Sampling Rate

Texas Instruments (TI) has introduced a new ultra-high-speed ADC with what it claims is the industry’s widest bandwidth, fastest sampling rate and lowest power consumption. The ADC12DJ5200RF helps engineers achieve high measurement accuracy for 5G testing applications and oscilloscopes, and direct X-band sampling for radar applications, says TI. The company is demonstrating the ADC12DJ5200RF in booth No. 1272 at the International Microwave Symposium (IMS) in Boston this week (June 4-6).
The ADC12DJ5200RF’s 8 GHz bandwidth enables engineers to achieve as much as 20 percent higher analog input bandwidth than competing devices, which gives engineers the ability to directly digitize very high frequencies without the power consumption, cost and size of additional down-conversion. In dual-channel mode, the ADC12DJ5200RF samples at 5.2 GSPS and captures instantaneous bandwidth (IBW) as high as 2.6 GHz at 12-bit resolution. In single-channel mode, the new ultra-high-speed ADC samples at 10.4 GSPS and captures IBW up to 5.2 GHz.

As the first standalone GSPS ADC to support the JESD204C standard interface, according to TI, the ADC12DJ5200RF helps minimize the number of serializer/deserializer lanes needed to output data to field-programmable gate arrays (FPGAs), enabling designers to achieve higher data rates.

TI says the ADC12DJ5200RF has the highest available dynamic performance across power-supply variations, even at minimum specifications, which improves signal intelligence by providing ultra-high receiver sensitivity to detect even the smallest and weakest signals. In addition, the device includes internal dither which improves spurious-free performance.

High measurement accuracy means the device greatly minimizes system errors with offset error as low as ±300 µV and zero temperature drift. Engineers designing test and measurement equipment can achieve high measurement repeatability by taking advantage of the extremely low code error rate (CER) of the ADC12DJ5200RF, which is more than 100 times better than competing devices.

At 10 mm by 10 mm – 30 percent smaller than discrete solutions – the ADC12DJ5200RF helps engineers save board space. This ADC also requires a reduced number of lanes, which further allows for a smaller printed circuit board design. Engineers can minimize heat dissipation and simplify overall thermal management in their designs with the ADC12DJ5200RF 4-W power consumption, 20 percent lower than competitive ADCs.

The ADC12DJ5200RF is pin-compatible with the following other TI GSPS ADCs to provide an easy upgrade path from 2.7 GSPS to 10.4 GSPS, and minimizes the time and cost of redesign: ADC12DJ3200, ADC12DJ2700 and ADC08DJ3200. The ADC12DJ5200RF dual- and single-channel ultra-high-speed ADC is available for sampling through the TI store. The device is in a 144-ball, 10-by-10-mm flip-chip ball grid array (FCBGA) package.

Texas Instruments | www.ti.com

GPS Guides Robotic Car

Arduino UNO in Action

In this project article, Raul builds a robotic car that navigates to a series of GPS waypoints. Using the Arduino UNO for a controller, the design is aimed at robotics beginners that want to step things up a notch. In the article, Raul discusses the math, programming and electronics hardware choices that went into this project design.

By Raul Alvarez-Torrico

In this article I lay out a basic differential drive robotic car for waypoint autonomous navigation using the Global Positioning System (GPS). The robotic car receives a list of GPS coordinates, and navigates to waypoints in their given order. To understand how it works, I will discuss concepts about GPS, a simple approach to implement autonomous navigation using GPS, the hardware required for the task, how to calculate navigation vectors using the “Haversine Formula” and the “Forward Azimuth Formula” and a simple implementation of a moving average filter for filtering the GPS coordinate readings. I also discuss a simple approach to navigation control by minimizing the robotic car’s distance and heading error with respect to the goal.

This project is aimed at beginners with basic robotic car experience—that is, line followers, ultrasonic obstacle avoiders and others who now want to try something a little more complex—or anyone who is interested in the subject.

Figure 1 shows the main components of the system. The GPS receiver helps to calculate the distance from the robotic car to the goal. With the aid of a digital compass, the GPS also helps to determine in which direction the goal is located. Those two parameters—distance and direction—give us the navigation vector required to control the robotic car toward the goal. I used a four-wheel differential drive configuration for the car, which behaves almost the same as a two-wheel differential drive. The code provided with the project should work well with both configurations.

Figure 1
GPS Robotic Car block diagram

To calculate the distance to the goal, I used the Haversine Formula, which gives great-circle distances between two points on a sphere from their longitudes and latitudes. The Forward Azimuth Formula was used to calculate the direction or heading. This formula is for the initial bearing which, if followed in a straight line along a great-circle arc, will take you from the start point to the end point. Both parameters can be calculated using the following known data: The goal’s GPS coordinate, the robotic car’s coordinate obtained from the GPS receiver and the car’s heading with respect to North obtained from the digital compass.

