January 29, 2008 -- National Semiconductor Corp. has announced the availability of the 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, 50MSPS (mega-samples per second) ADC that offers an alias-free sample bandwidth up to 25MHz, while consuming 30% less power (350mW) than competing pipeline devices.

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 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

Key technical features

The ADC12EU050 12-bit, ultra-low-power, octal CTSD ADC offers an alias-free sample bandwidth up to 25MHz and a conversion rate of 40MSPS to 50MSPS. The device features 68dB of signal-to-noise and distortion (SINAD) and a signal-to-noise ratio (SNR) of 70dB full scale (dBFS). Operating from a 1.2-V supply, it consumes 44mW per channel at 50MSPS for a total power consumption of only 350mW. The ADC12EU050 reduces interconnection complexity by using programmable serialized outputs, which offer industry-standard low-voltage differential signaling (LVDS) and scalable low-voltage signaling (SLVS) modes. The ADC12EU050 operates over the -40°C to 85°C temperature range and is supplied in a 10x10-mm, 68-pin LLP package.

Pricing and Availability