編集後記

Welcome to the December issue of Analog Dialogue.

This December is nothing like the years before. Last year, I missed out on the Christmas markets in my hometown due to a business trip to California. This year, I looked forward to enjoying the festivities of Augsburg and Mering (my hometown). Glühwein (mulled wine), German sausages, gingerbread, Christmas songs, and a bit of snow while having a few days’ vacation would have been the best way to celebrate the season and the end of 2020.

Although the Christmas markets are canceled this year, the holiday offers the possibility of winter barbeques with neighbors or friends in the garden. We’ll be warming up wine and grilling sausages over an open fire. In this spirit, I wish you a relaxing end of the year and a good start to 2021, with the hope that it will not be as challenging. We will continue with Analog Dialogue, now approaching its 55th year, and we look forward to updating you on the latest technologies, applications, and solutions from Analog Devices.

Back to the articles from Analog Dialogue.

UART, or universal asynchronous receiver-transmitter, is one of the most used forms of device-to-device communication protocol. UART can work with many different types of serial protocol to transmit and receive serial data. In serial communication, data is transferred bit by bit using a single line or wire. In two-way communication, two wires are used for successful serial data transfer. This article discusses the fundamental principles when using UART, which primarily includes packet transmission, standard frame protocol, and customized frame protocols that are value added features for security compliance when implemented during code development.

The next article’s topic relates to USB charging ports, which have become an essential part of the modern vehicle infotainment system. Passengers have become increasingly accustomed to using USB ports to power their smartphones or other portable devices and use them for entertainment. Thus, today’s USB charging ports must meet a variety of system requirements with respect to power, data transmission, and robustness, while maintaining adaptability to the continuously changing portable device markets. This article describes system solutions that can meet this criteria.

Our next article is Part 2 of the “Interleaved Inverting Charge Pump” series. In Part 1, we introduced a unique method to generate a low noise negative rail from a positive supply and then derived the equations governing its operation. In Part 2, we give a practical example of this interleaved inverting charge pump (IICP) implementation with Analog Devices’ new ADP5600. We first compare the voltage ripple and radiated emissions of the ADP5600 to a standard inverting charge pump. Then we use the equations from Part 1 to optimize the IICP performance and develop a complete solution for powering a low noise phased array beamforming circuit.

Galvanically isolated industrial control modules cover the standard analog output voltage and current ranges of ±5 V, ±10 V, 0 V to +5 V, 0 V to +10 V, 4 mA to 20 mA, and 0 mA to 20 mA. One approach to creating these modules is a discrete design to convert the digital signals from the microcontroller to analog and provide external components for the different analog outputs. However, discrete designs may be less optimal than integrated solutions. This leads into our RAQ, which describes how to design a microcontrolled, isolated, 16-bit output module using three chips.

Continuing from November’s StudentZone, we introduce a current mirror that has an output that has been desensitized to variation in input current. In such a case, it is helpful to examine the behavior of a zero-gain amplifier from another perspective: using MOS transistors. Antoniu and Doug guide us through this next student activity.

And as we have for 54 years, we invite you to be part of the dialogue in Analog Dialogue. You can get in touch through our blog, Facebook page, or email. Let us know how we’re doing and what you’d like to see from us in the coming months.