The LT8614 is a 4A, 42V input capable synchronous step-down switching regulator. A unique Silent Switcher architecture reduces EMI/EMC emissions by more than 20dB, well below the CISPR 25 Class 5 limit. Even with switching frequencies in excess of 2MHz, synchronous rectification delivers efficiency as high as 96% while Burst Mode operation keeps quiescent current under 2.5μA in no-load standby conditions. Its 3.4V to 42V input voltage range makes it ideal for automotive and industrial applications.
LT8614 – 42V, 4A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current - [Link]
This is a DC-DC step-up converter based on LM2585-ADJ regulator manufactured by Texas Instruments. This IC was choosen for it’s simplicity of use, requiring minimal external components and for it’s ability to control the output voltage by defining the feedback resistors (R1,R2). NPN switching/power transistor is intergrated inside the regulator and is able to withstand 3A maximum current and 65V maximum voltage. Switching frequency is defined by internal oscillator and it’s fixed at 100KHz.
LM2585 12V to 24V @ 1A Step-up switching regulator - [Link]
Here is an app note from Maxim describing the various SMPS regulator topologies for battery powered systems:
This tutorial presents an overview of regulator topologies for battery-powered equipment. The discussion covers linear regulators, charge pumps, buck and boost regulators, inverters, and flyback designs. The importance of peak current is explained, and schematics of each topology are shown.
App note: Regulator topologies for battery-powered systems - [Link]
This collection of circuits provides step-up voltage regulation for single cell and dual cell Alkaline, NiMH, and Li+ battery driven applications. Regulate your battery driven app with an efficient converter from Maxim.
Your battery-powered application needs regulation. This collection of circuits provides step-up voltage regulation for single- and dual-cell Alkaline, NiMH, and Li+ battery-driven applications.
A simple 1A step-up converter in a tiny WLP package that can be used in any single-cell Li-ion application. This IC provides protection features such as input undervoltage lockout, short circuit, and overtemperature shutdown.
The input voltage of these circuits range from 0.7V to VOUT and they have a preset, pin-selectable output for 5V or 3.3V. The outputs can also be adjusted to other voltages using two external resistors.
The TS3310 is a low power boost converter with an industry-leading low quiescent current of 150nA, enabling ultra long battery life in systems operating from a variety of battery sources. The TS3310 is the industry’s only boost converter to specify its no-load supply current with an actively switching boost engine, providing a more accurate picture of supply current during normal operation. The TS3310 boosts input voltages from 0.9V-3.6V to one of eight user-selectable output voltages ranging from 1.8V to 5.0V. The TS3310 includes two outputs: (a) an always-on primary output and (b) a user-enabled, load-switched secondary output designed to power burst-on loads operating at low duty cycles, such as a ZigBee radio.
TS3310: A True 150-nA IQ, 0.9-3.6VIN, Selectable 1.8-5VOUT, High-Efficiency Instant-ON™ Boost Converter - [Link]
The MAX17515 is a fixed-frequency, step-down power module in a thermally efficient system-in-package (SIP) package that operates from a 2.4V to 5.5V input supply voltage and supports output currents up to 5A. The device includes switch-mode power-supply controller, dual n-channel MOSFET power switches, a fully shielded inductor, as well as compensation components. The device supports 0.75V to 3.6V programmable output voltage. The high level of integration significantly reduces design complexity, manufacturing risks, and offers a true “plug-and-play” power-supply solution, reducing the time to market.
MAX17515 – 5A, 2.4V to 5.5V Input, High-Efficiency Power Module - [Link]
Which are the key parameters for MOSFETs in typical DC/DC converter applications. by Publitek European Editors:
The silicon MOSFET has become a key component in the design of DC/DC converters, providing the high-speed switching and current-handling capability needed to implement high-efficiency, pulse-width-modulation-based control strategies. The drive towards higher efficiency is placing more intense demands on MOSFETs, particularly in designs that have constraints on size, reducing the amount of space that can be given over to heatsinks and other cooling assistance.
The trends are pushing towards the use of MOSFETs that offer reduced Rds(on), as well as offering low switching losses through good charge-storage characteristics. This article will examine a number of the key parameters for MOSFETs in typical DC/DC converter applications.
MOSFETs Target the Major Efficiency Losses in DC/DC Converters - [Link]
The LT3690 is an adjustable frequency monolithic buck switching regulator that accepts input voltages up to 36V. A high efficiency 90mΩ switch is included on the device along with the boost diode and the necessary oscillator, control, and logic circuitry. The internal synchronous power switch of 30mΩ increases efficiency and eliminates the need for an external Schottky catch diode. Current mode topology is used for fast transient response and good loop stability. Shutdown reduces input supply current to less than 1μA. The low ripple Burst Mode maintains high efficiency at low output currents while keeping output ripple below 15mV in typical applications.
LT3690 – 36V, 4A, 1.5MHz Synchronous Step-Down Switching Regulator with 70μA Quiescent Current- [Link]
International Rectifier introduced the IR3823 SupIRBuck integrated voltage regulator designed for space-constrained, energy efficient netcom, server and storage applications. Steve Taranovich writes:
The IC delivers up to 3A a 3.5×3.5mm package. Efficiencies in excess of 97.5% are obtainable for designs converting power from a 6V input to a 4.8V output. The extremely high initial efficiency allows switching at up to 1.5MHz from a 12V supply to enable a complete 3A power supply solution in less than 130mm2. Featuring constant frequency and virtually jitter-free operation with synchronization capability, the new device is well suited to noise-sensitive applications, while the higher bandwidth reduces component count to shrink PCB footprint. A tri-level selectable soft-start feature is also offered for ease of sequencing.
IR’s integrated voltage regulator with 97.5% efficiency in a 3.5×3.5mm package - [Link]
By Ashok Bindra:
A buck-boost DC/DC converter delivers a regulated output voltage even when the input voltage is below or above that required by the load. Buck-boost converters adequately serve the needs of battery-powered consumer devices where the required input range is rather narrow; in many cases from 1.8 to 5.5 VDC. However, the situation is different when it comes to industrial and automotive applications where input voltages can vary over a very wide range.
For example, the automotive battery presents one of the most challenging inputs to a power supply. While its nominal voltage can vary from 10.6 to 15 V, depending on the battery’s state of charge, the ambient temperature, and the alternator, cold-crank conditions can push the rail below 4 V and line transients can produce 40 V spikes. That means it can vary from less than 4 V to over 40 V. In addition, experts say that the automotive power rail is also subject to a variety of dynamic disturbances produced by changes in the engine, transitioning loads, and inductive transients in the wiring harness.
Buck-Boost DC/DC Handles Wide Input-Voltage Range - [Link]