- 您现在的位置：买卖IC网 > PDF目录20100 > ICL7107SCPL (Intersil)IC ADC 3.5 DIGIT LED 40-DIP PDF资料下载
参数资料
| 型号： | ICL7107SCPL |
| 厂商： | Intersil |
| 文件页数： | 10/16页 |
| 文件大小： | 0K |
| 描述： | IC ADC 3.5 DIGIT LED 40-DIP |
| 标准包装： | 9 |
| 显示器类型： | LED |
| 配置： | 7 段显示 |
| 数字或字符： | A/D，3.5 位数字 |
| 电源电压： | 4.75 V ~ 5.25 V |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 通孔 |
| 封装/外壳： | 40-DIP（0.600"，15.24mm） |
| 供应商设备封装： | 40-DIP |
| 包装： | 管件 |
ICL7106, ICL7107, ICL7107S
Component Value Selection
Integrating Resistor
Both the buffer amplifier and the integrator have a class A
output stage with 100 μ A of quiescent current. They can
supply 4 μ A of drive current with negligible nonlinearity. The
integrating resistor should be large enough to remain in this
very linear region over the input voltage range, but small
enough that undue leakage requirements are not placed on
the PC board. For 2V full scale, 470k ? is near optimum and
similarly a 47k ? for a 200mV scale.
Integrating Capacitor
The integrating capacitor should be selected to give the
maximum voltage swing that ensures tolerance buildup will
not saturate the integrator swing (approximately. 0.3V from
either supply). In the ICL7106 or the ICL7107, when the
analog COMMON is used as a reference, a nominal +2V full-
scale integrator swing is fine. For the ICL7107 with +5V
supplies and analog COMMON tied to supply ground, a
± 3.5V to +4V swing is nominal. For three readings/second
(48kHz clock) nominal values for C lNT are 0.22 μ F and
0.10 μ F, respectively. Of course, if different oscillator
frequencies are used, these values should be changed in
inverse proportion to maintain the same output swing.
An additional requirement of the integrating capacitor is that
it must have a low dielectric absorption to prevent roll-over
errors. While other types of capacitors are adequate for this
application, polypropylene capacitors give undetectable
errors at reasonable cost.
Auto-Zero Capacitor
The size of the auto-zero capacitor has some influence on
the noise of the system. For 200mV full scale where noise is
very important, a 0.47 μ F capacitor is recommended. On the
2V scale, a 0.047 μ F capacitor increases the speed of
recovery from overload and is adequate for noise on this
scale.
Reference Capacitor
A 0.1 μ F capacitor gives good results in most applications.
However, where a large common mode voltage exists (i.e.,
the REF LO pin is not at analog COMMON) and a 200mV
scale is used, a larger value is required to prevent roll-over
Reference Voltage
The analog input required to generate full scale output (2000
counts) is: V lN = 2V REF . Thus, for the 200mV and 2V scale,
V REF should equal 100mV and 1V, respectively. However, in
many applications where the A/D is connected to a
transducer, there will exist a scale factor other than unity
between the input voltage and the digital reading. For
instance, in a weighing system, the designer might like to
have a full scale reading when the voltage from the
transducer is 0.662V. Instead of dividing the input down to
200mV, the designer should use the input voltage directly
and select V REF = 0.341V. Suitable values for integrating
resistor and capacitor would be 120k ? and 0.22 μ F. This
makes the system slightly quieter and also avoids a divider
network on the input. The ICL7107 with ± 5V supplies can
accept input signals up to ± 4V. Another advantage of this
system occurs when a digital reading of zero is desired for
V IN ≠ 0. Temperature and weighing systems with a variable
fare are examples. This offset reading can be conveniently
generated by connecting the voltage transducer between IN
HI and COMMON and the variable (or fixed) offset voltage
between COMMON and IN LO.
ICL7107 Power Supplies
The ICL7107 is designed to work from ± 5V supplies.
However, if a negative supply is not available, it can be
generated from the clock output with 2 diodes, 2 capacitors,
and an inexpensive lC. Figure 10 shows this application. See
ICL7660 data sheet for an alternative.
In fact, in selected applications no negative supply is
required. The conditions to use a single +5V supply are:
1. The input signal can be referenced to the center of the
common mode range of the converter.
2. The signal is less than ± 1.5V.
3. An external reference is used.
V+
CD4009
V+
OSC 1
f = ----------- For 48kHz Clock (3 Readings/sec),
error. Generally 1 μ F will hold the roll-over error to 0.5 count
in this instance.
Oscillator Components
For all ranges of frequency a 100k ? resistor is recommended
and the capacitor is selected from the equation:
0.45
RC
OSC 2
OSC 3
ICL7107
GND
V-
V- = 3.3V
1N914
0.047
μ F
1N914
+
10
μ F
-
C = 100pF.
FIGURE 10. GENERATING NEGATIVE SUPPLY FROM +5V
10
FN3082.8
相关PDF资料 |
PDF描述 |
|---|---|
| EMM43DRSI | CONN EDGECARD 86POS DIP .156 SLD |
| RBB13DHHN | CONN EDGE DUAL .050 DIP 26 POS |
| ICL7107CM44 | IC ADC 3.5 DIGIT LED 44-MQFP |
| VI-2NY-CV-F1 | CONVERTER MOD DC/DC 3.3V 99W |
| JMK212BJ335MG-T | CAP CER 3.3UF 6.3V 20% X5R 0805 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ICL7107SCPLZ | 功能描述:LED显示驱动器 ADC 3 5 DIG LED DRVR COM RoHS:否 制造商:Micrel 数位数量:5 片段数量: 安装风格:SMD/SMT 封装 / 箱体:PLCC-44 工作电源电压:4.75 V to 11 V 最大电源电流:10 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装:Tube |
| ICL7109 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:N-CHANNEL JFET |
| ICL7109 WAF | 制造商:Harris Corporation 功能描述: |
| ICL71091DL | 制造商:Harris Corporation 功能描述: |
| ICL7109C/D | 功能描述:显示驱动器和控制器 RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
发布紧急采购，3分钟左右您将得到回复。