Maxim公司的MAX11905是20位1.6Msps单路全差分SAR ADC,具有极好静态和动态性能,SNR为98.3dB,THD为-123dB,INL为6 LSB,不丢失码20位分辨率.主要用在测试和测量,自动化测试设备(ATE),医疗仪表,过程控制和工业自动化,数据采集系统,通信设备和以电池为能源的设备.本文介绍了MAX11905优势和主要特性,框图,应用框图以及MAX11905差分评估板主要特性,电路图,材料清单和PCB设计图.

The MAX11905 is a 20-bit, 1.6Msps, single-channel, fully differential SAR ADC with internal reference buffers. The MAX11905 provides excellent static and dynamic perfor­mance with best-in-class power consumption that directly scales with throughput. The device has a unipolar differ­ential ±VREF input range. Supplies include a 3.3V supply for the reference buffers, a 1.8V analog supply, a 1.8V digital supply, and a 1.5V to 3.6V digital interface supply.

This ADC achieves 98.3dB SNR and -123dB THD, guar­antees 20-bit resolution with no-missing codes and 6 LSB INL (max).The MAX11905 communicates data using a SPI-compatible serial interface. The MAX11905 is offered in a 20-pin, 4mm x 4mm, TQFN package and is specified over the -40 ℃ to +85 ℃ operating temperature range.

MAX11905优势和主要特性:

High DC/AC Accuracy Provides Better Measurement Quality 20-Bit Resolution with No Missing Codes

±6 LSB INL and ±1 LSB DNL Maximum at 20 Bits

98.3dB SNR and 98.1dB SINAD at fIN= 10kHz

-123dB THD at fIN= 10kHz

High Sampling Rate SAR Architecture Enables Fast Settling and Acquisition 1.6Msps Throughput with No Pipeline Delay

Integration Simplifies Design Integrated Reference Buffers, VREF = 2.5V to 3.6V

±VREF Unipolar Differential Analog Input Range

Scalable Ultra-Low Power Supply Reduces Power Consumption 9mW at 1.6Msps

Flexible Low-Voltage Supplies Save Cost 1.8V Analog and Digital Core Supply

1.5V to 3.6V Digital Interface Supply

3.3V REFVDD Reference Buffer Supply

Flexible, Industry-Standard Serial Interface and Small Package Reduce Size SPI-/QSPI™-/MICROWIRE®/DSP-Compatible

20-Pin, 4mm x 4mm, TQFN Package

MAX11905应用:

Test and Measurement

Automatic Test Equipment

Medical Instrumentation

Process Control and Industrial Automation

Data Acquisition Systems

Telecommunications

Battery-Powered Equipment

图1.MAX11905框图

图2.MAX11905应用框图

MAX11905差分评估板

The MAX11905 differential evaluation kit (EV kit) demonstratesthe MAX11905, 20-bit, 1.6Msps, single-channel,fully differential SAR ADC with internal reference buffers.

The EV kit uses the MAX44205, a low-noise fully differentialoperational amplifier. The EV kit includes a graphicaluser interface (GUI) that provides communication fromAvnet’s ZedBoard™ development board for the XilinxZynq®-7000 SoC. The ZedBoard, not included with theEV kit, must be purchased through Avnet, Inc.

The ZedBoard communicates with the PC through anEthernet cable using Windows XP®-, Windows Vista®-,Windows® 7-, or Windows 8/8.1-compatible software.

MAX11905差分评估板主要特性:

●● Peripheral Module and FMC Connector for Interface

●● 75MHz SPI Clock Capability through FMC Connector

●● 37.5MHz SPI Clock Capability through PeripheralModule Connector

●● Sync In and Sync Out for Coherent Sampling

●● On-Board Input Buffer (MAX44205)

●● On-Board +3.0V Reference Voltage (MAX6126)

●● Windows XP-, Windows Vista-, Windows 7-, andWindows 8/8.1-Compatible Software

图3.MAX11905差分评估板系统框图

图4.MAX11905差分评估板电路图(1)

图5.MAX11905差分评估板电路图(2)

图6.MAX11905差分评估板电路图(3)

MAX11905差分评估板材料清单:

图7.MAX11905差分评估板PCB设计图(1)

图8.MAX11905差分评估板PCB设计图(2)

图9.MAX11905差分评估板PCB设计图(3)

图10.MAX11905差分评估板PCB设计图(4)

图11.MAX11905差分评估板PCB设计图(5)

图12.MAX11905差分评估板PCB设计图(6)

图13.MAX11905差分评估板PCB设计图(7)

图14.MAX11905差分评估板PCB设计图(8)

MAXIM (模拟信号和混合信号半导体公司)

MAXIM是美信公司(Maxim Integrated Products)的英文缩写，全球最好的模拟信号和混合信号半导体公司。同时MAXIM也是一款时尚潮流杂志的名字，maxim内容涵盖了音乐、体育、电视、电影、潮流名人等。也是比较温和的男性杂志，以更多的消遣内容为主。

2001年，Maxim并购了著名的Dallas Semiconductor。是全球最好的模拟信号和混合信号半导体公司.

它们的使命是不断创造高品质的模拟工程解决方案，在世界范围内为基于微处理器的电子产品客户提供增值服务。它们通过努力达到它们的成本与业绩Maxim Integrated Products成立于1983年，总部位于美国加利福尼亚的Sunnyvale，公司拥有9300多名员工，是世界范围内模拟和混合信号集成产品的设计、开发与生产领域的领导者之一。通过对温度、压力、声音等现实世界的各种信号进行检测、放大，并将其转换成计算机处理所需要的数字信号, Maxim的电路把现实世界与数字世界“连接”在一起。

目标、缩短新品上市时间并不断提高它们的生产能力，坚持不懈地为它们的客户和公司股权持有者提供最好的服务。

任何电子产品的核心都是一个数字核，它与人类、真实的物理世界、供电电源及其它数字系统相关联。Maxim是全球模拟、混合信号、高频及数字电路设计、研发、制造的领导者，所提供的产品能够实现上述数字内核与周边系统的连接。它们在世界范围内拥有大约35,000个大型客户。

它们的半导体产品是连接数字处理器与物理世界的桥梁。