参数资料
| 型号： | AT42QT2161-MMU |
| 厂商： | Atmel |
| 文件页数： | 2/14页 |
| 文件大小： | 0K |
| 描述： | IC TOUCH SENSOR 16KEY 28QFN |
| 标准包装： | 1 |
| 系列： | QMatrix™, QSlide™ |
| 类型： | 电容性 |
| 触摸面板接口： | 8，2 线 |
| 输入数/键： | 16 键，滑块 |
| 分辨率（位）： | 10 b |
| 评估套件： | * |
| 数据接口： | I²C，串行 |
| 电压基准： | 内部 |
| 电源电压： | 1.8 V ~ 5.5 V |
| 电流 - 电源： | 1.14mA |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-VFQFN 裸露焊盘 |
| 供应商设备封装： | 28-VQFN |
| 包装： | 标准包装 |
| 其它名称： | AT42QT2161-MMUDKR |
10
9614A–AT42–08/10
AT42QT2161
Figure 3-4.
Drive Pulse Roll-off and Dwell Time
Note:
The Dwell time is a minimum of ~250 ns - see Section 3.7
3.5
Sample Resistors
The sample resistors (Rs0 – Rs1) are used to perform single-slope ADC conversion of the
acquired charge on each Cs capacitor. These resistors directly control acquisition gain; larger
values of Rs will proportionately increase signal gain. For most applications Rs should be 1 M
.
Unused Y lines do not require an Rs resistor.
3.6
Signal Levels
The signal values should normally be in the range of 200 to 750 counts with properly designed
key shapes and values of Rs. However, long adjacent runs of X and Y lines can also artificially
boost the signal values, and induce signal saturation; this is to be avoided. The X-to-Y coupling
should come mostly from intra-key electrode coupling, not from stray X-to-Y trace coupling.
The signal swing from the smallest finger touch should preferably exceed 8 counts, with 12
being a reasonable target. The signal threshold setting (NTHR) should be set to a value
guaranteed to be less than the signal swing caused by the smallest touch.
Increasing the burst length (BL) parameter will increase the signal strengths, as will increasing
the sampling resistor (Rs) values.
3.7
Matrix Series Resistors
The X and Y matrix scan lines can use series resistors (Rx0 – Rx7 and Ry0 – Ry1 respectively)
for improved EMC performance (Figure 1-1 on page 4).
X drive lines require Rx in most cases to reduce edge rates and thus reduce RF emissions.
Values range from 1 k
to 20 k, typically 1 k.
Y lines need Ry to reduce EMC susceptibility problems and in some extreme cases, ESD.
Typical Y values are about 1 k
. Y resistors act to reduce noise susceptibility problems by
forming a natural low-pass filter with the Cs capacitors.
It is essential that the Rx and Ry resistors and Cs capacitors be placed very close to the chip.
Placing these parts more than a few millimeters away opens the circuit up to high frequency
interference problems (above 20 MHz) as the trace lengths between the components and the
chip start to act as RF antennae.
The upper limits of Rx and Ry are reached when the signal level and hence key sensitivity are
clearly reduced. The limits of Rx and Ry will depend on key geometry and stray capacitance,
and thus an oscilloscope is required to determine optimum values of both.
X drive
Lost charge due to
inadequate settling
before end of dwell time
Y gate
Dwell time
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AT42QT2161-MMU QS519 | 制造商:Atmel Corporation 功能描述:QSLIDE, 16 KEY - QMATRIX SENSO |
| AT42QT2640-AU | 功能描述:Capacitive Touch Buttons, Slider, Wheel 44-TQFP (10x10) 制造商:atmel 系列:QMatrix?? 包装:托盘 零件状态:有效 类型:按钮，滑块，拨轮 接近探测:无 输入数:最高 64 LED 驱动器通道:- 接口:SPI 分辨率:11 b 电压 - 电源:4.75 V ~ 5.25 V 电流 - 电源:13mA 工作温度:-40°C ~ 105°C 封装/外壳:44-TQFP 供应商器件封装:44-TQFP（10x10） 标准包装:160 |
| AT42QT2640-AUR | 功能描述:64 CHANNEL QMATRIX FMEA EN60730 制造商:microchip technology 系列:QMatrix?? 包装:剪切带（CT） 零件状态:在售 类型:按钮，滑块，拨轮 接近探测:无 输入数:最高 64 LED 驱动器通道:- 接口:SPI 分辨率:11 b 电压 - 电源:4.75 V ~ 5.25 V 电流 - 电源:13mA 工作温度:-40°C ~ 105°C 封装/外壳:44-TQFP 供应商器件封装:44-TQFP（10x10） 标准包装:1 |
| AT42QT4120 | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Patented spread-spectrum charge-transfer (transverse mode) |
| AT42QT4160 | 制造商:ATMEL 制造商全称:ATMEL Corporation 功能描述:Patented spread-spectrum charge-transfer (transverse mode) |
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