參數(shù)資料
型號: TC7136
廠商: TelCom Semiconductor, Inc.
英文描述: LOW POWER, 3-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTERS
中文描述: 低功耗,3-1/2數(shù)字模擬數(shù)字轉(zhuǎn)換器
文件頁數(shù): 5/12頁
文件大?。?/td> 192K
代理商: TC7136
3-251
TELCOM SEMICONDUCTOR, INC.
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3
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GENERAL THEORY OF OPERATION
(All Pin designations refer to 40-Pin Dip)
Dual-Slope Conversion Principles
The TC7136/A is a dual-slope, integrating analog-to-
digital converter. An understanding of the dual-slope con-
version technique will aid in following detailed TC7136/A
operational theory.
The conventional dual-slope converter measurement
cycle has two distinct phases:
(1) Input signal integration
(2) Reference voltage integration (deintegration)
The input signal being converted is integrated for a fixed
time period (t
SI
), measured by counting clock pulses. An
opposite polarity constant reference voltage is then inte-
grated until the integrator output voltage returns to zero. The
reference integration time is directly proportional to the input
signal (t
RI
).
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:
TC7136/A PIN DESCRIPTION
(Cont.)
Pin No.
40-Pin PDIP
Normal
(Reverse)
Name
C
REF
C
+
REF
Description
33
34
(8)
(7)
See pin 34.
A 0.1
μ
F capacitor is used in most applications. If a large common-mode
voltage exists (for example, the V
IN–
pin is not at analog common), and a 200
mV scale is used, a 1
μ
F capacitor is recommended and will hold the roll-over
error to 0.5 count.
See pin 36.
The analog input required to generate a full-scale output (1999 counts). Place
100 mV between pins 35 and 36 for 199.9 mV full scale. Place 1V between
pins 35 and 36 for 2V full scale. See paragraph on Reference Voltage.
Lamp test. When pulled HIGH (to V
+
) all segments will be turned ON and the
display should read –1888. It may also be used as a negative supply for exter-
nally-generated decimal points. See paragraph under Test for additional informa-
tion.
See pin 40.
See pin 40.
Pins 40, 39 and 38 make up the oscillator section. For a 48 kHz clock (3 readings per
second) connect pin 40 to the junction of a 180 k
resistor and a 50 pF capacitor. The
180 k
resistor is tied to pin 39 and the 50 pF capacitor is tied to pin 38.
35
(6)
(5)
V
V
REF
REF
36
(4)
TEST
37
38
39
(3)
(2)
(1)
OSC
3
OSC
2
OSC
1
For a constant V
IN
:
V
IN
= V
R
.
1
V
R
t
RI
RC
RC
V
IN
(t) dt =
,
t
SI
where:
V
R
= Reference voltage
t
SI
= Signal integration time (fixed)
t
RI
= Reference voltage integration time (variable).
Figure 1. Basic Dual-Slope Converter
+
REF
VOLTAGE
ANALOG
INPUT
SIGNAL
+
DISPLAY
SWITCH
DRIVER
CONTROL
LOGIC
I
O
CLOCK
COUNTER
POLARITY CONTROL
PHASE
CONTROL
VIN
VIN
VFULL SCALE
1.2 VFULL SCALE
VARIABLE
REFERENCE
INTEGRATE
TIME
FIXED
SIGNAL
INTEGRATE
TIME
INTEGRATOR
CINT
COMPARATOR
'
'
t
RI
t
[ ]
0
LOW POWER, 3-1/2 DIGIT
ANALOG-TO-DIGITAL CONVERTERS
TC7136
TC7136A
相關(guān)PDF資料
PDF描述
TC7136 Low Power 3-1/2 Digit Analog-to-Digital Converter
TC7136A Low Power 3-1/2 Digit Analog-to-Digital Converter
TC7136ACLW Low Power 3-1/2 Digit Analog-to-Digital Converter
TC7136ACPI Low Power 3-1/2 Digit Analog-to-Digital Converter
TC7136CLW Low Power 3-1/2 Digit Analog-to-Digital Converter
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
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
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TC7136ACKW713 功能描述:LCD 驅(qū)動器 Low Power RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube
TC7136ACLW 功能描述:LCD 驅(qū)動器 Low Power RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube
TC7136ACLW713 功能描述:LCD 驅(qū)動器 Low Power RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube