wirelessZONE Products for the week of August 17, 2009

National Semiconductor Says…

ADC16DV160: First Dual 16-bit, 160-Msample/s Pipeline ADC
Innovative Low-power Architecture Enables Industry‘s Best Dynamic Performance for Multi-Carrier, Multi-Standard Basestations

National Semiconductor Corp. introduced the industry’s first dual-channel 16-bit, 160 mega-samples per second (MSPS) pipeline analog-to-digital converter (ADC). With two high-speed channels, the ADC16DV160 offers system designers the world’s best dynamic performance and smallest footprint (10 mm by 10 mm) to reduce system size, design complexity and development costs. The ADC16DV160 is targeted at multi-carrier, multi-standard GSM/EDGE, WCDMA, LTE and WiMAX wireless basestations.

The ADC16DV160 consumes less than half the power per ADC channel (650 mW) compared to competing single-channel 16-bit 160-MSPS pipeline ADCs, while offering the largest input-bandwidth (1.4 GHz) and the industry’s best dynamic performance at high input frequencies. The ADC16DV160 delivers 91.2 decibels full scale (dBFS) spurious-free dynamic range (SFDR), 76.3 dBFS signal-to-noise ratio (SNR) and 97.3 dBFS higher-order harmonic distortion at 197 MHz input frequency.

The ADC16DV160’s industry-leading dynamic performance enables increased basestation capacity and coverage, allowing service providers to reach more customers and deliver a higher quality of service. The ADC16DV160’s energy efficiency reduces system power dissipation and relaxes basestation power management circuitry requirements. This increases overall system reliability and reduces system cooling requirements.


EN-Genius Says…

I am getting really fed up with vendors in my analog space who are projecting production dates three to six months after their product announcements in order to thwart other vendors who are actually delivering product. Analog Devices, in its new-generation form, has now been doing this for the last few years and now National Semiconductor is stepping into the same space with a product fighting the undelivered AD9262 (with only 10 MHz full-power bandwidth!) with the now-promised ADC16DV160, both proposing to be 16 bit 160 Msample/s ADCs with power per channel of the order of 500 mW. The major difference between the parts is probably the architecture, National favoring pipeline and ADI favoring delta-sigma.

The National part – with a questionable SNR specification – is, after all, only two years behind Linear’s LTC2209 (single channel) and one year behind TI’s single channel ADS5484 and ADS5485. 

As we have written on these pages many times, it is impossible to adequately compare data sheet to data sheet specifications with these kinds of parts. Like the ADI part the power consumption numbers of the ADC16DV160 are impressive compared to TI and LTC but in a basestation environment it is not really the receive channel that is of concern when it comes to power. The part is, presumably, a derivative of the single channel 130 Msample/s ADC16V130.

The National part offers an impressive 1.4 GHz full power bandwidth and crosstalk is quoted at 103 dBFS (a positive number, because?) with a 32.5 MHz input signal on the tested channel and 102 MHz on the other. Probably the most critical specification for dual channel operation with large signal bandwidths is the difference in latency between channels: that is not given in the data sheet. The input S11 is also a potential design hazard with dominant capacitive loading up to 500 MHz, especially because you will probably want to add some shunt capacitance to absorb sampling switch charges.

The ADC16DV160 uses dual 1.8 V and 3.0 V supplies and has LVDS outputs. The input range can be selected to be 2.4 V, 2.0 V, 1.5 V, or 1.0 V, all peak-to-peak.

National does not have a large number of support products for this ADC although their dual digital VGA, the LMH6517, is an ideal driver for IF applications. The part will, however, be subject to export controls – a major reason Linear put the LTC2208 (and, presumably to come, the LTC2209) in a µModule with a complete signal chain as the LTM9001. 

This ADC will sell moderately well, if only to customers who would prefer to buy from National, into multi-standard basestation designs. Its street price will be closer to $85 than that quoted here.

The ADC16DV160 is sampling in thermally-enhanced LLP68. Production is slated for late in Q4 of 2009 when it will be priced at $140 in 1000-piece lots.

Data Sheet