EVAL-AD7147-1EBZ: CapTouchTM单电极电容式传感器专用可编程控制器

AD7147 CapTouchTM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激活事件。通过对寄存器进行编程,用户可完全控制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I^2C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 uA。

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 I^2C(R)-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.

产品应用领域 Applications

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

产品应用领域 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）
I^2C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)
I^2C-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 功能框图

技术指标

Resolution (Bits)	16bit	Interface	I^2C/Ser 2-Wire,Ser,SPI
T-Put Rate	111SPS	Ain Range	± 8 pF (Delta C)
# Chan	13	SNR (dB)	n/a
Supply V	Single(+3),Single(+3.3)	Pkg Type	CSP
Pwr Diss	3.6mW

AD7147 芯片订购指南

产品型号	产品状态	封装	引脚	温度范围
AD7147ACPZ-1500RL7	Prodn	24 ld LFCSP (4x4mm 2.5mm PAD)	24	工业
AD7147ACPZ-1REEL	Prodn	24 ld LFCSP (4x4mm 2.5mm PAD)	24	工业
AD7147ACPZ-500RL7	Prodn	24 ld LFCSP (4x4mm 2.5mm PAD)	24	工业
AD7147ACPZ-REEL	Prodn	24 ld LFCSP (4x4mm 2.5mm PAD)	24	工业
AD7147PACPZ-1500R7	Prodn		24	工业
EVAL-AD7147-1EBZ	Prodn	EVALUATION BOARDS	-	待定
EVAL-AD7147EBZ	Prodn	EVALUATION BOARDS	-	待定