AD7889: 用于触摸屏的低电压控制器
AD7879/AD7889是12位逐次逼近型模数转换器(SAR ADC)，具有同步串行接口以及用于驱动4线电阻触摸屏的低导通电阻开关。AD7879/AD7889工作电源电压极低，采用1.6 V至3.6 V单电源供电, 吞吐速率为105 kSPS。这些器件具有关断模式，此模式下功耗不足6 µA。为了降低来自LCD以及其它源的噪声，AD7879/AD7889内置预处理模块。预处理功能包括中值滤波器及均值滤波器。这两个滤波器的结合提供了更稳定的解决方案，能滤除信号中的杂散噪声，而只保留有用的数据。两个滤波器的尺寸都可以设置。其它用户可编程转换控制包括可变采集时间及第一转换延迟。每次转换可利用多达16个均值。AD7879/AD7889采用自动转换序列器与定时器，可以在从模式或独立（主）模式下工作。AD7879/AD7889拥有可编程引脚，可以用作到ADC的辅助输入、电池监控器或通用接口。此外，可编程中断输出有三种工作模式：作为新数据可用时的通用中断(DAVINT)，或作为屏幕被触摸时的触点中断 (PENIRQ)。AD7879/AD7889可提供温度与触摸压力测量。AD7879提供12引脚、1.6 mm × 2 mm WLCSP和16引脚、4 mm × 4 mm LFCSP两种封装。AD7889采用背面镀膜WLCSP封装。两款器件均支持SPI接口(AD7879/AD7889)或I2C®接口(AD7879-1/AD7889-1)。
The AD7879/AD7889 are 12-bit successive approximation analog-to-digital converters (SAR ADCs) with a synchronous serial interface and low on-resistance switches for driving 4-wire resistive touch screens. The AD7879/AD7889 work with a very low power supply–a single 1.6 V to 3.6 V supply–and feature throughput rates of 105 kSPS. The devices include a shutdown mode that reduces current consumption to less than 6 μA.To reduce the effects of noise from LCDs and other sources, the AD7879/AD7889 contain a preprocessing block. The prepro-cessing function consists of a median filter and an averaging filter. The combination of these two filters provides a more robust solution, discarding the spurious noise in the signal and keeping only the data of interest. The size of both filters is programmable. Other user-programmable conversion controls include variable acquisition time and first conversion delay; up to 16 averages can be taken per conversion. The AD7879/AD7889 can run in slave mode or standalone (master) mode, using an automatic conversion sequencer and timer.The AD7879/AD7889 have a programmable pin that can operate as an auxiliary input to the ADC, as a battery monitor, or as a GPIO. In addition, a programmable interrupt output can operate in three modes: as a general-purpose interrupt to signal when new data is available (DAV), as an interrupt to indicate when limits are exceeded (INT), or as a pen-down interrupt when the screen is touched (PENIRQ). The AD7879/AD7889 offer temp-erature measurement and touch-pressure measurement.The AD7879 is available in a 12-ball, 1.6 mm × 2 mm WLCSP and in a 16-lead, 4 mm × 4 mm LFCSP. The AD7889 is available in a backside-coated version of the WLCSP. Both parts support an SPI interface (AD7879/AD7889) or an I²C® interface (AD7879-1/AD7889-1).
AD7889 特性
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AD7889 技术指标
AD7889 应用领域
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AD7889 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 |
|---|---|---|---|---|---|---|
| AD7889-1ACBZ-500R7 产品状态: 量产 | 12 Ball WLCSP (1.61x2.01) | 12 | 工业 | Reel, 500 | - | $ 1.69 |
| AD7889-1ACBZ-RL 产品状态: 量产 | 12 Ball WLCSP (1.61x2.01) | 12 | 工业 | Reel, 10000 | - | $ 1.69 |
| AD7889-1ACBZ-RL7 产品状态: 量产 | 12 Ball WLCSP (1.61x2.01) | 12 | 工业 | Reel, 3000 | - | $ 1.69 |
| AD7889ACBZ-500R7 产品状态: 量产 | 12 Ball WLCSP (1.61x2.01) | 12 | 工业 | Reel, 500 | - | $ 1.69 |
| AD7889ACBZ-RL 产品状态: 量产 | 12 Ball WLCSP (1.61x2.01) | 12 | 工业 | Reel, 10000 | - | $ 1.69 |
