Thursday, June 21, 2018
Publication Date: 10/1/2007
Archive >  October 2007 Issue >  New Products > 

Step-Down Switching Regulators from Murata
Switching regulators.
Smyrna, GA — New 78SR Series 2A switching regulators that provide high operating efficiency for applications requiring 3.3V or 5V outputs, at 2 Amps or less, from 8 to 32V inputs have been introduced by Murata Power Solutions (formerly C and D's Power Electronic division). At a nominal 12V input, full-load efficiencies approach 96 percent for 5V models, and 93 percent for 3.3V models.

Unlike competitive products which typically suffer significant efficiency drops at low load currents, 78SR switching regulators operating at 12Vin and 25 percent load (0.5A) reportedly deliver efficiencies of 90 percent for 5V models, and 87 percent for 3.3V models.

The new switching regulators are available in two space-saving 0.8 x 0.85-in. (20.3 x 21.6mm) package styles: a standard vertical-mount SIP which occupies less than 0.09-in.2 (58mm2) of PC board real estate, and for applications with height restrictions, a horizontal-mount version with an installed height of less than 0.30-in. (7.6mm). Both packages have sturdy 0.025-in. (0.6mm) square pins that securely support the units without additional hardware or mounting tabs.

According to the company, the 78SR 2A Series has a 210kHz switching frequency, optimized low-loss layout, and an open frame construction. This allows for full-load operation from 9V, 12V, or 24V, supplies at ambient temperatures up to +70°C without heat sinks, forced-air cooling or temperature derating. This high efficiency can dramatically increase battery life in portable instrumentation and standby power applications, while also providing lower overall operating costs.

The new switching regulators offer several additional improvements over their linear counterparts. These include higher operating input voltage (32V vs. 28V), higher output current (2A vs. 1.5A), and significantly tighter output accuracy (±2 percent vs. ±5 percent). Excellent line and load regulation of ±0.35 percent and ±0.25 percent, respectively, allows for operation from poorly-regulated dc supplies. Unlike their linear counterparts they do not need any external input or output capacitors to provide stable, low-noise operation.

The switching regulators are low cost, pin and function compatible upgrades for competitive 0.5 to 2 Amp output, linear or switch-mode 3-pin modules. Applications include battery powered instruments, test equipment and fixtures, 12V/24V automotive, marine and recreational vehicles, military and aerospace electronics, industrial control instrumentation, and battery back-up power systems.

For more information, contact: Murata Electronics North America, Inc., 2200 Lake Park Drive, Smyrna, GA 30080-7604 770-436-1300 fax: 770-436-3030 Web:

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