Power-Saving Products: Smart Designs Lead To Dim(mer) Results

Whether it’s a cost measure or going greener, cutting power consumption is foremost on the minds of most engineers throughout the industry. As such, advances continue to pour in along these lines. Here are some of the latest newsmakers.

Tests on a VoIP processor, the SC14450, designed by German chip company SiTel Semiconductor, have shown that its IC can reduce power consumption on Voice over Internet Protocol (VoIP) applications by as much as 50% (Fig. 1). The tests, performed on a dual 10/100 Ethernet VoIP desktop phone, recorded that power consumption during a telephone call was less than 800mW.

Unquestionably, VoIP is emerging as the preferred telephony option for businesses, due to its ability to cut operating costs. However, unlike traditional phones, VoIP handsets are powered from mains electricity or via routers/servers through Power over Ethernet (PoE). This makes VoIP power consumption an issue for companies looking to slash electricity costs and demonstrate responsible carbon footprints.

SiTel recently released modified versions of its Enterprise VoIP development kits, featuring hardware and software enhancements that optimise the use of power within VoIP applications.

These modifications have been tested in a dual 10/100 Ethernet VoIP desktop phone dev kit based on the SC14450 VoIP processor. The phone also includes PoE capabilities, an LCD, and keyboard LEDs. Net power consumed after PoE was found to be 569.4 mW in idle mode, and 785.0 mW and 796.5 mW during G.711 and G.722 calls, respectively.

A recent draft version of a European Commission Regulation on ecodesign (implementing Directive 2005/32/EC) proposes limiting the standby power consumption of domestic and office devices to 2W if the device has an information or status display, and 1W otherwise. A future second phase will further tighten these limits to 1W and 0.5W. Phones based on SiTel’s VoIP processors and using these latest enhancements meet these proposed requirements, claims the company.

Staying with the power-saving theme, an1.8-V audio codec with integrated miniDSP developed by Texas Instruments boosts audio performance while extending battery life on portable devices.

This highly integrated audio codec, now in full production with some consumer electronics companies, combines integrated power management and dual miniDSP audio-processing engines to save on design costs. The device has a feature called PowerTune technology that increases playback time—designers are able to tune thedevice for optimum power use in each operating mode.

Designated the TLV320AIC3254, this is the first product from TI to incorporate the highly programmable miniDSP audio-processing engine. The engine allows users to run complex algorithms on the device while freeing MIPS on the primary processor.

By using this new codec and its 192kHz sample rate, customers can add a comprehensive suite of advanced digital-signal-processing capabilities to improve audio performance. These include a 20-band stereo graphic equaliser, multi-band dynamic range compression, custom FIR and IIR filtering, and 3D processing, without needing in-house algorithm expertise or increased investment in resources for code development.

TI will provide all low-level miniDSP programming. Moreover, designers can take advantage of the PurePath Studio development toolset and TI’s library of advanced algorithms to compile, configure, and load their application into the integrated miniDSP engines. This is accomplished via an intuitive, drag-and-drop graphical environment, simplifying design complexity and reducing time-to-market.

TI says this technology gives customers the flexibility to optimise power consumption under any usage model, trading off between ultra-low-power operation and signal-to-noise ratio (SNR) for better audio quality.

For designers concerned with power consumption, they can tune their system to consume as little as 2.4mW in stereo playback when performance is programmed to the 90dB SNR level. Conversely, customers who are seeking to maximise overall performance can achieve 100dB SNR at 5.1mW in stereo playback.

The TLV320AIC3254 includes dual integrated LDOs, which provide additional power-supply rejection and extend device capability to operate single-supply up to 3.6 V. With an integrated stereo headphone amplifier, dual microphone programmable-gain amplifiers, fractional PLL, and analog input multiplexer, the codec simplifies board design and can lower the BOM.

Intersil Corp. recently launched a high-performance, 24V, 2A standard buck PWM regulator. The device offers a simple power solution for a wide range of point-of-load (PoL) applications.

The PWM controller in the ISL8500 regulator (Fig. 2) drives an internal switching N-channel power MOSFET that generates an output voltage from 0.6V to 19V when used with an external Schottky diode. The ISL8500 switches at a fixed frequency of 500kHz and uses simple voltage mode with integrated input-voltage feed-forward control to provide flexibility in component selection, says Intersil.

Output voltage monitoring and power sequencing can be realised using the integrated PGOOD (Power OK) and Enable (EN) features of the ISL8500. The PWM regulator also includes an externally adjustable soft-start time to enable monotonic startup and in-rush current control.

Because it supports an input voltage range of up to 24V, the ISL8500 could very well find its way into 5V point-of-load applications, 12V power supplies, and 24V battery-powered systems.

Two 600V control ICs for energy-efficient dimming fluorescent lighting ballast applications are the latest innovations from International Rectifier (IR) (Fig. 3).

The IRS2530D DIM8 is a linear dimming ballast control IC with a half-bridge driver in an 8-pin form factor. The new device can replace inefficient incandescent bulbs in multilevel and three-way compact-fluorescent-lighting (CFL) applications. The IRS2530D simplifies and shrinks circuit design and delivers a dimming system performance of up to 10% for compact fluorescent lamps as well as linear ballasts.

The IRS2158D 16pin, fluorescent dimming ballast control IC with half-bridge driver is designed for applications requiring dimming performance below 10%. Protection features such as protection from failure of a lamp to strike, filament failures and end-of-life protection are offered making the device well suited for thin lamps including the popular T5 lamp.

Over in Colorado, USA, CADEKA has unveiled two new ADC families, the CDK2307 (12-bit) and CDK2308 (10-bit). The company claims that these ADCs offer the lowest total power dissipation in the market today (Fig. 4). The families currently include both singles and duals that operate at 20, 40, 65, and 80MSPS.

“At 102mW, the dual-channel CDK2307D provides 13-bit performance at 80MSPS sampling rate while consuming over 4x lower power than the closest competitor in its class,” says Olav Lindquist, CADEKA’s sales and marketing director for Europe. “These converters use proprietary pipeline architecture to offer the industry’s best power/performance ratio.”

The CDK2307D offers a noise performance with 72.4dB SNR and 78.2dB spurious-free dynamic range (SFDR) that outperforms most of the competition.