NS ADC08B3000高速ADC方案

NS公司的ADC08B3000是取样速率达到3GSPS的高性能低功耗8位模数转换器(ADC),1.9V和取样3GSPS时的功耗为1.6W,降功耗模式仅为25mW,在整个工作温度内不会丢失码.功率带宽为3GHz,主要应用在测试测量中.本文介绍了ADC08B3000的主要性能和指标,方框图以及采用Xilinx Virtex 4 (XC4VLX15) FPGA和ADC08B3000的参考设计.

ADC08B3000 8-Bit, 3 GSPS, High Performance, Low Power A/D Converter with 4K Buffer

The ADC08B3000 is a single, low power, high performance CMOS analog-to-digital converter that digitizes signals to 8 bits resolution at sample rates up to 3.4 Gigasamples Per Second, (Gsps). Consuming a typical 1.6 Watts at 3 Gsps from a single 1.9 Volt supply, this device is guaranteed to have no missing codes over the full operating temperature range.

The unique folding and interpolating architecture, the fully differential comparator design, the innovative design of the internal sample-and-hold amplifier and the calibration scheme
enable an excellent response of all dynamic parameters up to Nyquist, producing a high 7.1 Effective Number Of Bits, (ENOB), with a 748 MHz input signal and a 3 GHz sample
rate while providing a 10-18 Code Error Rate. A sample rate of 3 Gsps is achieved by interleaving two ADCs, each operating at 1.5 Gsps. Output formatting is offset binary. The
device contains a 4K Capture Buffer with output on two 8-bit Low Voltage CMOS (LVCMOS) output buses at rates up to 200MHz.
The converter typically consumes less than 25 mW in the Power Down Mode and is available in a 128-lead, thermally enhanced exposed pad LQFP and operates over the Industrial (-40°C ≤ TA ≤ +85°C) temperature range.

ADC08B3000主要特性:
■Single +1.9V ±0.1V Operation
■Choice of SDR or DDR output clocking
■Internal selectable 4K Data Buffer
■Serial Interface for Extended Control
■Adjustment of Input Full-Scale Range, Offset and Clock Phase
■Duty Cycle Corrected Sample Clock
■Test Pattern Output Capability
ADC08B3000主要指标:
■Resolution 8 Bits
■Max Conversion Rate 3 Gsps (min)
■Code Error Rate 10-18 (typ)
■ENOB @ 748 MHz Input 7.1 Bits (typ)
■SNR @ 748 MHz 44.9 dB (typ)
■Full Power Bandwidth 3 GHz (typ)
■Power Consumption
—Full Power Capture 1.6 W (typ)
—Power Down Mode 25 mW (typ)

ADC08B3000应用:
■Distance Ranging
■Test and Measurement



图1. ADC08B3000方框图
ADC08B3000RB参考设计
ADC08(B)3000RB: 8-Bit, 3.0 GSPS, A/D Converter with Xilinx Virtex 4 (XC4VLX15) FPGA
The ADC08(B)3000RB Board is designed to allow quick evaluation and design development of National Semiconductor’s ADC083000 and ADC08B3000 8-bit Analog-to-Digital Converters.
These devices are specified for 3.0 GSPS operation. This reference board is designed to
function with National Semiconductor’s WaveVision Software, for fast evaluation.

It requires only 3 connections to get started: a power supply, a USB Interface to PC and an analog signal source.
A 1.5 GHz clock generator is provided on-board and the system also allows for an external clock to be used if alternate sample rates are required.

The ADC connects to a Xilinx Virtex4 FPGA which stores up to 4K of data from each channel before transferring it through the USB interface to the PC.
The ADC08(B)3000RB Evaluation Board comes as a plain board with rubber standoffs and requires no assisted cooling due to its low power consumption. The ADC083000 and
ADC08B3000 devices are configured entirely through software and also allow for changes to easily be made to the FPGA configuration to enable system development.



图2. ADC08B3000RB参考设计外形图



图3. ADC08B3000RB系统方框图