A diode is a passive component made with semiconductor materials (a chip) that conducts current flowing in one direction but does not conduct current flowing in the opposite direction. The symbol for a diode (to the right in Figure 1) looks something like an arrow pointing in the direction of the forward current. Current flows […]
FAQ
How to specify the proper Peltier module for your design
The latest generation of Peltier cooling modules can be a powerful addition to a designer’s thermal management toolbox. Robust and reliable, they can cool an IC or various other components – such as an LED or laser diode – to a target temperature and ensure stability even if the load changes rapidly. The modules are […]
Load switches, Part 2: IC implementations and benefits
Part 1 of this FAQ looked at the need for the load-switch function for a circuit’s DC rails, the basic implementation using a MOSEFT and driver, and the limitations of this approach. Part 2 looks at what are referred to as load switches, which in this context means ICs designed to implement the load-switch function, […]
Load switches, Part 1: Basic role and principle
Load switches are used to enable/disable power to selected ICs or circuit subsections. Although they don’t get much attention, they are useful for both saving power as well as management of multiple power rails. This FAQ will discuss their function, basic design, advanced IC implementations, and additional benefits of IC load switches. Q: What is […]
Here’s what happens when lithium-ion batteries are drastically overcharged
Lithium batteries have a high energy density so they can store a lot of energy in a small volume. But they can go up in smoke when bad things happen. Recently we recorded a short video to show what can happen during one of those bad things – overcharging. Excessive charging can bring on thermal […]
Voice-coil actuators, Part 2: Application issues
Part 1 looked at the basic of the VCA. Part 2 looks at operation in more detail along with applications, as well as a comparison to the solenoid. Q: What equation governs the behavior of a VCA? A: As with most magnetic-coil devices, it’s the Lorentz force equation. This shows that the force generated is […]
Voice-coil actuators, Part 1: Principle basics
When designers need a modest amount of motion and power, they naturally think of a motor. That makes sense since there’s often a brushed, brushless, or stepper motor that can meet the objectives, sometimes with some necessary add-on gearing. Or they may think of a solenoid for impact-type linear motion. This FAQ looks at another […]
Wireless charging, Part 2: Implementation
Part 1 of this FAQ looked at the overall context of wireless charging of personal devices. This part looks in more detail at the approaches to wireless charging and the implementation specifics. Q: What approaches are available for wireless charging? A: There are three basic topologies: single-coil inductive, multi-coil inductive, and resonant. Q: What are […]
Wireless charging, Part 1: Context
Wireless charging of devices is a hot and growing area. This FAQ explores the rationale and options for implementing this form of energy transfer, storage, and charging. Q: What is wireless charging? A: It consists of two functions which are closely linked. The first is the transmission of electricals power wirelessly from a transmitting source […]
Parasitic capacitance, inductance, and displacement current
When two electrical conductors are physically close, carry a charge, and there’s a voltage potential between them, they create a virtual capacitor between them, even if the conductors are insulated. The virtual capacitor between them is known as parasitic or stray capacitance. This can happen anywhere but is most troublesome between traces on printed circuit […]