AD7247AAR: 双通道12位DACPORT,采用并行加载结构
The AD7237A/AD7247A is an enhanced version of the industry standard AD7237/AD7247. Improvements include operation from 12 V to 15 V supplies, faster interface times and better reference variations with VDD . Additional features include faster settling times.
The AD7237A/AD7247A is a complete, dual, 12-bit, voltage output digital-to-analog converter with output amplifiers and Zener voltage reference on a monolithic CMOS chip. No external user trims are required to achieve full specified performance.
Both parts are microprocessor compatible, with high speed data latches and interface logic. The AD7247A accepts 12-bit parallel data which is loaded into the respective DAC latch using the WR input and a separate Chip Select input for each DAC. The AD7237A has a double buffered interface structure and an 8-bit wide data bus with data loaded to the respective input latch in two write operations. An asynchronous LDAC signal on the AD7237A updates the DAC latches and analog outputs.
A REF OUT/REF IN function is provided which allows either the on-chip 5 V reference or an external reference to be used as a reference voltage for the part. For single supply operation, two output ranges of 0 V to +5 V and 0 V to +10 V are available, while these two ranges plus an additional ±5 V range are available with dual supplies. The output amplifiers are capable of developing +10 V across a 2 k(ohm) load to GND.
The AD7237A/AD7247A is fabricated in Linear Compatible CMOS (LC2 MOS), an advanced, mixed technology process that combines precision bipolar circuits with low power CMOS logic. Both parts are available in a 24-pin, 0.3" wide plastic and hermetic dual-in-line package (DIP) and are also packaged in a 24-lead small outline (SOIC) package。
AD7237A/AD7247A分别是业界标准产品AD7237/AD7247的增强型版本,具体改进包括：采用12 V至15 V电源供电、接口时间更快、基准电压随VDD的波动性能更佳,以及建立时间更快。
AD7237A/AD7247A均为完整的双通道、12位、电压输出数模转换器,在CMOS单芯片上集成了输出放大器和齐纳基准电压源,无需用户进行外部调整便可实现全部额定性能。
两款器件均与微处理器兼容,并配有高速数据锁存和接口逻辑。AD7247A接受12位并行数据,数据通过WR输入和各DAC单独的芯片选择(Chip Select)输入载入相应的DAC锁存器。AD7237A具有一个双缓冲接口结构和一个8位宽数据总线,数据通过两次写操作载入相应的输入锁存器。AD7237A上的异步LDAC信号可更新DAC锁存和模拟输出。
这些器件具有REF OUT/REF IN（基准电压源：外部/内部）功能,基准电压既可以从5 V片内基准电压源获得,也可以从外部基准电压源获得。采用单电源供电时,可以提供0 V至+5 V和0 V至+10 V两种输出范围；采用双电源供电时,除以上两种输出范围外,还额外提供±5 V输出范围。输出放大器能够在一个2 kΩ负载上产生对地(GND) +10 V电压。
AD7237A/AD7247A采用线性兼容CMOS (LC2 MOS工艺制造,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。两款器件均提供两种封装：0.3英寸宽、24引脚塑料密封双列直插式封装(DIP)和24引脚小形集成封装(SOIC)。
AD7247AAR 特点
- Complete Dual 12-Bit DAC Comprising Two 12-Bit CMOS DACs On-Chip Voltage Reference Output Amplifiers Reference Buffer Amplifiers
- Parallel Loading Structure: AD7247
- (8 + 4) Loading Structure: AD7237
- Single or Dual Supply Operation
- Low Power - 165 mW typ in Single Supply
- 完整的双通道12位DAC,内置：
两个12位CMOS DAC
片内基准电压源
输出放大器
基准电压缓冲放大器 - 并行加载结构：AD7247A
- AD7237/AD7247改进型：
采用12 V至15 V电源供电
更快的接口（数据设置时间典型值为30 ns） - (8+4)加载结构：AD7237A
- 单电源或双电源供电
- 低功耗：165 mW（典型值,单电源）
AD7247AAR 功能框图
| 产品型号 | 产品状态 | 封装 | 引脚 | 温度范围 |
|---|---|---|---|---|
| AD7247AACHIPS | 量产 | CHIPS OR DIE | - | 工业 |
| AD7247AAN | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7247AANZ | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7247AAR | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247AAR-REEL | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247AAR-REEL7 | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247AARZ | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247AARZ-REEL | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247AARZ-REEL7 | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247ABN | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7247ABNZ | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7247ABR | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247ABR-REEL | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247ABRZ | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247ABRZ-REEL | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247AQ | 量产 | CERDIP GLASS SEAL | 24 | 工业 |
| AD7247ATQ | 量产 | CERDIP GLASS SEAL | 24 | 军用 |
| AD7247BQ | 量产 | CERDIP GLASS SEAL | 24 | 工业 |
| AD7247JN | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7247JNZ | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7247JR | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247JRZ | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247KN | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7247KNZ | 量产 | 24 ld PDIP | 24 | 工业 |
| AD7247KR | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247KRZ | 量产 | 24 ld SOIC - Wide | 24 | 工业 |
| AD7247SCHIPS | 量产 | CHIPS OR DIE | - | 军用 |
