Electronics-Lab.com Blog

Steve Taranovich writes:

Linear Technology Corporation announced the LT8705, a very high efficiency (up to 98%) synchronous buck-boost DC/DC controller that operates from input voltages above, below or equal to the regulated output voltage. This device has four feedback loops to regulate the input current/voltage, along with the output current/voltage.

Convert any input voltage from 2.8V to 80V into a fixed output voltage or output current - [Link]

The LTM4641 is a 4.5V to 38V input, 0.6V to 6V output, 10A step-down μModule regulator with comprehensive input and load protection features. The part monitors input voltage, output voltage and temperature conditions. If any user-adjustable trip thresholds are exceeded, the LTM4641 responds quickly (within 500ns in the case of an output overvoltage fault), ceasing operation and if necessary activating external switches to protect both input source and load. As a μModule regulator, the LTM4641 includes power MOSFETs, DC/DC controller, inductor, compensation and the protection logic circuits in a compact surface mount BGA package.

• Wide Operating Input Voltage Range: 4.5V to 38V
• 10A DC Typical, 12A Peak Output Current
• Output Range: 0.6V to 6V
• ±1.5% Maximum Total Output DC Voltage Error
• Differential Remote Sense Amplifier for POL Regulation
• Internal Temperature, Analog Indicator Output

LTM4641 – 38V, 10A DC/DC µModule Regulator with Advanced Input and Load Protection - [Link]

Here is a PDF document from Linear Technology, featuring current sense circuits for different applications, including High side, low side, level shifting, high and low voltage, fault sensing, etc: [via]

Sensing and/or controlling current flow is a fundamental requirement in many electronics systems, and the techniques to do so are as diverse as the applications them-selves. This Application Note compiles solutions to current sensing problems and organizes the solutions by general application type. These circuits have been culled from a variety of Linear Technology documents.

Current sense circuit collection - [Link]

The LTC®4000-1 is a high voltage, high performance controller that converts many externally compensated DC/DC power supplies into full-featured battery chargers with maximum power point control. In contrast to the LTC4000, the LTC4000-1 has an input voltage regulation loop instead of the input current regulation loop.

Features of the LTC4000-1’s battery charger include: accurate (±0.25%) programmable float voltage, selectable timer or current termination, temperature qualified charging using an NTC thermistor, automatic recharge, C/10 trickle charge for deeply discharged cells, bad battery detection and status indicator outputs. The battery charger also includes precision current sensing that allows lower sense voltages for high current applications.

LTC4000-1 – High Voltage/Current Controller for Battery Charging with Maximum Power Point Control - [Link]

www.computerhistory.org

Light, sound, temperature: the world is a symphony of vibrations. All around us is a world alive with continuously varying signals. These real world sensations are called analog signals to distinguish them from digital signals–which can only switch between 0 and 1 (on and off) and which exist only in a computer. Many systems have both analog and digital elements: a smartphone, for example, has both analog and digital parts and converts signals back and forth between the two continuously. Over half of the iPhone 4 is composed of analog circuits or systems.

Capturing these real-world signals and making them do amazing things is the domain of the analog circuit designer. Jim Williams, who was considered one of the best analog circuit designers in the world, suffered a stroke and passed away on June 12, 2011. Linear Technology, the company Jim worked for, has loaned the Computer History Museum Jim’s unique workbench so that visitors can learn about Jim and the fascinating world of analog circuit design.

An Analog Life: Remembering Jim Williams - [Link]

Designers of high availability systems frequently engineer redundancy into their power systems by paralleling two similar supplies with diodes (diode-OR) such that one can handle the load when the other fails. System reliability is further increased if both supplies operate simultaneously, each sharing half the load current. The LTC4370 is a first-of-its-kind current-sharing controller with reverse current blocking. The LTC4370 frees the designer from the limitations and complications of existing current-sharing methods to obtain a simpler, quicker, and space-saving solution for sharing between two supplies.

• Shares Load Between Two Supplies
• Eliminates Need for Active Control of Input Supplies
• No Share Bus Required
• Blocks Reverse Current
• No Shoot-Through Current During Start-Up or Faults

LTC4370 – Two-Supply Diode-OR Current Balancing Controller - [Link]

www.adafruit.com writes:

I’ve been doing a lot of power supply testing lately, using both switching a linear supplies. Since it’s not something I’ve had to do often in the past (I’m an apps person, not so much a test engineer) … I thought it was worthwhile to spend a bit of time digging around for app notes on accurately characterising linear and switching supplies.

AN 372-1 Power Supply Testing - [Link]

www.adafruit.com writes:

Analog Devices (who have a lot of great app notes locked up in their stable) have made available in PDF format enough good information and reading material to keep you busy for the rest of the winter while you wait for warm enough weather that you want to step outside again.  Their Linear Circuit Design Handbook has a lot of excellent material, and can also be ordered in printed format if you’re still a fan of a good old highlighter and notes in the margin like me.

Linear Circuit Design Handbook - [Link]

jumperone.com writes:

How to build your own linear adjustable power supply based on LM317. In this tutorial I’ll explain how linear power supply works, what parts it consists of and a lot of small details, like how to calculate smoothing capacitor value, or how to choose a transformer. Plus you’ll see how to build an actual power supply.

LM317 Simple Adjustable Linear Power Supply - [Link]

Linear Technology App Note #25 (PDF) — Jim Williams’ first cartoon, along with some great advice on designing switched-mode power supplies! Kent Lundberg has a great analysis of this appnote on his excellent Reading Jim Williams blog too. [via]

Switching Regulators for Poets - [Link]