參數(shù)資料
型號: ADCV08832
廠商: National Semiconductor Corporation
英文描述: Low Voltage, 8-Bit Serial I/O CMOS A/D Converter with Sample/Hold Function
中文描述: 低電壓,8位串行I / O的CMOS的A / D轉(zhuǎn)換器的采樣/保持功能
文件頁數(shù): 9/14頁
文件大小: 259K
代理商: ADCV08832
Timing Diagrams
(Continued)
Functional Description
1.0 MULTIPLEXER ADDRESSING
The design of these converters utilizes a comparator struc-
ture with built-in sample-and-hold which provides for a differ-
ential analog input to be converted by a successive approxi-
mation routine.
In differential mode the voltage converted is always the
difference between the assigned “+” input terminal and the
“” input terminal. The polarity of each input terminal of the
pair indicates which line the converter expects to be the most
positive. If the assigned “+” input voltage is less than the “”
input voltage the converter responds with an all zeros output
code.
The multiplexor at the analog inputs of the converter pro-
vides for the software-configurable single-ended or differen-
tial operation. The analog signal conditioning required in
transducer-based data acquisition systems is significantly
simplified with this type of input flexibility. A single
ADCV08832 can handle ground referenced inputs, differen-
tial inputs, as well as signals with some arbitrary reference
voltage.
The input configuration is assigned during the MUX address-
ing sequence, prior to the start of a conversion. The MUX
address selects which of the analog inputs will be enabled,
and whether this input is single-ended or differential. In
addition to selecting the differential mode, the polarity may
also be selected. Channel 0 may be selected as the positive
input and channel 1 as the negative input or vice versa. This
programmability is illustrated in the MUX addressing tables.
MUX Addressing: ADCV08832
Single-Ended MUX Mode
MUX Address
Start
Bit
DIF
1
1
1
1
Channel
#
SGL/
ODD/
SIGN
0
1
0
1
+
+
Differential MUX Mode
MUX Address
Start
Bit
DIF
1
0
1
0
Channel
#
SGL/
ODD/
SIGN
0
1
0
1
+
+
Since the input configuration is under software control, it can
be modified as required before each conversion. A channel
could be treated as a single-ended, ground referenced input
for one conversion; then, it could be reconfigured as part of
a differential channel for another conversion.
The analog input voltages for each channel can range from
50mV below ground to 50mV above Vcc without degrading
conversion accuracy.
2.0 THE DIGITAL INTERFACE
An important characteristic of this converter is the serial
communication interface with the controlling processor. The
serial interface facilitates versatile operation in a small pack-
age. The small converter can be placed close to the analog
source, converting a low level signal into a noise immune bit
stream.
To understand the operation of these converters, it is best to
refer to the Timing Diagrams and Functional Block Diagram
and follow a complete conversion sequence.
1.
A conversion is initiated by pulling the CS (chip select)
line low. This line must be held low for the entire con-
version (13 Clock Cycles). The converter is now waiting
for a start bit and its MUX assignment word.
2.
On each rising edge of the clock the data on the DI line
is clocked into the MUX address shift register. The start
bit is the first logic
1
that appears on this line (all
leading zeros are ignored). Following the start bit the
converter expects the next 2 bits to be the MUX address.
3.
A conversion begins
1
2
clock after the odd/sign bit is
latched. An interval of
1
2
clock period (where nothing
happens) is automatically inserted to allow the selected
MUX channel to settle to a final analog input value. The
DI line is ignored for the remainder of the conversion.
4.
On the falling edge of the 3rd clock. DO exits TRI-STATE
and provides a leading zero for this one clock period of
MUX settling time.
ADCV08832 Timing
DS200084-26
A
www.national.com
9
相關(guān)PDF資料
PDF描述
ADCV08832CIMX Low Voltage, 8-Bit Serial I/O CMOS A/D Converter with Sample/Hold Function
ADCV08832CIM Low Voltage, 8-Bit Serial I/O CMOS A/D Converter with Sample/Hold Function
ADD3501 3 1/2 DIGIT DVM WITH MULTIPLEXED 7-SEGMENT OUTPUT
ADD3501CCN 3 1/2 DIGIT DVM WITH MULTIPLEXED 7-SEGMENT OUTPUT
ADD3701 3 3/4 DIGIT DVM WITH MULTIPLEXED 7-SEGMENT OUTPUT
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADCV08832CIM 制造商:Rochester Electronics LLC 功能描述: 制造商:Texas Instruments 功能描述:
ADCV08832CIM/NOPB 功能描述:IC ADC 8BIT SRL I/O CMOS 8-SOIC RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:- 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:2,500 系列:- 位數(shù):12 采樣率(每秒):3M 數(shù)據(jù)接口:- 轉(zhuǎn)換器數(shù)目:- 功率耗散(最大):- 電壓電源:- 工作溫度:- 安裝類型:表面貼裝 封裝/外殼:SOT-23-6 供應商設(shè)備封裝:SOT-23-6 包裝:帶卷 (TR) 輸入數(shù)目和類型:-
ADCV08832CIMX 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
ADCV08832CIMX/NOPB 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
ADCVREFN 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:32-Bit AVR UC3 C Series Schematic Checklist