We often discuss signal integrity in relation to digital data and communications — trying to ensure a high-speed digital signal isn’t corrupted during transmission— but analog signal integrity is also important. It could be simply trying to preserve the signal quality and accuracy within a PCB, or it could also cover the problem of transmitting an […]
FAQ
Understanding Modulation and Mixing
Modulation is considered to be a radio frequency (RF) technique which refers to modifying a periodic waveform with another waveform. For example, frequency modulation takes an RF “carrier” signal (sine wave) at say 88MHz and varies the frequency slightly, based on your “modulating” signal which will most likely be an audio signal up to 15kHz […]
How to achieve reverse polarity protection with ideal diodes
In battery operated devices which have removable batteries, you usually need to prevent the batteries from being connected the wrong way round to prevent damage to the electronics. If that is not possible by physical means you need to include some electronic protection. Physical protection can simply mean a polarized connector or a battery with […]
Going smaller & more portable with PCB embedded components
I recently came across the TDK SESUB-PAN-T2541 Bluetooth module. It is a complete bluetooth module consisting of a Texas Instruments CC2541 Bluetooth “System-on-Chip” (SoC) and the peripheral components required to use it – crystal, balun, and 15 other passive components. While it initially doesn’t sound that remarkable, when you look at the size (4.6mm x […]
Generating reference voltages
A “voltage reference” can mean anything from a simple resistive power supply rail splitter as a virtual ground for an opamp, to a high precision, low drift, low noise reference voltage for an analog to digital converter (ADC). For an opamp virtual ground, a couple of resistors and a capacitor can work and you may […]
By variation or from scratch: Electronics System Design
I frequently design new electronics systems. Sometimes these are variations of something I have done before and at other times they are completely new. If you are new to a particular product area and there is something similar in the marketplace then it is always a good idea to have a look at how other […]
Designing a Type-C electronically marked cable – Part 1
Summary This article discusses the newly emerging specifications, USB Type-C and Power Delivery (PD). Part 1 will introduce the USB 3.0 specification and its capabilities. Part 2 will explain various aspects related to the design of Electronically Marked Type-C cables. Introduction The USB Type-C is the newly introduced cable for USB. It is a simple, […]
Power supply noise
Power supply noise can come in more than one form. It could be switching noise from a switching regulator or switched mode power supply or noise from a linear regulator. While switching noise is to be expected, linear regulators are often assumed to be “quiet” but they may not be as quiet as you think. […]
Effects of intermodulation distortion in analog circuits
Unless you are an RF designer you probably haven’t thought much about intermodulation distortion. Harmonic distortion is more likely to have been of concern with low frequency circuits such as video and audio. Harmonic distortion, as the name suggests, creates unwanted components which are harmonically related to the signal. So, if you are amplifying 1kHz […]
Level Shifting Digital Logic Signals Part 2
I discussed the problem of level shifting logic signals a while ago but I noticed the recently introduced NXP AXP level shifters so thought it was worth revisiting the subject to see if these new devices will really help solving the problem of interfacing the increasingly varied power supply voltages in digital and mixed-signal circuits. […]
