Murata Expands Switching Regulator DC/DC Converter Family

Murata has added a 12 V model to its OKI-78SR series of non-isolated switching regulator DC/DC power converters for embedded applications. The fixed single output converter offers both tight regulation and high efficiency directly at the power usage site, and is a direct plug-in replacement for TO-220 package 78xx series linear regulators.

oki-78sr-12-prRated at 12V/1A, when powered from a 24V source, the OKI-78SR-12/1.0-W36-C converter’s efficiency is a very high 95%, eliminating the need for a heatsink that adds cost and increases complexity in the design and manufacturing processes. Cleverly packaged in the form of a three-terminal 78xx linear regulator, the converter operates from a source voltage of 15 to 36V and is available in both vertical and horizontal mounting options. The package size is just 10.4 x 7.62 x 16.5mm (0.41 x 0.3 x 0.65 inches).

Murata’s OKI-78SR series is suitable in a wide range of applications, including computing, networking, telecommunications, industrial, aerospace and rail. Indeed, it is ideal for any application where the ambient temperature ranges from -40 to 85°C, which has a source/system voltage in the range of 15 to 36 Vdc, and where the output requirement is for 12 V at 1 A. Standard features include a factory-set Vout at 12 Vdc, short-circuit/over-current protection, UL/EJ/IEC 60950-1, second edition safety approvals and RoHS compliance.

The OKI-78SR series incorporates advanced assembly techniques and the latest fixed switching frequency technology for power conversion available today. The optional packaging configurations, safety features, high reliability, state-of-the-art figures for efficiency, thermal management, dynamic load response, industry standard package and OCP protection features offer an unmatched level of performance.

Murata Power Solutions | www.murata-ps.com

45 W Photovoltaic DC/DC Converter Has 150-1500 VDC Input Range

Aimtec has introduced its AM45W-NS series feature an ultra-wide 150-1500VDC input range with dual separated outputs.The AM45W-NST with an output power of 45W has the largest input voltage range on the market, ranging from 150-1500VDC and can reach a maximum of 1600VDC for up to 1 second. In addition, the new series comes equipped with a regulated dual output signal and a high input to output isolation of 4000VAC tested over a 60 second cycle during manufacturing.

200_sq_press

The series also supports 3 Nominal input voltage levels of 200, 850 & 1400VDC and separates the output voltages to two ±15VDC outputs. Operating temperature are within the -40°C to 85°C range. This series is designed to meet the solar energy conversion into DC electricity requirements for Photovoltaic Power Generation and High-voltage Inverters.

The AM45W-NST, is available in a 5.69 x 4.13 x 1.57-inch (144.50 x 105.00 x 40.00 mm) metal enclosed package with screw terminals for easy wire connection. Many safety features such as Over Voltage and Over current output protection, Continuous Short Circuit Protection, Input Under Voltage Lockout and Reversed connection protection come standard. Finally, this addition also features a 2 second maximal start-up time for quick response times.

Aimtec | www.aimtec.com

Ultra-Small SWIFT Step-Down Converter

Texas Instruments (TI) recently introduced the industry’s first 12-V, 10-A, 10-MHz series-capacitor buck converter that achieves more than 50 A/cm3 in current density, which is 4× higher than any other 12-V power management component or solution on the market. The TPS54A20 SWIFT synchronous DC/DC converter’s topology enables high-frequency operation at up to 5 MHz per phase without special magnetics or compound semiconductors, which you can use for 8-to-14-V input and 10-A output applications. By using the step-down converter together with TI’s WEBENCH Power Design tool, you can get your space- and height-constrained point-of-load (POL) telecom and networking power-supply designs to market faster.TI TPS54A20

TPS54A20 key features and benefits:

  • Two-phase, series-capacitor DC/DC buck topology that merges a switched-capacitor circuit with a multiphase buck converter
  • Small HotRod quad flat no-lead (QFN) packaging
  • Inexpensive, tiny 2- to 5-MHz inductors enable a 131-mm2 solution size that consumes 50% less area than similar 500-kHz DC/DC converter designs.
  • At under 2 mm tall, the reduced size, weight, and bill of materials (BOM) allows for the placement of tiny 10-A voltage regulators on the back side of a PCB
  • A 14-ns minimum on-time allows for 4-/7-/10-MHz operation without compromising efficiency or EMI performance.

The new DC/DC converter is available in volume.  The TPS54A20 costs $3.25 in 1,000-unit quantities. Order the 4-MHz, 10-ATPS54A20EVM-770 synchronous dual-phase converter evaluation module and download the PSpice transient models.

Source: Texas Instruments

1.5-A Synchronous Step-Down DC/DC Converter Delivers 93% Efficiency

Linear Technology’s new LT8608 is a 1.5-A, 42-V input synchronous step-down switching regulator that delivers 93% efficiency while switching at 2 MHz. It is well suited for avoiding critical noise-sensitive frequency bands (e.g., AM radio) while using a compact footprint. Burst Mode operation keeps quiescent current under 2.5 µA in no-load standby conditions. Its 3-to-42-V input voltage range makes it ideal for automotive applications that must regulate through cold-crank and stop-start scenarios with minimum input voltages as low as 3 V and load dump transients in excess of 40 V. Its internal 2-A switches can deliver up to 1.5 A of continuous output current.Linear 8608

The LT8608 maintains a minimum dropout voltage of only 200 mV (at 500 mA) under all conditions. Spread-spectrum frequency modulation and special design techniques offer low EMI operation. In addition, a fast minimum on-time of only 45 ns enables 2-MHz constant frequency switching from a 16-V input to a 1.5-V output. The LT8608’s 10-lead thermally enhanced MSOP package and high switching frequency keeps external inductors and capacitors small for a thermally efficient footprint.

