In my first post, I talked about the need for modular, flexible and smart design in analog output modules and explored methods for improving efficiency in a typical high-side voltage-to-current converter used to drive 4-20mA outputs. Figure 1 shows an implementation that involves a buck/boost converter in a simple feedback network to supply just the necessary power to the load. While…
This post is co-authored by Richard Barthel and Errol Leon.
In applications such as position sensors, data-acquisition systems and resistance temperature detectors (RTDs), it is important to design with high precision in mind. In many cases, designing with precision integrated circuits (ICs) reduces signal-chain complexity, lowers the external component count, and…
Medical ultrasound is a noninvasive method of imaging the body’s internal structures (like organs) by transmitting high-frequency waves and measuring the reflections that occur at various boundaries within, such as between bone and muscle. There are different types of ultrasound, such as B-mode, F-mode (also known as pulsed-waveform) and continuous waveform Doppler (CW Doppler).…
Industry 4.0 has revolutionized the manufacturing industry, changing how factories are designed and implemented. In factory automation and process-control applications, Industry 4.0’s impact comes down to two fundamental concepts: the proliferation of decentralized systems and smart deterministic systems. Decentralized systems inherently need to be modular and flexible. Efficient…
As battery-powered systems become more common, quickly identifying a failing battery so that it can be replaced is becoming increasingly important. From an individual battery powering a mobile phone to a bank of batteries used to store renewable energy, a faulty battery can lead to system downtime. At the heart of battery analyzers, which determine the health of a battery, is a…
In this post, I’ll show how to design a cost-optimized, discrete, wide-bandwidth instrumentation amplifier using the TLV3544. Instrumentation amplifiers are used for their high input impedance and ability to convert differential voltages to single-ended voltages. Fast current sensing, precision data acquisition, vibration analysis, microphone pre-amplification, ADC drivers and…
Electronics such as smartphones, tablets, notebooks and wearable products are becoming more multifunctional, smaller and slimmer. Achieving higher functionality in smaller form factors requires extremely tiny ICs. Many times, different package types help reduce size and solve various design challenges. Take operational amplifiers (op amps), for example; wafer chip-scale packages…
The digital multimeter (DMM) is a centerpiece in any electronics lab, but as the precision of electronics continues to increase, so does the need for DMMs that can quickly and accurately measure current, voltage, resistance and other parameters. Thus, there is a constant need to improve the data-acquisition system within a DMM, enabling higher accuracy measurements. At the heart…
It’s simple to design a multiplexer (or mux for short) into a signal chain, right? After all, the device simply funnels multiple signals into a data converter.
In reality, a mux can significantly impact the performance of a signal chain in a variety of ways. For example, the on-capacitance can cause crosstalk between channels. Signal- and temperature-dependent variations in the on-resistance can introduce signal…
In my last post, I talked about how to use a precision digital-to-analog converter (DAC) to margin a voltage regulator like a low-dropout regulator (LDO) or switch mode power supply (SMPS), providing the ability to either precisely tune the output or allow it to swing over a wide range of voltages.
In this post, I will expand upon that idea to build a closed-loop system that, alongside…
In my previous post, I discussed the proper way to layout a printed circuit board (PCB) for an operational amplifier (op amp) and provided a list of good layout practices to follow. In this post, I will discuss common mistakes when laying out a PCB for an instrumentation amplifier (INA) and then show an example of a proper layout for an INA.
INAs are used in applications that require the amplification of a differential…
When responding to questions posted on TI E2E™ Community forums, we frequently run simulations using TINA-TI™ software, a SPICE-based simulation program. Since we are always in the process of updating our simulation models, we sometimes run across SPICE models that are old, outdated or incorrect when modeling performance parameters.
One recent example involves…
This technical article was updated on July 23, 2020.
High-precision data-acquisition systems are designed to minimize errors from various system components, like those introduced by switching transients on the reference input of a data converter. In the case of a successive approximation register analog-to-digital converter (SAR ADC), circuitry inside the data converter as it connects and disconnects different capacitive…
Do you feel like your adjustable voltage regulator deserves some margin? I do, and I have some good news: all it takes is one DAC and one resistor!
The traditional feedback system for a linear regulator (LDO), shown in Figure 1, has a resistor divider network from the voltage output to the feedback pin and then to ground. Choosing these resistor values determines…
Many sensors produce low-level DC outputs that require a high input-impedance amplification stage to increase the signal amplitude. Sensors used in personal and portable electronics require operational amplifier (op amp) circuits that provide high input impedance and DC precision, while also being low power and cost-effective.
In this post, I’ll explain how to design…
Protecting expensive, critical or hard-to-repair equipment against overcurrent and power-supply fault conditions can be achieved with universally available operational amplifiers (op amps) and a few external components.
In this post, I will present one example of a versatile variable load-current detection/protection scheme that you can easily alter for a large range of load currents…
In portable electronics designs, typical battery-monitoring systems measure battery voltage and battery current to detect when the battery needs charging or replacement. In this post, I’ll demonstrate battery-voltage and current-monitoring circuitry for cost-optimized systems using operational amplifiers (op amps).
Op amps used in battery-monitoring circuitry must meet…
In my last blog post, I talked about sinc filters and their unique relationship with delta-sigma analog-to-digital converters (ADCs). I explained that sinc filters are great for applications with low bandwidth because of their quick settling time and low-pass characteristics.
But what if your application isn’t low bandwidth? What if you would like to measure sound or vibrations…
This post is co-authored by Rahul Prakash.
Pop quiz: What’s the most requested feature in modern-day industrial systems?
If you guessed accuracy, then you are correct. In the past, only the test and measurement market needed highly accurate signal-chain components, but now other industrial markets such as factory automation, optical networking and medical require high accuracy…
This post is co-authored by Raphael Puzio.
Photodiode-based light sensing is a common application of operational amplifiers (op amps) used in medical equipment, industrial automation, robotics, point-of-sale machines, drones, smoke detectors and building automation equipment. This blog demonstrates how to build a cost-sensitive, accurate photodiode circuit.
A photodiode sensor produces a current proportional to the light…
In my last post, I talked about the different types of digital filters commonly used in delta-sigma analog-to-digital converters (ADCs). In this post, let’s focus on the most common type of digital filter used in delta-sigma ADCs: the sinc filter.
So what is a sinc filter, exactly? And why is it used so often in delta-sigma ADCs? Well, like I mentioned in my last blog post,…
This technical article was updated on July 23, 2020.
When trying to reduce system power consumption, one method is to look for devices to optimize or remove. Another method is to evaluate the system as a whole and optimize for system functionality before evaluating at the component level. In this post, I’ll go over design techniques using low-power analog components…
Have you ever wondered how delta-sigma analog-to-digital converters (ADCs) can get such fine resolution across a variety of bandwidths? The secret lies in the digital filter. Delta-sigma ADCs are different from other types of data converters in that they typically integrate digital filters. In this first installment of a three-part series, I will discuss the purpose of…
In part 1 of this series, I explained how you can calculate the input voltage to an analog-to-digital converter (ADC) by multiplying the ADC’s output code by the least-significant bit (LSB) size using Equation 1:
To calculate the ADC’s LSB size, we used Equation 2:
Now that you know how to calculate the input voltage from the output code, let’s look at a few common application examples that use delta-sigma…
This post was co-authored with John Caldwell.
In the final installment of this five-part blog series, I will discuss pop/click noise in operational amplifiers (op amps) driving headphone loads, and some techniques to minimize them. The previous posts discussed power considerations for headphone loads, impedance of headphones, and sources of headphone amplifier stability and distortion…
