AD8803AR: 8通道、8位TrimDAC,具有电源关断和中量程预设功能
The AD8801/AD8803 provides eight digitally controlled dc voltage outputs. This potentiometer divider TrimDAC® allows replacement of the mechanical trimmer function in new designs. The AD8801/AD8803 is ideal for dc voltage adjustment applications.
Easily programmed by serial interfaced microcontroller ports, the AD8801 with its midscale preset is ideal for potentiometer replacement where adjustments start at a nominal value. Applications such as gain control of video amplifiers, voltage controlled frequencies and bandwidths in video equipment, geometric correction and automatic adjustment in CRT computer graphic displays are a few of the many applications ideally suited for these parts. The AD8803 provides independent control of both the top and bottom end of the potentiometer divider allowing a separate zero-scale voltage setting determined by the VREFL pin. This is helpful for maximizing the resolution of devices with a limited allowable voltage control range.
Internally the AD8801/AD8803 contain eight voltage output digital-to-analog converters, sharing a common reference voltage input.
Each DAC has its own DAC register that holds its output state. These DAC registers are updated from an internal serial-to-parallel shift register that is loaded from a standard three-wire serial input digital interface. Eleven data bits make up the data word clocked into the serial input register. This data word is decoded where the first 3 bits determine the address of the DAC register to be loaded with the last 8 bits of data. The AD8801/AD8803 consumes only 5 mA from 5 V power supplies. In addition, in shutdown mode reference input current consumption is also reduced to 5 µA while saving the DAC latch settings for use after return to normal operation.
The AD8801/AD8803 is available in 16-pin plastic DIP and the 1.5 mm height SO-16 surface mount packages.
AD8801/AD8803均为电位计分压器TrimDAC®数模转换器,提供八路数字控制直流电压输出,可以在新设计中取代机械式调整器功能,非常适合直流电压调节应用。
AD8801具有中量程预设功能,可以通过串行接口的微控制器端口轻松编程,非常适合取代从标称值开始调节的电位计。这些器件是众多应用的理想选择,例如视频放大器的增益控制,视频设备中的电压控制频率和带宽,CRT计算机图形显示器中的几何校正和自动调节等等。AD8803能够独立控制电位计分压器的顶端和低端,允许通过VREFL引脚单独确定零电平电压设置。对于容许电压控制范围有限的器件,这一功能有助于其获得最大分辨率。
AD8801/AD8803均内置8个电压输出数模转换器(DAC),这些DAC共用一个基准电压输入。
每个DAC均有各自的DAC寄存器以保持其输出状态,这些DAC寄存器由一个内部串行至并行移位寄存器更新,该移位寄存器从一个标准三线式串行输入数字接口加载数据。由11个数据位构成的数据字同步传输至串行输入寄存器,该数据字经过解码,前3位可确定需要载入后8位数据的DAC寄存器地址。采用5 V电源供电时,AD8801/AD8803的功耗仅为5 mA。此外,在关断模式下,基准电压输入功耗也降至5 µA,仅保留DAC锁存器设置,供返回正常工作模式后使用。
AD8801/AD8803提供16引脚塑封DIP和1.5 mm、SO-16表贴两种封装。
AD8803AR 特点
- Low Cost
- Replaces Eight Potentiometers
- Eight Individually Programmable Outputs
- Three-Wire Serial Input
- Power Shutdown = µW
Including IDD an IREF - Midscale Preset, AD8801
- Separate VREFLRange Setting, AD8803
- +3 to +5 Single Supply Operation
- 低成本
- 可取代8个电位计
- 8路单独可编程输出
- 三线式串行输入
- 关断模式：≤ µW（包括IDD和IREF）
- 中量程预设功能(AD8801)
- 单独的VREFL范围设置(AD8803)
- +3 V至+5 V单电源供电
AD8803AR 功能框图
| 产品型号 | 产品状态 | 封装 | 引脚 | 温度范围 |
|---|---|---|---|---|
| AD8803AR | 量产 | 16 ld SOIC | 16 | 工业 |
| AD8803ARZ | 量产 | 16 ld SOIC | 16 | 工业 |
| AD8803ARZ-REEL | 量产 | 16 ld SOIC | 16 | 工业 |
