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AD7821: 高速、uP兼容型、CMOS、8位采样ADC

AD7821 功能框图AD7821是一款高速、8位采样模数转换器(ADC),性能优于颇受欢迎的AD7820。该器件提供660 ns转换时间(AD7820为1.36 us)及100 kHz信号带宽(AD7820为6.4 kHz)。采样点的界定更精确,在RD的WR下降沿上。该器件具有VSS引脚(引脚19),可采用±5 V电源供电,支持双极性输入信号。也可以采用单极性输入,此时VSS引脚可接地,并且AD7821与AD7820一样,采用+5 V单电源供电。AD7821内置采样保持功能,能够将最大100 kHz带宽的满量程信号数字化。它还采用半快速型(half-flash)转换技术,从而无需为ADC提供CLK信号。AD7821采用标准微处理器控制信号(CS、RD、WR、RDY、INT)和锁存三态数据输出设计,能够与高速数据总线进行接口。它还提供溢出输出(OFL),用于级联器件以提供更高的分辨率。AD7821采用线性兼容CMOS (LC2MOS)制造,这是一种将精密的双极性电路与低功耗CMOS逻辑相结合的先进混合工艺技术。该器件的功耗很低,为50 mW。

The AD7821 is a high-speed, 8-bit, sampling, analog-to-digital converter that offers improved performance over the popular AD7820. It offers a conversion time of 660 ns (vs. 1.36 us for the AD7820) and 100 kHz signal bandwidth (vs. 6.4 kHz). The sampling instant is better defined and occurs on the falling edge of WR of RD. The provision for a VSS pin (Pin 19) allows the part to operate from ±5 V supplies and to digitize bipolar input signals. Alternatively, for unipolar inputs, the VSS pin can be grounded and the AD7821 will operate from a single +5 V supply, like the AD7820.The AD7821 has a built-in track-and-hold function capable of digitizing full-scale signals up to 100 kHz max. It also uses a half-flash conversion technique that eliminates the need to generate a CLK signal for the ADC.The AD7821 is designed with standard microprocessor control signals (CS, RD, WR, RDY, INT) and latched, three-state data outputs capable of interfacing to high-speed data buses. An overflow output (OFL) is also provided for cascading devices to achieve higher resolution.The AD7821 is fabricated in Linear-Compatible CMOS (LC2MOS), an advanced, mixed technology process combining precision bipolar circuits with low-power CMOS logic. The part features a low power dissipation of 50 mW.

AD7821 特点
  • 快速转换时间:660 ns(最大值)
  • 100 kHz采样保持功能
  • 采样率:1 MHz
  • 双极性和单极性输入范围
  • 比率基准电压输入
  • 无外部时钟
  • 可在扩展温度范围内工作
  • 超小型20引脚DIP、SOIC和表面贴装封装
AD7821 技术指标
  • Resolution (Bits): 8bit
  • # Chan: 1
  • Sample Rate: 1MSPS
  • Interface: Par
  • Analog Input Type: SE-Bip,SE-Uni
  • Ain Range: Bip (Vref),Uni (Vref)
  • ADC Architecture: Pipelined
  • Pkg Type: DIP,LCC,SOIC
AD7821 芯片订购指南
产品型号 封装 引脚 温度范围 包装和数量 报价*(100-499) 报价*1000 pcs RoHS
5962-89518012A 产品状态: 量产 LCC:CER LEADLESS CHIP CARR 20 军用 Tube, 54 $ 139.04 $ 125.70
5962-8951801RA 产品状态: 量产 CERDIP GLASS SEAL 20 军用 Tube, 18 $ 71.47 $ 64.62
AD7821BCHIPS 产品状态: 联络ADI CHIPS OR DIE - 商业 Tray, 100 $ 10.47 $ 10.47
AD7821BQ 产品状态: 量产 CERDIP GLASS SEAL 20 工业 Tube, 18 $ 19.98 $ 19.98
AD7821KN 产品状态: 量产 20 ld PDIP 20 商业 Tube, 18 $ 12.46 $ 10.58
AD7821KNZ 产品状态: 量产 20 ld PDIP 20 商业 Tube, 18 $ 10.79 $ 9.16
AD7821KPZ 产品状态: 量产 20 ld PLCC 20 商业 Tube, 49 $ 12.60 $ 10.16
AD7821KPZ-REEL 产品状态: 量产 20 ld PLCC 20 商业 Reel, 1000 - $ 10.16
AD7821KRZ 产品状态: 量产 20 ld SOIC - Wide 20 商业 Tube, 37 $ 12.00 $ 9.68
AD7821KRZ-REEL 产品状态: 量产 20 ld SOIC - Wide 20 商业 Reel, 1000 - $ 9.68
AD7821TCHIPS 产品状态: 联络ADI CHIPS OR DIE - 商业 Tray, 100 $ 31.63 $ 31.63
AD7821TQ 产品状态: 量产 CERDIP GLASS SEAL 20 军用 Tube, 18 $ 49.90 $ 49.90
AD7821 应用技术支持与电子电路设计开发资源下载
  1. AD7821 数据手册DataSheet下载 .PDF
  2. Analog Devices, Inc.ADI 美国模拟器件公司产品订购手册 .PDF
  3. ADC模数转换器选型指南 . PDF