參數(shù)資料
型號(hào)： AD7879ACPZ-RL
廠商： Analog Devices Inc
文件頁數(shù)： 8/41頁
文件大?。?/td> 0K
描述： IC ADC 12BIT CTLR TOUCH 16LFCSP
標(biāo)準(zhǔn)包裝： 1
類型： 電阻
觸摸面板接口： 4 線
輸入數(shù)/鍵： 1 TSC
分辨率（位）： 12 b
評(píng)估套件： 可供
數(shù)據(jù)接口： 串行，SPI?
數(shù)據(jù)速率/采樣率 (SPS，BPS)： 105k
電壓基準(zhǔn)： 內(nèi)部
電源電壓： 1.6 V ~ 3.6 V
工作溫度： -40°C ~ 85°C
安裝類型： 表面貼裝
封裝/外殼： 16-VQFN 裸露焊盤，CSP
供應(yīng)商設(shè)備封裝： 16-LFCSP-VQ
包裝： 標(biāo)準(zhǔn)包裝
其它名稱： AD7879ACPZ-RLDKR
AD7879/AD7889
Rev. C | Page 15 of 40
TOUCH-PRESSURE MEASUREMENT
The pressure applied to the touch screen by a pen or finger can
also be measured with the AD7879/AD7889 using some simple
calculations. The contact resistance between the X and Y plates
is measured, providing a good indication of the size of the
depressed area and, therefore, the applied pressure. The area of
the spot that is touched is proportional to the size of the object
touching it. The size of this resistance (RTOUCH) can be calculated
using two different methods.
First Method
The first method requires the user to know the total resistance
of the X-plate tablet (RX). Three touch screen conversions are
required: measurement of the X position, XPOSITION (Y+ input);
measurement of the X+ input with the excitation voltage applied
to Y+ and X (Z1 measurement); and measurement of the Y
input with the excitation voltage applied to Y+ and X (Z2
measurement). These three measurements are illustrated in
The AD7879/AD7889 have two special ADC channel settings
that configure the X and Y switches for the Z1 and Z2 measure-
ments and store the results in the Z1 and Z2 result registers. The
Z1 measurement is selected by setting the CHNL ADD[2:0] bits
to 101 in Control Register 1 (Address 0x01); the result is stored
in the X+ (Z1) result register (Address 0x0A). The Z2 measurement
is selected by setting the CHNL ADD[2:0] bits to 100 in Control
Register 1 (Address 0x01); the result is stored in the Y (Z2)
result register (Address 0x0B).
The touch resistance (RTOUCH) can then be calculated using the
following equation:
RTOUCH = (RXPLATE) × (XPOSITION/4096) × [(Z2/Z1) 1]
(2)
07667-
026
Y–
Y+
X–
X+
TOUCH
RESISTANCE
MEASURE
Z1 POSITION
X–
X+
Y–
Y+
TOUCH
RESISTANCE
MEASURE
X POSITION
Y–
Y+
X–
X+
TOUCH
RESISTANCE
MEASURE
Z2 POSITION
Figure 26. Three Measurements Required for Touch Pressure
Second Method
The second method requires the user to know the resistance of
the X-plate and Y-plate tablets. Three touch screen conversions
are required: a measurement of the X position (XPOSITION), the
Y position (YPOSITION), and the Z1 position.
The following equation also calculates the touch resistance
(RTOUCH):
RTOUCH = RXPLATE × (XPOSITION/4096) × [(4096/Z1) 1]
RYPLATE × [1 (YPOSITION/4096)]
(3)
TEMPERATURE MEASUREMENT
A temperature measurement option called the single-conversion
method is available on the AD7879/AD7889. The conversion
method requires only a single measurement on ADC Channel
001. The results are stored in the temperature conversion result
register (Address 0x0D). The AD7879/AD7889 do not provide
an explicit output of the temperature reading; the system must
perform some external calculations. This method is based on
an on-chip diode measurement.
