Picking up where we left off in Part 1, we need to explore some methods to mitigate problems caused by unpredictable ground currents. Let’s start with some simplification, although we may need to first complicate things to then simplify them. First, let’s arrange a massive ground plane around the analog circuitry on the PC board. […]
Avoid ground loops in mixed-signal circuits part 1
Ground loops can degrade circuit performance and ruin your day. Follow these tips to prevent them from occurring in circuits that use analog and digital components. A typical mixed-signal system — a system comprised of digital logic and analog circuitry — uses multiple power supplies. Typical voltages include +5 VDC, +3.3 VDC, and/or +1.8 VDC […]
Power-supply supervisors keep circuits in check: part 2
Is my power supply OK, and what if it isn’t? Is my microprocessor still working? In part 1, we examined the operation of power supply supervisory ICs that can detect when the supply voltage is too low, and what might happen if so. We will continue that analysis and then consider ways to keep an […]
Power-supply supervisors keep circuits in check: part 1
Is my power supply OK? What about my microprocessor? What if something goes wrong? Simulations show what happens if DC voltage drops. Microprocessors can behave in unwanted ways when their power supplies don’t deliver the expected voltage. Errors can occur, circuits can unexpectedly reset or even go rogue. To prevent such problems, many devices use […]
How op amps work and why you should use them: part 3
Operational amplifiers (op amps) are almost the perfect amplifier. As long as you keep a few important details in mind, their imperfections will seem invisible. In part 1, Equations 2 and 3 used the term AV for the voltage gain of the simple noninverting amplifier shown in Figure 1. The equations use α for the […]
How op amps work and why you should use them: part 2
Operational amplifiers (op-amps) are almost the perfect amplifiers. As long as you keep a few important details in mind, they will seem perfect. In part 1, I gave a simplified explanation of how an op amp, functioning as a servo amplifier, amplifies a small signal by comparing it to the attenuated signal from the amplifier’s […]
How op amps work and why you should use them: part 1
Operational amplifiers (op amps) may initially look intimidating, but with a bit of study, they can be easily understood and used in a variety of applications. Op amps can be thought of as a perfect amplifier in a black box. When we create a design using an op amp, we initially presume that the device […]
