- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄98179 > TC7135C/LI 1-CH 4-BIT DUAL-SLOPE ADC, PARALLEL ACCESS, PQCC28 PDF資料下載
參數(shù)資料
| 型號： | TC7135C/LI |
| 元件分類： | ADC |
| 英文描述： | 1-CH 4-BIT DUAL-SLOPE ADC, PARALLEL ACCESS, PQCC28 |
| 封裝： | PLASTIC, LCC-28 |
| 文件頁數(shù)： | 25/28頁 |
| 文件大?。?/td> | 443K |
| 代理商： | TC7135C/LI |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁當(dāng)前第25頁第26頁第27頁第28頁
TC7135
DS21460D-page 6
2007 Microchip Technology Inc.
3.0
DETAILED DESCRIPTION
All pin designations refer to the 28-pin PDIP package.
3.1
Dual-Slope Conversion Principles
The TC7135 is a dual-slope, integrating A/D converter.
An
understanding
of
the
dual-slope
conversion
technique will aid in following the detailed TC7135
operational theory.
The conventional dual-slope converter measurement
cycle has two distinct phases:
1.
Input signal integration.
2.
Reference voltage integration (de-integration).
The input signal being converted is integrated for a
fixed time period. Time is measured by counting clock
pulses. An opposite polarity constant reference voltage
is then integrated until the integrator output voltage
returns to zero. The reference integration time is
directly proportional to the input signal.
In
a
simple
dual-slope
converter,
a
complete
conversion requires the integrator output to “ramp-up”
and “ramp-down”.
A simple mathematical equation relates the input
signal, reference voltage and integration time:
EQUATION 3-1:
For a constant VIN:
EQUATION 3-2:
The dual-slope converter accuracy is unrelated to the
integrating resistor and capacitor values, as long as
they are stable during a measurement cycle. An
inherent benefit is noise immunity. Noise spikes are
integrated, or averaged, to zero during the integration
periods.
Integrated ADCs are immune to the large conversion
errors that plague successive approximation converters
in high-noise environments (see Figure 3-1).
FIGURE 3-1:
Basic Dual-Slope Converter.
3.2
Operational Theory
The TC7135 incorporates a system zero phase and
integrator output voltage zero phase to the normal two-
phase
dual-slope
measurement
cycle.
Reduced
system errors, fewer calibration steps and a shorter
overrange recovery time result.
The TC7135 measurement cycle contains four phases:
1.
System zero.
2.
Analog input signal integration.
3.
Reference voltage integration.
4.
Integrator output zero.
Internal analog gate status for each phase is shown in
TABLE 3-1:
INTERNAL ANALOG GATE STATUS
1
R
INTCINT
------------------------
V
IN T
()DT
0
T
INT
∫
V
REFTDEINT
R
INTCINT
--------------------------------
=
Where:
VREF = Reference voltage
TINT = Signal integration time (fixed)
TDEINT = Reference voltage integration time
(variable)
V
IN
V
REFTDEINT
T
INT
--------------------------------
=
+
-
REF
Voltage
Analog Input
Signal
+
-
Display
Switch
Drive
Control
Logic
In
teg
rat
or
Out
put
Clock
Counter
Polarity Control
Phase
Control
VIN ≈ VREF
Variable
Reference
Integrate
Time
Fixed
Signal
Integrate
Time
Integrator
Comparator
VIN ≈ 1/2 VREF
Conversion Cycle Phase
SWI
SWRI+SWRI-SWZ
SWR
SW1
SWIZ
Reference Figures
System Zero
—
Closed
—
Input Signal Integration
Closed
—
Reference Voltage Integration
—
Closed*
——
—
Closed
—
Integrator Output Zero
—
Closed
* Assumes a positive polarity input signal. SWRI would be closed for a negative input signal.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| TC7135C/LI713 | 1-CH 4-BIT DUAL-SLOPE ADC, PARALLEL ACCESS, PQCC28 |
| TC7135C/KW | 1-CH 4-BIT DUAL-SLOPE ADC, PARALLEL ACCESS, PQFP44 |
| TC7135C/BU | 1-CH 4-BIT DUAL-SLOPE ADC, PARALLEL ACCESS, PQFP64 |
| TC7135CJI | DUAL-SLOPE ADC, PARALLEL ACCESS, CDIP28 |
| TC7135CLI | DUAL-SLOPE ADC, PARALLEL ACCESS, PQCC28 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| TC7135CLI713 | 功能描述:LED顯示驅(qū)動器 4-1/2 Digit A/D BCD RoHS:否 制造商:Micrel 數(shù)位數(shù)量:5 片段數(shù)量: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PLCC-44 工作電源電壓:4.75 V to 11 V 最大電源電流:10 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Tube |
| TC7135CPI | 功能描述:LED顯示驅(qū)動器 4-1/2 Digit A/D BCD RoHS:否 制造商:Micrel 數(shù)位數(shù)量:5 片段數(shù)量: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PLCC-44 工作電源電壓:4.75 V to 11 V 最大電源電流:10 mA 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Tube |
| TC7135CPL | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:4-1/2 Digit A/D Converter |
| TC7136 | 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:Low Power 3-1/2 Digit Analog-to-Digital Converter |
| TC7136A | 制造商:TELCOM 制造商全稱:TelCom Semiconductor, Inc 功能描述:LOW POWER, 3-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTERS |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。