The robotic car constantly recalculates the navigation vector and uses the obtained distance and heading to control the motors to approach the goal. I also put a buzzer in the robotic car to give audible feedback when the robotic car reaches the waypoints.


As shown in Figure 1, I used an Arduino UNO board as the main controller. I chose Arduino because it’s incredibly intuitive for beginners, and it has an enormous constellation of libraries. The libraries make it easy to pull off reasonably advanced projects, without excessive details about the hardware and software drivers for sensors and actuators.

The GPS receiver I chose for the task is the HiLetgo GY-GPS6MV2 module, based on the U-blox NEO-6M chip. The digital compass is the GY-271 module, based on the Honeywell HMC5883L chip. Both are low-cost and ubiquitous with readily available Arduino libraries. The U-blox NEO-6M has a UART serial communication interface, and the HMC5883L works with the I2C serial protocol. To avoid interference, the compass should be placed at least 15 cm above the rest of the electronics.

The DC motors are driven using the very popular L298N module, based on the STMicroelectronics L298N dual, full-bridge driver. It can drive two DC motors with a max current of 2 A per channel. It can also drive two DC motors in each channel if the max current specification is not surpassed—which is what I’m doing with the four-wheel drive chassis I used for my prototype. The chassis has a 30 cm × 20 cm aluminum platform, four generic 12 V DC 85 rpm motors and wheels that are 13 cm in diameter. But almost any generic two-wheel or four-wheel drive chassis can be used.

Figure 2
Circuit diagram for the Robotic Car project

For supplying power to the robotic car, I used an 11.1 V, 2,200 mA-hour (LiPo) Lithium-Polymer battery with a discharge rate of 25C. For my type of chassis, a battery half that size should also work fine. Figure 2 shows the circuit diagram for this project, and Figure 3 shows the finished car.

Figure 3
Completed GPS Robotic Car


The Global Positioning System (GPS) is a global navigation satellite system owned by the United States government. It provides geolocation and time information to any GPS receiver on the surface of the Earth, whenever it has unobstructed line of sight to at least four GPS satellites—the more the better [1]. GPS receivers typically can provide latitude and longitude coordinates with an accuracy of about 2.5 m to 5 m under ideal conditions, such as good sky visibility and lots of visible satellites. My robotic car is programmed with one or more waypoints given by latitude and longitude coordinates, and the car’s GPS receiver gives its actual position in the same type of coordinates.  …

Read the full article in the June 347 issue of Circuit Cellar
(Full article word count: 3773 words; Figure count: 8 Figures.)

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!

Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

Bidirectional Buck-Boost Controller Targets Autonomous Vehicles

Analog Devices has announced the Power by Linear LT8708/-1, a 98% efficient bidirectional buck-boost switching regulator controller that operates between two batteries that have the same voltage. This makes them well-suited for redundancy in self-driving cars. The LT8708/-1 operates from an input voltage that can be above, below or equal to the output voltage, making it well suited for two each 12 V, 24 V or 48 V batteries commonly found in electric and hybrid vehicles. It operates between two batteries and prevents system shutdown should one of the batteries fail. The LT8708/-1 can also be used in 48V/12V and 48V/24V dual battery systems.

The LT8708/-1 operates with a single inductor over a 2.8 V to 80 V input voltage range and can produce an output voltage from 1.3 V to 80 V, delivering up to several kilowatts of power depending on the choice of external components and number of phases. It simplifies bidirectional power conversion in battery/capacitor backup systems that need regulation of VOUT, VIN, and/or IOUT, IIN, both in the forward or reverse direction. This device’s six independent forms of regulation allow it to be used in numerous applications.

The LT8708-1 is used in parallel with the LT8708 to add power and phases. The LT8708-1 always operates as a slave to the master LT8708, can be clocked out-of-phase and has the capability to deliver as much power as the master. One or more slaves can be connected to a single master, proportionally increasing power and current capability of the system.

Another application is for an input voltage to power a load, where this same input voltage is used to power a LT8708/-1 circuit that charges a battery or bank of supercapacitors. When the input voltage goes away, the load maintains power without disruption from the battery or supercaps by way of the LT8708’s bidirectional capability.

Forward and reverse current can be monitored and limited for the input and output sides of the converter. All four current limits (forward input, reverse input, forward output and reverse output) can be set independently using four resistors. In combination with the DIR (direction) pin, the chip can be configured to process power from VIN to VOUT or from VOUT to VIN ideal for automotive, solar, telecom and battery-powered systems.

