CapTouch™控制器设计用于电容式传感器,以实现按钮、滚动条和滚轮等功能。这种传感器只需一层PCB板,为超薄型应用创造了可能。AD7147是一种配备片内环境校准功能的集成式CDC。该CDC有13个输入通道,通过一个开关矩阵与一个16位、250 kHz sigma-delta （Σ-Δ） 转换器相连。该CDC能够感知外部传感器的电容变化,并借助此信息来记录传感器xx事件。通过对寄存器进行编程,用户可xx控制CDC设置。高分辨率传感器只要求在主机处理器上运行较少的软件。AD7147设计用于单电极电容式传感器（接地传感器）。配有一个有源屏蔽输入,以尽可能降低传感器中的噪声影响。
AD7147配有片内校准逻辑,用以补偿周围环境发生的变化。只要传感器闲置时,校准序列就自动按连续间隔执行,由此避免发生因环境变化导致的外部传感器误触或触摸未记录事件。AD7147采用SPI兼容型串行接口,AD7147-1则采用I²C兼容型串行接口。两者都有中断输出和GPIO。还有一个独立于VCC的VDRIVE针脚,用于设定串行接口的电平。AD7147采用24引脚4 mm × 4 mm LFCSP封装,工作电压为2.6 V到3.6 V。低功耗模式下,13个传感器的工作功耗通常为26 µA。
The AD7147 is designed for use with capacitance sensors implementing functions such as buttons, scroll bars, and wheels. The sensors need only one PCB layer, enabling ultra thin applications.The AD7147 is an integrated CDC with on-chip environmental calibration. The CDC has 13 inputs channeled through a switch matrix to a 16-bit, 250 kHz sigma-delta (Σ-Δ) converter. The CDC is capable of sensing changes in the capacitance of the external sensors and uses this information to register a sensor activation. By programming the registers, the user has full control over the CDC setup.High resolution sensors require minor software to run on the host processor.
The AD7147 is designed for single-electrode capacitance sensors (grounded sensors). There is an active shield output to minimize noise pickup in the sensor.
The AD7147 has on-chip calibration logic to compensate for changes in the ambient environment. The calibration sequence is performed automatically and at continuous intervals as long as the sensors are not touched. This ensures that there are no false or nonregistering touches on the external sensors due to a changing environment.The AD7147 has an SPI-compatible serial interface, and the AD7147-1 has an I²C®-compatible serial interface. Both parts have an interrupt output, as well as a GPIO. There is a VDRIVE pin to set the voltage level for the serial interface independent of VCC.
The AD7147 is available in a 24-lead, 4 mm × 4 mm LFCSP and operates from a 2.6 V to 3.6 V supply. The operating current consumption in low power mode is typically 26 μA for 13 sensors.
应用
- 手机
- 个人音乐播放器和多媒体播放器
- 智能型手持设备
- 电视、A/V和遥控
- 游戏机
- 数码相机
Applications
- Cell phones
- Personal music and multimedia players
- Smart handheld devices
- Television, A/V, and remote controls
- Gaming consoles
- Digital still cameras
EVAL-AD7147-1EBZ 特点
- 可编程的电容-数字转换器（CDC）
参阅数据手册 - 片内自动校准逻辑
参阅数据手册 - 寄存器图可与AD7142兼容
- 用片内RAM存储校准数据
- SPI兼容型（串行外设接口兼容）串行接口（AD7147）
- I²C兼容型串行接口（AD7147-1）
- 串行接口专用独立VDRIVE电平
- 有关更多特性,请参阅数据手册
- Programmable capacitance-to-digital converter (CDC)
Femtofarad resolution
13 capacitance sensor inputs
9 ms update rate, all 13 sensor inputs
No external RC components required
Automatic conversion sequencer - On-chip automatic calibration logic
Automatic compensation for environmental changes
Automatic adaptive threshold and sensitivity levels - Register map is compatible with the AD7142
- On-chip RAM to store calibration data
- SPI-compatible (serial-peripheral-interface-compatible) serial interface (AD7147)
- I²C-compatible serial interface (AD7147-1)
- Separate VDRIVE level for serial interface
- Interrupt output and general-purpose input/output (GPIO)
- 24-lead, 4 mm × 4 mm LFCSP
- 2.6 V to 3.3 V supply voltage
- Low operating current
Full power mode: 1 mA
Low power mode: 21.5 μA
EVAL-AD7147-1EBZ 结构
技术指标
AD7147 选型
