參數(shù)資料
型號(hào)： TC7109CKW
廠商： TelCom Semiconductor, Inc.
英文描述： 12-BIT UP-COMPATIBLE ANALOG-TO-DIGITAL CONVERTERS
中文描述： 12位向上兼容的模擬數(shù)字轉(zhuǎn)換器
文件頁(yè)數(shù)： 15/21頁(yè)
文件大小： 274K
代理商： TC7109CKW
3-105
TELCOM SEMICONDUCTOR, INC.
7
6
5
4
3
1
2
8
The inner foil of C
AZ
should be connected to pin 31 and
the outer foil to the RC summing junction. The inner foil of
C
INT
should be connected to the RC summing junction and
the outer foil to pin 32 for best rejection of stray pickups. For
low leakage at temperatures above +85
°
C, use Teflon
capacitors.
Reference Capacitor
A 1
μ
F capacitor is recommended for most circuits.
However, where a large common-mode voltage exists, a
larger value is required to prevent roll-over error (e.g., the
reference low is not analog common), and a 409.6 mV scale
is used. The roll-over error will be held to 0.5 count with a 10
μ
F capacitor. For temperatures above +80
°
C use Teflon or
equivalent capacitors for their low leakage characteristics.
Reference Voltage
To generate full-scale output of 4096 counts, the analog
input required is V
IN
= 2 V
REF
. For 409.6 mV full scale, use
a reference of 204.8 mV. In many applications, where the
ADC is connected to a transducer, a scale factor will exist
between the input voltage and the digital reading. For
instance, in a measuring system, the designer might like to
have a full-scale reading when the voltage for the transducer
is 700 mV. Instead of dividing the input down to 409.6 mV,
the designer should use the input voltage directly and select
V
REF
= 350 mV. Suitable values for integrating resistor and
capacitor would be 34 k
and 0.15
μ
F. This makes the
system slightly quieter and also avoids a divider network on
the input. Another advantage of this system occurs when
temperature and weight measurements with an offset or tare
are desired for non-zero input. The offset may be introduced
by connecting the voltage output of the transducer between
common and analog high, and the offset voltage between
common and analog low, observing polarities carefully. In
processor-based systems using the TC7109A, it may be
more desirable to use software and perform this type of
scaling or tare subtraction digitally.
Reference Sources
A major factor in the absolute accuracy of the ADC is the
stability of the reference voltage. The 12-bit resolution of the
TC7109A is one part in 4096, or 244 ppm. Thus, for the on-
board reference temperature coefficient of 70 ppm/
°
C, a
temperature difference of 3
°
C will introduce a one-bit abso-
lute error. Where the ambient temperature is not controlled,
or where high-accuracy absolute measurements are being
made, it is recommended that an external high-quality
reference be used.
A reference output (pin 29) is provided which may be
used with a resistive divider to generate a suitable reference
voltage (20 mA may be sunk without significant variation in
output voltage). A pull-up bias device is provided which
sources about 10
μ
A. The output voltage is nominally 2.8V
below V
+
. When using the on-board reference, REF OUT
(pin 29) should be connected to REF
–
(pin 39), and REF
+
should be connected to the wiper of a precision potentiom-
eter between REF OUT and V
+
. The test circuit shows the
circuit for a 204.8 mV reference, generated by a 2 k
precision potentiometer in series with a 24 k
fixed resistor.
Interfacing
Direct Mode
Combinations of chip-enable and byte-enable control
signals which may be used when interfacing the TC7109A
to parallel data lines are shown in Figure 12. The CE/LOAD
input may be tied low, allowing either byte to be controlled
by its own enable (Figure 12A). Figure 12B shows the
HBEN and LBEN as flag inputs, and CE/LOAD as a master
enable, which could be the READ strobe available from
most microprocessors. Figure 12C shows a configuration
where the two byte enables are connected together. The
CE/LOAD is a chip enable, and the HBEN and LBEN may
be used as a second chip enable, or connected to ground.
The 14 data outputs will be enabled at the same time. In
the direct MODE, SEND should be tied to V
+
.
Figure 13 shows interfacing several TC7109A's to a
bus, ganging the HBEN and LBEN signals to several con-
verters together, and using the CE/LOAD input to select
the desired converter.
Figures 14–19 give practical circuits utilizing the paral-
lel three-state output capabilities of the TC7109A. Figure
14 shows parallel interface to the Intel MCS-48, -80 and -
85 systems via an 8255 PPI, where the TC7109A data
outputs are active at all times. The 8155 I/O ports may be
used in an identical manner. This interface can be used in a
read-after-update sequence, as shown in Figure 15. The
data is accessed by the high-to-low transition of the STA-
TUS driving an interrupt to the microprocessor.
The RUN/HOLD input is also used to initiate conver-
sions under software control. Figure 16 gives an interface
to Motorola MC6800 or MOS Technology MCS650X sys-
tem.
An interrupt is generated through the Control Register
B, CB1 line from the high-to-low transition of the STATUS
output. The RUN/HOLD pin is controlled by CB2 through
Control Register B, allowing software control of conver-
sions.
TC7109
TC7109A
12-BIT
μ
P-COMPATIBLE
ANALOG-TO-DIGITAL CONVERTERS
相關(guān)PDF資料
PDF描述
TC7109IJL 12-BIT UP-COMPATIBLE ANALOG-TO-DIGITAL CONVERTERS
TC7109 12-BIT UP-COMPATIBLE ANALOG-TO-DIGITAL CONVERTERS
TC7109A 12-BIT UP-COMPATIBLE ANALOG-TO-DIGITAL CONVERTERS
TC7109ACLW 12-BIT UP-COMPATIBLE ANALOG-TO-DIGITAL CONVERTERS
TC7109ACPL 12-BIT UP-COMPATIBLE ANALOG-TO-DIGITAL CONVERTERS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TC7109CKW713 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 13 Bit Fast Recovery RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
TC7109CLW 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 13 Bit Fast Recovery RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
TC7109CLW713 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 13 Bit Fast Recovery RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
TC7109CPL 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 13 Bit Fast Recovery RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
TC7109CPL 制造商:Microchip Technology Inc 功能描述:IC 12BIT ADC 7109 DIP40
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)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(gòu)。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(gòu)。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(gòu)

我的聯(lián)系方式

*
*
*