AD7822/AD7825/AD7829 均为高速、1/4/8通道、微处理器兼容型、8位模数转换器(ADC),最大吞吐量为2 MSPS。三款器件都内置一个2.5 V(2%容差)片内基准电压源、一个采样保持放大器、一个420 ns的8位半快速型(half-flash)ADC和一个高速并行接口,可采用3 V ±10%和5 V ±10%单电源供电。
AD7822/AD7825/AD7829将转换启动与关断功能结合在一个引脚上,即CONVST引脚,这样便可实现在一次转换结束时自动关断的独特省电模式。当转换结束,即EOC(转换结束)信号变为高电平后,会对CONVST引脚上的逻辑电平进行采样。如果它在该点为逻辑低电平,则ADC关断。AD7822和AD7825还具有单独的关断引脚(参见“工作模式”部分)。利用该并行接口,可方便地与微处理器和DSP进行接口。这些器件仅使用地址解码逻辑,因此很容易实现到微处理器地址空间的映射。利用EOC脉冲,这些ADC可以分别独立工作(参见“并行接口”部分)。
AD7822和AD7825均提供三种封装:20引脚和24引脚、0.3英寸宽、塑料双列直插式封装(PDIP);20引脚和24引脚标准小形集成封装(SOIC);以及20引脚和24引脚超薄紧缩小型封装(TSSOP)。AD7829也提供三种封装:28引脚、0.6英寸宽PDIP;28引脚SOIC;以及28引脚TSSOP。
The AD7822/AD7825/AD7829 are high speed, 1-, 4-, and 8-channel, microprocessor-compatible, 8-bit analog-to-digital converters with a maximum throughput of 2 MSPS. The AD7822/AD7825/AD7829 contain an on-chip reference of 2.5 V (2% tolerance); a track-and-hold amplifier; a 420 ns, 8-bit half-flash ADC; and a high speed parallel interface. The converters can operate from a single 3 V ± 10% and 5 V ± 10% supply.
The AD7822/AD7825/AD7829 combine the convert start and power-down functions at one pin, that is, the CONVST pin. This allows a unique automatic power-down at the end of a conversion to be implemented. The logic level on the CONVST pin is sampled after the end of a conversion when an EOC (end of conversion) signal goes high. If it is logic low at that point, the ADC is powered down. The AD7822 and AD7825 also have a separate power-down pin (see the Operating Modes section).
The parallel interface is designed to allow easy interfacing to microprocessors and DSPs. Using only address decoding logic, the parts are easily mapped into the microprocessor address space. The EOC pulse allows the ADCs to be used in a stand-alone manner (see the Parallel Interface section.)The AD7822 and AD7825 are available in 20-lead and 24-lead, 0.3" wide, plastic dual in-line packages (PDIP); 20-lead and 24-lead standard small outline packages (SOIC); and 20-lead and 24-lead thin shrink small outline packages (TSSOP). The AD7829 is available in a 28-lead, 0.6" wide PDIP; a 28-lead SOIC; and a 28-lead TSSOP.
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AD7822 应用领域
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AD7822 技术指标
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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 |
---|---|---|---|---|---|---|---|
AD7822BNZ 产品状态: 量产 | 20 ld PDIP | 20 | 工业 | Tube, 18 | $ 4.54 | $ 3.55 | 是 |
AD7822BR 产品状态: 量产 | 20 ld SOIC - Wide | 20 | 工业 | Tube, 37 | $ 4.84 | $ 3.79 | 否 |
AD7822BR-REEL 产品状态: 量产 | 20 ld SOIC - Wide | 20 | 工业 | Reel, 1000 | - | $ 3.79 | 否 |
AD7822BRU 产品状态: 量产 | 20 ld TSSOP | 20 | 工业 | Tube, 75 | $ 4.84 | $ 3.79 | 否 |
AD7822BRU-REEL 产品状态: 量产 | 20 ld TSSOP | 20 | 工业 | Reel, 2500 | - | $ 3.79 | 否 |
AD7822BRU-REEL7 产品状态: 量产 | 20 ld TSSOP | 20 | 工业 | Reel, 1000 | - | $ 3.79 | 否 |
AD7822BRUZ 产品状态: 量产 | 20 ld TSSOP | 20 | 工业 | Tube, 75 | $ 4.41 | $ 3.45 | 是 |
AD7822BRUZ-REEL 产品状态: 量产 | 20 ld TSSOP | 20 | 工业 | Reel, 2500 | - | $ 3.45 | 是 |
AD7822BRZ 产品状态: 量产 | SOIC 300 MIL | 20 | 工业 | Tube, 37 | $ 4.41 | $ 3.45 | 是 |
AD7822BRZ-REEL 产品状态: 量产 | 20 ld SOIC - Wide | 20 | 工业 | Reel, 1000 | - | $ 3.45 | 是 |
AD7822BRZ-REEL7 产品状态: 量产 | 20 ld SOIC - Wide | 20 | 工业 | Reel, 400 | - | $ 3.45 | 是 |