Electronics-Lab.com Blog

The LT3651 enables fast charging of Li-Ion/Polymer batteries by delivering up to 4A of continuous charge current with minimal power loss. This is due to its high efficiency switchmode topology, including on-chip synchronous MOSFETs. Its autonomous operation means no microcontroller is necessary and the device integrates an onboard C/10 or timer charge termination. The LT3651’s programmable input current limit with PowerPathTM control regulates charge current to maintain a constant supply current, preventing the input supply from collapsing.

• Wide Input Voltage Range: Up to 32V (40V Absolute Maximum)
• Programmable Charge Current Up to 4A
• Selectable C/10 or Onboard Timer Termination
• Dynamic Charge Rate Programming/Soft-Start
• Programmable Input Current Limit

LT3651 – Monolithic 4A High Voltage 1 Cell Li-Ion Battery Charger - [Link]

Publitek European Editors writes:

Many security and motion detector systems rely on small, semi-autonomous nodes that are easy and simple to install. This implies the use of a battery-based power source and low-power operation in order to minimize the number of battery changes during the lifetime of the product.

Over its lifetime, the output voltage of a battery falls, with the biggest decline when the charge is nearing full depletion. A converter type that can accommodate this change in voltage but can still provide relatively high voltages for sensors and RF transmitters is the buck-boost converter – it operates the buck part of the circuit when the battery is fresh, moving to boost operation when the voltage falls below the threshold of the electronic circuitry it powers. A number of vendors have developed integrated buck-boost converters optimized for battery systems

Buck-Boost Converters Help Extend Battery Life for Motion Detection - [Link]

Publitek European Editors :

The low-dropout regulator (LDO) has long been the choice for buck voltage conversion not only where cost is an issue but where noise performance is critical.

The brainchild of Linear Technology co-founder Robert Dobkin, conceived when he worked at National Semiconductor, the core architecture of the regulator is very simple but effective. Dobkin took a fixed-ratio voltage regulator and adapted it so that its output could be adjusted using a voltage divider on the output.¹

In the classic linear regulator, a transistor acts as half of a potential divider. Its output voltage is to control a feedback circuit that has control over the transistor’s gate in the case of a MOSFET, which is normally the case for an LDO regulator. The constant control via feedback over gate voltage provides a stable output voltage at a level set by the reference circuitry. Because of the use of a voltage divider structure, the linear regulator can produce only a voltage that is lower than that of the input. Older regulator circuits could experience a drop of 2 V or more. LDOs were devised to provide easier control over the output voltage and to constrain this dropout voltage to less than 2 V.

Linear Regulators Drive Noise Down - [Link]

The TPS22966 is a small, ultra-low RON, dual channel load switch with controlled turn on. The device contains two N-channel MOSFETs that can operate over an input voltage range of 0.8V to 5.5V and can support a maximum continuous current of 6A per channel. Each switch is independently controlled by an on/off input (ON1 and ON2), which is capable of interfacing directly with low-voltage control signals. In TPS22966, a 220-Ω on-chip load resistor is added for quick output discharge when switch is turned off.

TPS22966 – 6A Dual Load Switch with Controlled Turn On - [Link]

Dual-Resonant Solid State Tesla Coil (DRSSTC). Shane writes – [via]

It’s been a long time since I built something that isn’t a robot, a motor controller, anelectric vehicle, or a multirotor. Also, the Edgerton Center Summer Engineering Workshop (responsible for the DIY Segway, BWD Scooter, Cap Kart, and tinyKart) isn’t running this year, so I feel the need to take on a summer project of my own. Inspired by the work of MITERS regulars Tyler, Daniel, Bayley, and Ggy, I’m attempting to build..

Specifically, I’m building a Dual-Resonant Solid State Tesla Coil (DRSSTC). Tesla coils generate high voltage and pretty sparks using electromagnetic induction. They’re loosely-coupled air-core transformers where the world is your output load. (Or just the toroidal “top load” and the air around the Tesla coil.) “Dual-resonant” implies that both the primary and the secondary form RLC series resonant circuits, tuned to about the same natural frequency. “Solid state” implies that the primary circuit is driven (near resonant frequency) by transistors, usually IGBTs although I will be starting with MOSFETs.

Building a Dual-Resonant Solid State Tesla Coil (DRSSTC) - [Link]

The TPS54160 device is a 60-V, 1.5-A, step down regulator with an integrated high-side MOSFET. Current mode control provides simple external compensation and flexible component selection. A low ripple pulse skip mode reduces the no load, regulated output supply current to 116 µA. Using the enable pin, shutdown supply current is reduced to 1.3 µA.

2.5MHz DC/DC converter protect against 65-V transients - [Link]

Rectifier circuit with very low voltage drop featuring a P-channel MOSFET  - [via]

Different ways you can protect your circuit from backwards power connections. Diodes, schottky diodes and P channel MOSFETs.

P-FET Reverse voltage polarity protection tutorial - [Link]

www.adafruit.com writes:

Having a hard time trying to figure out whether that FET can handle enough current for your project? AN11158 from NXP might help clarify some of the many parameters that you need to take into account that are often overlooked.  The Safe operating area, for example, is an important one that often gets skipped and people just look at the best-case scenario marketing numbers on the front page of the datasheet: “The Safe Operating Area (SOA) curves are some of the most important on the data sheet. The SOA curves show the voltage allowed, the current and time envelope of operation for the MOSFET. These values are for an initial Tmb of 25°C and a single current pulse. This is a complex subject which is further discussed in the appendix (Section 3.1).”

Understanding power MOSFET data sheet parameters - [Link]

Derek Wolfe writes:

This circuit allows a simple switch or a low voltage pulse (5V for example) to control a large dc load. There’s a good explanation of MOSFET transistors and how to use them as a switch here. This is great for connecting a large load to a microcontroller or other logic circuit. Power MOSFET transistors are perfect for this application and can handle high voltage and current (100V, 77A for the NTP6411). This design would be able to power almost any load you can think of (probably even your car).

N-Ch Power MOSFET Switch - [Link]

coremelt.net writes:

With this tool you can test various electronic components like diodes, LEDs, all kinds of transistors (PNP, NPN, several types of MOSFETs), capacitors, resistors as well as triacs and thyristors. It will show you several physical characteristics after the test was completed, like forward voltages, (gate) capacity and amplification factor. More over, it will show the polarity of the component and identifies the several pins of a package. A very nice and sophisticated project I host for Markus Frejek. I’ve done an additional layout for the device you can see on the left side. This project has found a lot of fans, including myself. The device is powered by an AVR ATmega 8 MCU.

Component tester - [Link]