The LT8608’s features and specifications include:

  • Wide input voltage range: 3 to 42 V
  • Ultralow Quiescent Current Burst Mode operation:
    • Less 2.5-µA IQ Regulating 12 VIN to 3.3 VOUT
    • Output Ripple less than 10 mVPP
  • High Efficiency 2-MHz Synchronous Operation:
    • 93% Efficiency at 0.5 A, 5 VOUT from 12 VIN
  • 1.5-A Maximum Continuous Output Current
  • Fast Minimum Switch-On Time: 45 ns
  • Adjustable and Synchronizable: 200 kHz to 2.2 MHz
  • Spread-Spectrum Frequency Modulation for Low EMI
  • Allows Use of Small Inductors
  • Low Dropout
  • Peak Current Mode Operation
  • Accurate 1-V Enable Pin Threshold
  • Internal Compensation
  • Output Soft-Start and Tracking
  • Small 10-Lead MSOP Package

Source: Linear Technology

Synchronous Step-Down Regulator with Ultralow DCR Current Sensing

Linear Technology Corp. recently introduced the LTC7130, which is a constant frequency peak current mode synchronous step-down DC/DC converter with temperature-compensated ultralow DCR current sensing and clock synchronization. According to Linear Technology, the LTC7130 “offers the ability to directly parallel multiple ICs for higher current capability” and “also enhances the signal-to-noise ratio of the current sense signal, enabling the use of a very low DC resistance power inductor to maximize efficiency in high current applications.”Linear LTC7130

The LTC7130’s features and specifications:

  • A wide VIN Range of 4.5 to 20 V
  • High efficiency (up to 95%)
  • Proprietary current mode architecture
  • High current parallel operation
  • Ultralow DCR current sensing with temperature compensation
  • Programmable output current limit
  • High-speed differential remote sense amplifier
  • ±0.5% Output voltage regulation accuracy
  • Output short-circuit protection with soft recovery
  • Programmable and synchronizable fixed frequency from 250 to 770 kHz
  • EXTVCC for reduced power dissipation
  • Fault Indicator for output UV/OV conditions

The LTC7130 is available in a thermally enhanced 6.25 mm × 7.5 mm × 2.22 mm BGA package (RoHS lead-free and leaded SnPb (63/37) finishes). The E-and I-grades are guaranteed in the 40°C to 125°C operating junction temperature range. The 1,000-piece price starts at $7.95 each for the E grade.

Source: Linear Technology

60-V LED Driver with Internal 4-A Switch & PWM Generator

Linear Technology’s LT3952 is a current mode step-up DC/DC converter with an internal 60-V, 4-A DMOS power switch. It is specifically designed to drive high power LEDs in multiple configurations. It combines input and output current regulation loops with output voltage regulation to operate as a flexible current/voltage source.  The LT3952’s 3-to-42-V input voltage range makes it ideal for a wide variety of applications, including automotive, industrial, and architectural lighting.Linear 3952

The LT3952 can drive up to 16 350-mA white LEDs from a nominal 12-V input, delivering in excess of 15 W. It incorporates a high side current sense, enabling its use in boost mode, buck mode, buck-boost mode or SEPIC topologies. Internal spread spectrum frequency modulation minimizes EMI concerns. The LT3952 delivers efficiencies of over 94% in the boost topology, eliminating the need for external heat sinking, and internal LED short-circuit protection enables added reliability required in most applications. A frequency adjust pin permits the user to program the switching frequency between 200 kHz and 3 MHz, optimizing efficiency while minimizing external component size and cost. The LT3952 delivers over 90% efficiency while switching at 2 MHz in a tiny solution footprint. The LT3952 provides a very compact high power LED driver solution in a thermally enhanced TSSOP-28E package.

The LT3952 has a gate driver for a PMOS LED disconnect switch, delivering dimming ratios of up to 4,000:1 using an external PWM signal. For less demanding dimming requirements, the CTRL pin can be used to offer a 10:1 analog dimming range and an internal PWM generator can be used for 5:1 dimming. The LT3952’s fixed frequency, current-mode architecture offers stable operation over a wide range of supply and output voltages. Output short-circuit protection and open LED protection enhance system reliability. Other features include frequency synchronization, spread spectrum frequency modulation, programmable VIN undervoltage and overvoltage protection, and an input current limit and monitor.

The LT3952EFE is available in a thermally enhanced 28-lead TSSOP package. Three temperature grades are available, with operation from –40°C to 125°C (junction) for the extended, and industrial grades, and a high temperature grade of –40°C to 150°C. Pricing starts at $3.95 each in 1,000-piece quantities and all versions are available from stock. For more information, visit www.linear.com/product/LT3952

Source: Linear Technology