欢迎访问ic37.com |
会员登录 免费注册
发布采购

TC7106A 参数 Datasheet PDF下载

TC7106A图片预览
型号: TC7106A
PDF下载: 下载PDF文件 查看货源
内容描述: 3-1 / 2位A / D转换器 [3-1/2 DIGIT A/D CONVERTERS]
分类和应用: 转换器
文件页数/大小: 19 页 / 296 K
品牌: TELCOM [ TELCOM SEMICONDUCTOR, INC ]
 浏览型号TC7106A的Datasheet PDF文件第2页浏览型号TC7106A的Datasheet PDF文件第3页浏览型号TC7106A的Datasheet PDF文件第4页浏览型号TC7106A的Datasheet PDF文件第5页浏览型号TC7106A的Datasheet PDF文件第7页浏览型号TC7106A的Datasheet PDF文件第8页浏览型号TC7106A的Datasheet PDF文件第9页浏览型号TC7106A的Datasheet PDF文件第10页  
3-1/2 DIGIT A/D CONVERTERS  
TC7106  
TC7106A  
TC7107  
TC7107A  
PIN DESCRIPTION (Cont.)  
Pin No.  
Pin No.  
40-Pin PDIP 40-Pin PDIP  
(Normal)  
(Reverse)  
Symbol  
Description  
34  
(7)  
C+REF  
A 0.1µF capacitor is used in most applications. If a large common-  
mode voltage exists (for example, the VIN pin is not at analog  
common), and a 200mV scale is used, a 1µF capacitor is recom-  
mended and will hold the roll-over error to 0.5 count.  
35  
36  
(6)  
(5)  
VREF  
V+REF  
See pin 36.  
The analog input required to generate a full-scale output (1999  
counts). Place 100mV between pins 35 and 36 for 199.9mV  
full-scale. Place 1V between pins 35 and 36 for 2V full scale. See  
paragraph on REFERENCE VOLTAGE.  
37  
(4)  
Test  
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 externally-generated decimal points. See paragraph under  
TEST for additional information.  
38  
39  
40  
(3)  
(2)  
(1)  
OSC3  
OSC2  
OSC1  
See pin 40.  
See pin 40.  
Pins 40, 39, 38 make up the oscillator section. For a 48kHz clock  
(3 readings per section), connect pin 40 to the junction of a 100kΩ  
resistor and a 100pF capacitor. The 100kresistor is tied to pin 39  
and the 100pF capacitor is tied to pin 38.  
where:  
GENERAL THEORY OF OPERATION  
DUAL SLOPE CONVERSION PRINCIPLES  
VR = Reference Voltage  
TSI = Signal Integration Time (Fixed)  
TRI = Reference Voltage Integration Time (Variable)  
(All Pin Designations Refer to the 40-Pin DIP)  
The TC7106A and TC7107A are dual slope, integrating  
analog-to-digital converters. An understanding of the dual  
slope conversion technique will aid in following the detailed  
operation theory.  
The conventional dual slope converter measurement  
cycle has two distinct phases:  
For a constant VIN:  
TRI  
VIN = VR  
TSI  
C
ANALOG  
INPUT  
Input Signal Integration  
Reference Voltage Integration (Deintegration)  
INTEGRATOR  
SIGNAL  
COMPARATOR  
+
+
The input signal being converted is integrated for a fixed  
time period (TSI). 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 (TRI). (Figure 2A).  
+/–  
SWITCH  
DRIVER  
CLOCK  
PHASE  
REF  
VOLTAGE  
CONTROL  
LOGIC  
CONTROL  
POLARITY CONTROL  
In a simple dual slope converter a complete conversion  
requires the integrator output to “ramp-up” and “ramp-  
down.”  
Asimplemathematicalequationrelatestheinputsignal,  
reference voltage and integration time:  
COUNTER  
DISPLAY  
V
V
V
IN  
IN  
FULL SCALE  
1/2 V  
FULL SCALE  
FIXED VARIABLE  
SIGNAL REFERENCE  
INTEGRATE INTEGRATE  
TIME TIME  
TSI  
VRTRI  
RC  
1
RC  
VIN(t)dt =  
0
Figure 2A. Basic Dual Slope Converter  
3-188  
TELCOM SEMICONDUCTOR, INC.