HONG KONG: National Semiconductor Corp.  announced the availability of the industry's first high-speed, continuous-time sigma-delta (CTSD) analog-to-digital converter (ADC).

The ADC12EU050, a member of National's PowerWise energy-efficient family, is an 8-channel, 12-bit, 50 mega-samples per second (MSPS) ADC that offers an alias-free sample bandwidth up to 25 MHz, while consuming only half the power (350 mW) of competing pipeline devices. This low-power breakthrough enables manufacturers to extend battery life and reduce heat in portable medical ultrasound and industrial imaging equipment.

CTSD technology has been the subject of university and industry research for more than 15 years. With the introduction of the ADC12EU050, National is the first manufacturer to successfully transition CTSD technology from the research lab to the production line.

National plans to expand its CTSD ADC product offering for imaging, communications, and test and measurement applications that require high dynamic performance at extremely low power. The continuous-time architecture greatly simplifies system design as it allows the integration of other signal-path functions, such as signal conditioning, while incorporating anti-aliasing filtering into the ADC.

The ADC12EU050's innovative CTSD architecture offers many advantages compared to traditional pipeline architectures:

* Lower power dissipation;
* Integrated low-pass, brickwall anti-aliasing filter that blocks out-of-band signals from aliasing down in-band;
* Easy-to-drive, purely resistive input stage that does not require a sample-and-hold amplifier;
* Integrated phase-locked loop (PLL) and voltage-controlled oscillator (VCO) that performs clock conditioning, enabling system designers to use inexpensive clock sources;
* On-chip instant-overload recovery (IOR) circuitry that recovers from saturation within one clock cycle, if the input exceeds pre-determined limits.