The LT8708 is available in a 5 mm × 8 mm QFN-40 package. Three temperature grades are available, with operation from –40 to 125°C for the extended and industrial grades and a high temp automotive range of –40°C to 150°C.

Pricing for the LT8708/-1 starts at $6.60 (1,000s).

Analog Devices | www.analog.com

LDO Regulators Target LoRa-Based IoT Systems

Semtech has added a new product to its nanoSmart platform of low power, Low Dropout (LDO) regulators that targets applications for IoT sensors including Semtech’s LoRa devices and wireless radio frequency technology (LoRa Technology).

A consistent voltage output with low noise (100μVRMS) is necessary for low-power radio devices, such as LoRa-based sensors, to function without noise interference with radio information transmission. The new nanoSmart SC573 device’s low quiescent current (50μA) enables energy savings in everyday products by extending operating life for battery-powered IoT sensors up to 10 years. The IC is ideal for developers designing solutions for industrial and consumer applications including smart metering and smart building.

Semtech’s nanoSmart ultra-low power technology enables energy savings in everyday products. The nanoSmart LDO products support multiple energy accumulation technologies including thermal, RF and indoor and outdoor solar. The platform implements advanced system power management and has a real-time clock making it ideal for remote sensing and control applications.


  • Shutdown current — 100 nA
  • Output noise — 100 μVRMS /V
  • Quiescent supply current — 50 μA
  • Input voltage range — 2.3 V to 5V
  • Single 300 mA (maximum) output
  • Internal 100 Ω output discharge
  • Dropout at 300 mA load — 180 mV

The new nanoSmart LDO is currently available in 2 voltages (3.3V and 1.8V) and is priced at $0.130 in volumes of 10,000 units.

Semtech | www.semtech.com

Power Alternatives for Commercial Drones

330 Power Drones for Web

Solution Options Expand

The amount of power a commercial drone can draw on has a direct impact on how long it can stay flying as well as on what tasks it can perform. But each kind of power source has its tradeoff.

By Jeff Child, Editor-in-Chief

Because extending flight times is a major priority for drone applications, drone system designers are constantly on the lookout for ways to improve the power performance of their products. For smaller, consumer “recreational” style drones, batteries are the obvious power source. But when you get into larger commercial drone designs, there’s a growing set of alternatives. Tethered drone power solutions, solar power technology, fuel cells and advanced battery chemistries are all power alternatives that are on the table for today’s commercial drones.

According to market research firm Drone Industry Insights, the majority of today’s commercial drones use batteries as a power source. As Lithium-polymer (LiPo) and Lithium-ion (Li-ion) batteries have become smaller with lower costs, they’ve been widely adopted for drone use. The advancements in LiPo and Li-ion battery technologies have been driven mainly by the mobile phone industry, according to Drone Industry Insights.

Batteries Still Leading

The market research firm points to infrastructure as the main advantage of batteries. They can be charged anywhere. While Li-Po and Li-Ion are the most common battery technologies for drones, other chemistries are emerging. Lithium Thionyl Chloride batteries (Li-SOCl2) promises a 2x higher energy density per kg compared to LiPo batteries. And Lithium-Air-batteries (Li-air) promise to be almost 7x higher. However, those options aren’t widely available and are expensive. Meanwhile, Lithium-Sulfur-batteries (Li-S) is a possible successor to Li-ion thanks to their higher energy density and the lower costs of using sulfur, according to Drone Industry Insights.

Photo 1 The Graphene Drone FPV Race series LiPo batteries provide lower internal resistance and less voltage sag under load than standard LiPo batteries. As a result, the battery packs stay cooler under extreme conditions

Photo 1
The Graphene Drone FPV Race series LiPo batteries provide lower internal resistance and less voltage sag under load than standard LiPo batteries. As a result, the battery packs stay cooler under extreme conditions

Meanwhile battery vendors continue to roll out new battery products to serve the growing consumer drone market. As an example, in June 2017 battery manufacturer Venom released its new Graphene Drone FPV Race series LiPo batteries. The batteries were engineered for the extreme demands of today’s first person view (FPV) drone racing pilots (Photo 1). The new batteries provide lower internal resistance and less voltage sag under load than standard LiPo batteries. As a result, the battery packs stay cooler under extreme conditions. The Graphene FPV Race series Li-ion batteries are 5C fast charge capable, allowing you to charge up to five times faster. All of the company’s Drone FPV Race packs include its patented UNI 2.0 plug system (Patent no. 8,491,341). The system uses a true Amass XT60 connector that attaches to the included Deans and EC3 adapter.