The acquisition time is fixed at 16 ms for temperature
measurement.
Conversion Method
The conversion method makes use of the fact that the tempera-
ture coefficient of a silicon diode is approximately 2.1 mV/°C.
However, this small change is superimposed on the diode forward
voltage, which can have a wide tolerance. Therefore, it is necessary
to calibrate by measuring the diode voltage at a known temperature
to provide a baseline from which the change in forward voltage
with temperature can be measured. This method provides a
resolution of approximately 0.3°C and a predicted accuracy
of ±2°C.
The temperature limit comparison is performed on the result
in the temperature conversion result register (Address 0x0D),
which is the measurement of the diode forward voltage. The
values programmed into the high and low limits should be
referenced to the calibrated diode forward voltage to make
accurate limit comparisons.
相關(guān)PDF資料
PDF描述
VI-201-MX-F2 CONVERTER MOD DC/DC 12V 75W
VI-JWR-MX-F4 CONVERTER MOD DC/DC 7.5V 75W
MS27468T25A35SC CONN RCPT 128POS JAM NUT W/SCKT
VI-JWR-MX-F3 CONVERTER MOD DC/DC 7.5V 75W
VI-JWR-MX-F1 CONVERTER MOD DC/DC 7.5V 75W
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7879WACPZ-R5 功能描述:Touchscreen Controller 4-Wire 12 bit SPI Interface 16-LFCSP-VQ (4x4) 制造商:analog devices inc. 系列:- 包裝:剪切帶（CT） 零件狀態(tài):在售 類型:電阻 觸摸面板接口:4 線 輸入/按鍵數(shù):1 TSC 分辨率（位）:12 b 評(píng)估工具:* 數(shù)據(jù)接口:SPI 數(shù)據(jù)速率/采樣率（SPS，BPS）:105k 電壓基準(zhǔn):外部 電壓 - 電源:1.6 V ~ 3.6 V 電流 - 電源:- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:16-VQFN 裸露焊盤，CSP 供應(yīng)商器件封裝:16-LFCSP-VQ（4x4） 標(biāo)準(zhǔn)包裝:1
AD7879WACPZ-RL 功能描述:TOUCH SCREEN CONTROLLER 制造商:analog devices inc. 系列:- 包裝:帶卷（TR） 零件狀態(tài):在售 觸摸屏:4 線電阻式 分辨率（位）:12 b 接口:SPI 電壓基準(zhǔn):外部 電壓 - 電源:1.6 V ~ 3.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:16-VQFN 裸露焊盤，CSP 供應(yīng)商器件封裝:16-LFCSP-VQ（4x4） 標(biāo)準(zhǔn)包裝:5,000
AD7879WARUZ-RL 功能描述:IC ADC 12BIT CTLR TOUCH 16TSSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 觸摸屏控制器 系列:- 標(biāo)準(zhǔn)包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數(shù)/鍵:- 分辨率（位）:- 評(píng)估套件:* 數(shù)據(jù)接口:- 數(shù)據(jù)速率/采樣率 (SPS，BPS):- 電壓基準(zhǔn):- 電源電壓:- 電流 - 電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:16-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:帶卷 (TR)
AD7879WARUZ-RL7 功能描述:IC ADC 12BIT CTLR TOUCH 16TSSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 觸摸屏控制器 系列:- 標(biāo)準(zhǔn)包裝:96 系列:- 類型:- 觸摸面板接口:- 輸入數(shù)/鍵:- 分辨率（位）:- 評(píng)估套件:* 數(shù)據(jù)接口:- 數(shù)據(jù)速率/采樣率 (SPS，BPS):- 電壓基準(zhǔn):- 電源電壓:- 電流 - 電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:16-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:帶卷 (TR)
AD7880BCHIPS 功能描述:12 Bit Analog to Digital Converter 2 Input 1 SAR Die 制造商:analog devices inc. 系列:- 包裝:管件 零件狀態(tài):上次購買時(shí)間 位數(shù):12 采樣率（每秒）:66k 輸入數(shù):2 輸入類型:單端 數(shù)據(jù)接口:并聯(lián) 配置:S/H-ADC 無線電 - S/H:ADC:1:1 A/D 轉(zhuǎn)換器數(shù):1 架構(gòu):SAR 參考類型:外部，電源 電壓 - 電源，模擬:5V 電壓 - 電源，數(shù)字:5V 特性:- 工作溫度:-40°C ~ 85°C 封裝/外殼:模具 供應(yīng)商器件封裝:模具 標(biāo)準(zhǔn)包裝:1
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。

采購需求

(若只采購一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購

我的聯(lián)系方式

*
*
*