參數(shù)資料
型號： TSC2046IRGVT
廠商： TEXAS INSTRUMENTS INC
元件分類： 消費家電
英文描述： SPECIALTY CONSUMER CIRCUIT, PQCC16
封裝： 4 X 4 MM, 1MM HEIGHT, GREEN, PLASTIC, QFN-16
文件頁數(shù)： 4/33頁
文件大?。?/td> 774K
代理商： TSC2046IRGVT
TSC2046
SBAS265G OCTOBER 2002 REVISED JANUARY 2008
www.ti.com
12
Converter
+IN
+REF
Y+
+V
CC
X+
Y
GND
REF
IN
Figure 5. Simplified Diagram of Differential
Reference (SER/DFR low, Y switches enabled,
X+ is analog input)
As a final note about the differential reference mode, it
must be used with +VCC as the source of the +REF voltage
and cannot be used with VREF. It is possible to use a
high-precision reference on VREF and single-ended
reference mode for measurements which do not need to
be ratiometric. In some cases, it is possible to power the
converter directly from a precision reference. Most
references can provide enough power for the TSC2046,
but might not be able to supply enough current for the
external load (such as a resistive touch screen).
TOUCH SCREEN SETTLING
In some applications, external capacitors may be required
across the touch screen for filtering noise picked up by the
touch screen (e.g., noise generated by the LCD panel or
backlight circuitry). These capacitors provide a low-pass
filter to reduce the noise, but cause a settling time
requirement when the panel is touched that typically
shows up as a gain error. There are several methods for
minimizing or eliminating this issue. The problem is that
the input and/or reference has not settled to the final
steady-state value prior to the ADC sampling the input(s)
and providing the digital output. Additionally, the reference
voltage may still be changing during the measurement
cycle. Option 1 is to stop or slow down the TSC2046 DCLK
for the required touch screen settling time. This allows the
input and reference to have stable values for the Acquire
period (3 clock cycles of the TSC2046; see Figure 9). This
works for both the single-ended and the differential modes.
Option 2 is to operate the TSC2046 in the differential mode
only for the touch screen measurements and command
the TSC2046 to remain on (touch screen drivers ON) and
not go into power-down (PD0 = 1). Several conversions
are made depending on the settling time required and the
TSC2046 data rate. Once the required number of
conversions have been made, the processor commands
the TSC2046 to go into its power-down state on the last
measurement. This process is required for X-Position,
Y-Position, and Z-Position measurements. Option 3 is to
operate in the 15 Clock-per-Conversion mode, which
overlaps the analog-to-digital conversions and maintains
the touch screen drivers on until commanded to stop by the
processor (see Figure 13).
TEMPERATURE MEASUREMENT
In some applications, such as battery recharging, a
measurement of ambient temperature is required. The
temperature
measurement
technique
used
in
the
TSC2046 relies on the characteristics of a semiconductor
junction operating at a fixed current level. The forward
diode voltage (VBE) has a well-defined characteristic
versus temperature. The ambient temperature can be
predicted in applications by knowing the +25
°C value of
the VBE voltage and then monitoring the delta of that
voltage as the temperature changes. The TSC2046 offers
two modes of operation. The first mode requires
calibration at a known temperature, but only requires a
single reading to predict the ambient temperature. A diode
is used (turned on) during this measurement cycle. The
voltage across the diode is connected through the MUX for
digitizing the forward bias voltage by the ADC with an
address of A2 = 0, A1 = 0, and A0 = 0 (see Table 1 and
Figure 6 for details). This voltage is typically 600mV at
+25
°C with a 20A current through the diode. The absolute
value of this diode voltage can vary a few millivolts.
However, the TC of this voltage is very consistent at
–2.1mV/
°C. During the final test of the end product, the
diode voltage would be stored at a known room
temperature, in memory, for calibration purposes by the
user.
The
result
is
an
equivalent
temperature
measurement resolution of 0.3
°C/LSB (in 12-bit mode).
ADC
MUX
TE M P 0
TE M P 1
+V
CC
Figure 6. Functional Block Diagram of
Temperature Measurement
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參數(shù)描述
TSC2046IRGVTG4 功能描述:觸摸屏轉(zhuǎn)換器和控制器 4-Wire w/low voltage digital I/O RoHS:否 制造商:Microchip Technology 類型:Resistive Touch Controllers 輸入類型:3 Key 數(shù)據(jù)速率:140 SPS 分辨率:10 bit 接口類型:4-Wire, 5-Wire, 8-Wire, I2C, SPI 電源電壓:2.5 V to 5.25 V 電源電流:17 mA 工作溫度:- 40 C to + 85 C 封裝 / 箱體:SSOP-20
TSC2046IZQCR 功能描述:觸摸屏轉(zhuǎn)換器和控制器 4-Wire w/low voltage digital I/O RoHS:否 制造商:Microchip Technology 類型:Resistive Touch Controllers 輸入類型:3 Key 數(shù)據(jù)速率:140 SPS 分辨率:10 bit 接口類型:4-Wire, 5-Wire, 8-Wire, I2C, SPI 電源電壓:2.5 V to 5.25 V 電源電流:17 mA 工作溫度:- 40 C to + 85 C 封裝 / 箱體:SSOP-20
TSC2046IZQCR-90 功能描述:觸摸屏轉(zhuǎn)換器和控制器 4-Wire w/low voltage digital I/O RoHS:否 制造商:Microchip Technology 類型:Resistive Touch Controllers 輸入類型:3 Key 數(shù)據(jù)速率:140 SPS 分辨率:10 bit 接口類型:4-Wire, 5-Wire, 8-Wire, I2C, SPI 電源電壓:2.5 V to 5.25 V 電源電流:17 mA 工作溫度:- 40 C to + 85 C 封裝 / 箱體:SSOP-20
TSC2046IZQCT 功能描述:觸摸屏轉(zhuǎn)換器和控制器 4-Wire w/low voltage digital I/O RoHS:否 制造商:Microchip Technology 類型:Resistive Touch Controllers 輸入類型:3 Key 數(shù)據(jù)速率:140 SPS 分辨率:10 bit 接口類型:4-Wire, 5-Wire, 8-Wire, I2C, SPI 電源電壓:2.5 V to 5.25 V 電源電流:17 mA 工作溫度:- 40 C to + 85 C 封裝 / 箱體:SSOP-20
TSC2059 制造商:TSC 制造商全稱:Taiwan Semiconductor Company, Ltd 功能描述:General Purpose NPN Transistor
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