EVAL-AD7873EBZ:  触摸屏数字转换器

The AD7873 is a 12-bit successive approximation ADC with a synchronous serial interface and low on resistance switches for driving touch screens. The AD7873 operates from a single 2.2 V to 5.25 V power supply and features throughput rates greater than 125 kSPS.

The AD7873 features direct battery measurement, temperature measurement, and touch pressure measurement. The AD7873 also has an on-board reference of 2.5 V that can be used for the auxiliary input, battery monitor, and temperature measurement modes. When not in use, the internal reference can be shut down to conserve power. An external reference can also be applied and can be varied from 1 V to VCC and the analog input range is from 0 V to VREF. The device includes a shutdown mode that reduces the current consumption to less than 1 µA.

The AD7873 features on-board switches. This, coupled with low power and high speed operation, makes the device ideal for battery-powered systems such as personal digital assistants with resistive touch screens and other portable equipment. The part is available in a 16-lead, 0.15" quarter size outline package (QSOP), a 16-lead, thin shrink small outline package (TSSOP), and a 16-lead, lead frame chip scale package (LFCSP).

AD7877是一款12位逐次逼近型ADC,具有同步串行接口以及用于驱动触摸屏的低导通电阻开关,采用2.7 V至5.25 V单电源供电(2.2 V也可正常运转),吞吐量为125 kSPS。AD7877可用于两个输入上的电池测量、温度测量和触摸压力测量。

AD7877还具有一个2.5 V片上基准电压源。不使用时,可关断基准电压源以降低功耗。也可以使用外部基准电压,并可在1 V至+VCC范围内变化,模拟输入范围为0 V至VREF。这款器件具有关断模式,此模式下功耗不足1 µA。

片上ADC的相位采集通过STOPACQ引脚来控制,这样可以降低来自LCD的噪声影响。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。该器件还有一个片上DAC,用来控制LCD背光或对比度。AD7877采用转换序列器与定时器,可在从模式或主模式下工作,非常适用于电池供电系统,如带电阻触摸屏的个人数字助理及其它便携式设备。

该器件提供两种封装:32引脚架构芯片级封装(LFCSP)和25引脚晶圆级芯片规模封装(WLCSP)。

Product Highlights
  1. Ratiometric conversion mode available, eliminating errors due to on-board switch resistances.
  2. On-board temperature sensor: −40°C to +85°C.
  3. Battery monitor input.
  4. Touch pressure measurement capability.
  5. Low power consumption of 1.37 mW maximum with the reference off, or 2.41 mW typical with the reference on, at 125 kSPS and VCC at 3.6 V.
  6. Package options include 4 mm × 4 mm LFCSP.
  7. Analog input range from 0 V to VREF.
  8. Versatile serial I/O ports.
  9. 个人数字助理
  10. 智能手持式设备
  11. 触摸屏监控器
  12. POS终端机 、
  13. 医疗设备
  14. 蜂窝电话
  15. 寻呼机
EVAL-AD7873EBZ 特性
AD7873 芯片订购指南
产品型号 产品状态 封装 引脚 温度范围
AD7873ACP 量产 16 ld LFCSP (4x4x.85mm, 2.10mm exposed pad) 16 工业
AD7873ACPZ 量产 16 ld LFCSP (4x4x.85mm, 2.10mm exposed pad) 16 工业
AD7873ACPZ-REEL 量产 16 ld LFCSP (4x4x.85mm, 2.10mm exposed pad) 16 工业
AD7873ACPZ-REEL7 量产 16 ld LFCSP (4x4x.85mm, 2.10mm exposed pad) 16 工业
AD7873ARQZ 量产 16 ld QSOP 16 工业
AD7873ARQZ-REEL 量产 16 ld QSOP 16 工业
AD7873ARQZ-REEL7 量产 16 ld QSOP 16 工业
AD7873ARUZ 量产 16 ld TSSOP 16 工业
AD7873ARUZ-REEL 量产 16 ld TSSOP 16 工业
AD7873ARUZ-REEL7 量产 16 ld TSSOP 16 工业
AD7873BRQZ 量产 16 ld QSOP 16 工业
AD7873BRQZ-REEL 量产 16 ld QSOP 16 工业
AD7873BRQZ-REEL7 量产 16 ld QSOP 16 工业
EVAL-AD7873EBZ 量产 评估板 - 待定
EVAL-AD7873EBZ 应用技术支持与电子电路设计开发资源下载
  1. AD7873 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