Chip vendors from the analog IC and microcontroller markets offer resources to help embedded system designers with their drone power systems. Texas Instruments (TI), for example, offers two circuit-based subsystem reference designs that help manufacturers add flight time and extend battery life to quadcopters and other non-military consumer and industrial drones.  …

Read the full article in the January 330 issue of Circuit Cellar

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!
Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

Negative Feedback in Electronics

Lead Image Novacek

A Look at the Opposite Side

Besides closed-loop control systems, negative feedback is found in many electronic circuits—especially in amplifiers. And just like positive feedback, negative feedback can significantly change or modify a circuit’s performance.

By George Novacek

Following last month’s discussion of positive feedback, let’s now take a look at its opposite: the negative feedback. Besides closed-loop control systems, it is found in many electronic circuits, especially in amplifiers. As we have already seen, feedback significantly changes or modifies a circuit’s performance. The end of the 19th century and the beginning of the 20th century was the era of introduction of the telephone. For long distance calls, amplifiers were needed along the telephone lines to make up for their transmission losses.

Vacuum tube amplifiers of the day suffered from many ailments: drift, high distortion and generally poor performance, making the long-distance voice communications nearly unintelligible. Harold Stephen Black, an AT&T engineer, was one of many working to solve this problem. Eventually—because he was familiar with the effects of negative feedback in mechanical systems—he tried to apply it to a vacuum tube amplifier. The result was astonishing and amplifiers with negative feedback have been with us ever since.

FIGURE 1 Transfer function of an operational amplifier with negative feedback

Transfer function of an operational amplifier with negative feedback

The op amp is the epitome of feedback application in electronic circuits. Because its comprehension is valid for all electronic feedback circuits, let’s take a closer look at the op amp. To analyze the negative feedback mathematically, we’ll consider an amplifier as a combination of two functional blocks: The open loop gain (OLG) block with transfer function A(s) and the feedback block with transfer function β(s). With monolithic amplifiers, the feedback is usually applied externally. The overall transfer function follows the principle shown in Figure 1.. …

Read the full article in the November 328 issue of Circuit Cellar

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!
Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

Analog ICs Meet Industrial System Needs

Jeff Lead Image Analog Inustrial

Connectivity, Control and IIoT

Whether it’s connecting with analog sensors or driving actuators, analog ICs play many critical roles in industrial applications. Networked systems add new wrinkles to the industrial analog landscape.

By Jeff Child

While analog ICs are important in a variety of application areas, their place in the industrial market stands out. Industrial applications depend heavily on all kinds of interfacing between real-world analog signals and the digital realm of processing and control. Today’s factory environments are filled with motors to control, sensors to link with and measurements to automate. And as net-connected systems become the norm, analog chip vendors are making advances to serve the new requirements of the Industrial Internet-of-Things (IIoT) and Smart Factories.

It’s noteworthy, for example, that Analog Devices‘ third quarter fiscal year 2017 report this summer cited the “highly diverse and profitable industrial market” as the lead engine of its broad-based year-over-year growth. Taken together, these factors all make industrial applications a significant market for analog IC vendors, and those vendors are keeping pace by rolling out diverse solutions to meet those needs.

Figure 1

Figure 1 This diagram from Texas Instruments illustrates the diverse kinds of analog sub-systems that are common in industrial systems—an industrial drive/control system in this case.

While it’s impossible to generalize about industrial systems, Figure 1 illustrates the diverse kinds of analog sub-systems that are common in industrial systems—industrial drive/control in that case. All throughout 2017, manufacturers of analog ICs have released a rich variety of chips and development solutions to meet a wide range of industrial application needs.


Programmable Logic Controllers (PLCs) remain a staple in many industrial systems. As communications demands increase and power management gets more difficult, transceiver technologies have evolved to keep up. PLC and IO-Link gateway systems must dissipate large amounts of power depending. That amount of power is often tied to I/O configuration—IO-Link, digital I/O and/or analog I/O. As these PLCs evolve into new Industrial 4.0 smart factories, special attention must be considered to achieve smarter, faster, and lower power solutions. Exemplifying those trends, this summer Maxim Integrated announced the MAX14819, a dual-channel, IO-Link master transceiver.

The architecture of the MAX14819 dissipates 50% less heat compared to other IO-Link Master solutions and is fully compatible in all modes for IO-Link and SIO compliance. It provides robust L+ supply controllers with settable current limiting and reverse voltage/current protection to help ensure robust communications with the lowest power consumption. With just one microcontroller, the integrated framer/UART enables a scalable and cost-effective architecture while enabling very fast cycle times (up to
400 µs) and reducing latency. The MAX14819 is available in a 48-pin (7 mm x 7 mm) TQFN package and operates over a -40°C to +125°C temperature range.  …

Read the full article in the November 328 issue of Circuit Cellar

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!
Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.