by Steve Taranovich @ edn.com:
With many switching buck regulators on the market today that are capable of improving an automotive system design it is hard to choose the optimum one for your design. I patricularly like a new Linear Technology solution, the LT8609, a 2A, 42V input synchronous step-down switching regulator because it is unique in that it does not require an external flyback diode (sometimes called a snubber diode, freewheeling diode, suppressor diode, suppression diode, clamp diode or catch diode) which is a diode used to eliminate flyback, which is the sudden voltage spike seen across an inductive load when its supply voltage is suddenly reduced or removed. This makes for less external components.
Linear Technology 2A buck converter is 93% efficient at 2MHz - [Link]
Micrel’s family of low-profile step-down power modules integrates a synchronous buck regulator with an inductor into a 2.5×3×1.1-mm QFN package for the 1-A MIC33163/33164 and a 2.5×3×1.9-mm QFN package for the 2-A MIC33263/33264. The modules offer 100% duty cycle operation and accommodate an input voltage range of 2.7 V to 5.5 V.
DC/DC buck power modules fit tight spaces - [Link]
The TPS65262 is a monolithic triple synchronous step-down (buck) converter with 3-A/1-A/1-A output current. A wide 4.5- to 18-V input supply voltage range encompasses the most intermediate bus voltage operating off 5-, 9-, 12-, or 15-V power bus. The converter, with constant frequency peak current mode, is designed to simplify its application while giving designers options to optimize the system according to targeted applications.
TPS65262 – Triple Synchronous Step-Down Converter with 200mA/100mA Dual LDOs - [Link]
I explain buck converters (a type of switch mode power supply) and how to build a 5V 5A power supply using an LM2678.
How to build a switch mode power supply! DC-DC buck converter tutorial! - [Link]
The PicoBuck is a small and inexpensive 3-channel LED driver. It employs constant-current buck driving which approaches an efficiency of 95% (theoretical). It’s based on AL8805 LED Lighting Buck Driver from Diodes Inc.
PicoBuck – RGB LED Driver - [Link]
Industry’s Only 60V, 2.5A Internal FET Synchronous Buck Converter
The MAX17503 high-efficiency, high-voltage, synchronously rectified step-down converter with dual integrated MOSFETs operates over a 4.5V to 60V input. It delivers up to 2.5A and 0.9V to 90%VIN output voltage. Built-in compensation across the output voltage range eliminates the need for external components. The feedback (FB) regulation accuracy over -40°C to +125°C is ±1.1%. The device is available in a compact (4mm x 4mm) TQFN lead(Pb)-free package with an exposed pad. Simulation models are available.
The device features a peak-current-mode control architecture with a MODE feature that can be used to operate the device in pulse-width modulation (PWM), pulse-frequency modulation (PFM), or discontinuous-conduction mode (DCM) control schemes. PWM operation provides constant frequency operation at all loads, and is useful in applications sensitive to switching frequency. PFM operation disables negative inductor current and additionally skips pulses at light loads for high efficiency. DCM features constant frequency operation down to lighter loads than PFM mode, by not skipping pulses but only disabling negative inductor current at light loads. DCM operation offers efficiency performance that lies between PWM and PFM modes. The low-resistance, on-chip MOSFETs ensure high efficiency at full load and simplify the layout.
4.5V-60V, 2.5A, High-Efficiency, Synchronous Step-Down DC-DC Converter with Internal Compensation - [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]
A Switch Mode Power Supply circuit collection from Linear Technology. It covers 12 basic SMPS circuit categories: Battery, Boost, Buck, Buck-Boost, Flyback, Forward, High Voltage, Multioutput, Off Line, Preregulator, Switched Capacitor and Telecom. [via]
Switching regulator circuit collection - [Link]
Sam Davis writes:
Individual solar-panel systems produce dc power for remote applications while also storing energy in a rechargeable battery supported by a battery-charger IC.
In non-utility grid applications solar panels produce dc power for emergency roadside telephones, navigation buoys, and other remote loads. Virtually all 12-V-system solar panels comprise a series of photovoltaic cells that have a maximum output power of less than 25 W. In producing this power the solar-panel system uses a battery to provide power when the panel is “dark.” The rechargeable battery can supply power for long periods of time, requiring a charger that can properly operate a solar panel.
Meeting this need is Linear Technology’s LT3652 monolithic buck-charger IC, which operates with a single solar panel. The IC uses average-current-mode control-loop architecture to provide constant current/constant voltage (CC/CV) charge characteristics with a programmable charge current. The charger can be programmed to produce a 14.4-V float voltage. Housed in a 3- × 3-mm DFN-12 package, the IC can charge a variety of battery configurations, including up to three Li-Ion/Polymer cells in series, up to four Lithium Iron Phosphate (LiFePO4) cells in series, and sealed lead-acid batteries up to 14.4 V.
Power-Tracking Battery-Charger IC Supports Solar-Power Systems - [Link]
Giorgos Lazaridis writes:
Some time ago i published a theory page regarding the LED driving and controlling methods. These methods were all linear regulators, very simple to make but very inefficient -in terms of power consumption- for high current applications. The idea was to use this theory page as an entrance level for the SMPS LED drivers.
The first SMPS (Switching Mode Power Supply) LED driver that i made is a Buck-Regulating LED Driver using a chip from Allegro Microsystems, the A6210. I was provided some samples from Farnell for testing and prototyping, along with some other cool staff. Do not forget to pay a visit to Farnell on-line store and Element14 website.
The A6210 can drive up to 3A load with constant current, with switching frequencies up to 2 MHz and supply voltage from 9 to 46 volts. It has additionally an optional PWM input to control the brightness of the LED. The sense voltage is limited to 0.18 volts for higher efficiency, since the power dissipation on this sense resistor is minimal. I will be using a 10-12V 1A 10 Watt LED, powered from 24 VDC supply.
High Efficiency High Current LED Buck Driver using the A6210 - [Link]