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Protocols,PoE, And The Less-Is-More Objective
Paul Whytock looks at three European developments that give EEs frugal but flexible design opportunities.
Ericsson Power Modules has joined the Power Management Bus (PMBus) Implementers Forum. The company now can contribute to the development of a future, standardized digital power-management platform that it believes will benefit its customers in the short and long terms.
The PMBus open-standard digital power-management protocol facilitates communication with a power converter or other device by defining the transport and physical interface. It was created in October 2004 when Artesyn Technologies, Astec Power, and six major semiconductor manufacturers recognized that the lack of a suitable standard was inhibiting the adoption of an alldigital power-management solution. A total of 19 power sector companies are now on board.
GENEVA, SWITZERLAND STMicroelectronics unveiled its compact class D power-amplifier (PA) chip. Designed for the latest mobile phones and similar products, the TS4962 offers higher audio power output while preserving and extending battery life. It provides 3 W of output power into a 4- loudspeaker when operating from a 5-V power supply. Also, it achieves 88% efficiency.
The TS4962’s supply voltage ranges from 2.4 to 5.5 V. Its quiescent current with no input signal is 2.3 mA typical. Standby current is 10 nA when powered down using its active-low controlline. Pop-and-click reduction circuitry provides low on/off switching noise while allowing the amplifier to start within 5 ms. The gain is set using two external resistors. A fully differential design reduces RF rectification effects and eliminates the need for a bypass capacitor. Output power is 3 W into 4 or 1.75 W into 8 at 10% maximum total harmonic distortion plus noise (THD+N) on a 5-V supply. At 1% maximum THD+N, output power is 2.3 W into 4 on a 5- V supply or 0.75 W on a 3-V supply. Its signal-to-noise ratio is typically 85dB. This small amplifier is available in a lead-free, 1.6-mm2 flip-chip package. It’s supported by a development board, which includes the device pre-mounted onto a flip-chip to dual-inline package adapter for easier handling during evaluation.
