AD7889:  用于触摸屏的低电压控制器

AD7889 功能框图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
  • 4线触摸屏接口
  • 工作电压:1.6 V至3.6 V
  • 中值滤波器与均值滤波器,用于降低噪声
  • 自动转换序列器与定时器
  • 用户可编程的转换参数
  • 辅助模拟输入/电池监控器(0.5 V至5 V)
  • 1个可选的通用接口(GPIO)
  • 中断输出(INT,PENIRQ)
  • 触摸压力测量
  • 触摸唤醒功能
  • 关断模式:6 µA(最大值)
  • 12引脚1.6 mm × 2 mm WLCSP封装
  • 16引脚、4 mm × 4 mm LFCSP封装
AD7889 技术指标
  • Resolution (Bits): 12bit
  • # Chan: 6
  • Sample Rate: 105kSPS
  • Interface: I²C/Ser 2-Wire,Ser,SPI
  • Analog Input Type: SE-Uni
  • Ain Range: Uni Vdd
  • ADC Architecture: SAR
  • Pkg Type: CSP
AD7889 应用领域
  • 个人数字助理
  • 智能型手持设备
  • 触摸屏监控器
  • POS终端机
  • 医疗设备
  • 蜂窝电话
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
AD7889 应用技术支持与电子电路设计开发资源下载
  1. AD7889 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