參數(shù)資料
型號: SP7800AKS
英文描述: 12-Bit 3ms Sampling A/D Converter
中文描述: 12位為3ms采樣A / D轉(zhuǎn)換器
文件頁數(shù): 5/13頁
文件大?。?/td> 171K
代理商: SP7800AKS
SP7800ADS/02
SP7800A 12-Bit 3
μ
s Sampling A/D Converter
5
Copyright 2000 Sipex Corporation
ing resistors provide industry–standard input ranges
of
±
5V or
±
10V. The 24-pin
SP7800A
is available in
plastic DIP, and SOIC packages and it operates from
a single +5V supply. The
SP7800A
is available in
grades specified over the 0
°
C to +70
°
C commercial
temperature ranges.
edge of R/C will enable the output data pins, and
the data from the previous conversion becomes
valid. The falling edge then puts the
SP7800A
in
a hold mode, and initiates a new conversion.
The
SP7800A
will begin acquiring a new sample
just prior to BUSY output rising, and will track the
input signal until the next conversion is started.
For use with an 8-bit bus, the data can be read out
in two bytes under the control of HBE. With a
LOW input on HBE, at the end of a conversion, the
8 LSBs of data are loaded into the output drivers D
7
– D
and D
–D
. Taking HBE HIGH then loads the
4 MSBs on output drivers D
3
–D
0
, with D
7
–D
4
being forced LOW.
Analog Input Ranges
The
SP7800A
offers two standard bipolar input
ranges:
±
10V and
±
5V. If a
±
10V range is re-
quired, the analog input signal should be con-
nected to pin 1. A signal requiring a
±
5V range
should be connected to pin 2. In either case, the
other pin of the two must be grounded or connected
to the adjustment circuits described in the section
on calibration.
Controlling The SP7800A
The
SP7800A
can be easily interfaced to most
microprocessor-based and other digital systems. The
microprocessor may take full control of each conver-
sion, or the
SP7800A
may operate in a stand-alone
mode, controlled only by the R/C input. Full control
consists of initiating the conversion and reading the
output data at user command, transmitting data either
all 12-bits in one parallel word, or in two 8-bit bytes.
The three control inputs (CS, R/C and HBE) are all
TTL/CMOS compatible. The functions of the control
lines are shown in
Table 1
.
For stand-alone operation, control of the
SP7800A
is accomplished by a single control line connected
to R/C. In this mode, CS and HBE are connected
to GND. The output data are presented as 12-bit
words. The stand-alone mode is used in systems
containing dedicated input ports which do not
require full bus interface capability.
Conversion is initiated by a HIGH-to-LOW transition
OPERATION...
Basic Operation
Figure 1
shows the simple hookup circuit required
to operate the
SP7800A
in a
±
10V range in the
Convert Mode. A convert command arriving on
R/C, (a pulse taking R/C LOW for a minimum of
40ns) puts the
SP7800A
in the HOLD mode, and
a conversion is started. The falling edge of R/C
establishes the sampling instant of the A/D; it must
therefore have very low jitter. BUSY will be held
LOW during the conversion, and rises only after
the conversion is completed and the data has been
transferred to the output drivers. Thus, the rising
edge can be used to read the data from the conver-
sion. Also, during conversion, the BUSY signal
puts the output data lines in Hi-Z states and inhibits
the input lines. This means that pulses on R/C are
ignored, so that new conversions cannot be initi-
ated during a conversion, either as a result of
spurious signals or to short-cycle the
SP7800A.
In the Read Mode, the input to R/C is kept nor-
mally LOW, and a HIGH pulse is used to read data
and initiate a conversion. In this mode, the rising
Figure 1. Basic
±
10V Operation
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
(D0
Busy
Convert
0.1μF
6.8μF+
+5V
+5V
+5V
N.C.
BUSY
CS
R/C
HBE
D0 (LSB)
D1
D2
D3
DGND
IN 1
IN 2
N.C.
AGND
D11 (MSB)
D10
D9
D8
D7
D6
D5
D4
(D11
Out
Input
相關(guān)PDF資料
PDF描述
SP782 Programmable Charge Pump
SP782CP Programmable Charge Pump
SP782CT Programmable Charge Pump
SP784 Programmable Charge Pump
SP784CP Programmable Charge Pump
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SP7805AIS WAF 制造商:Texas Instruments 功能描述:
SP7805V2-L 功能描述:DC/DC 開關(guān)控制器 30 TERMINAL 1A POS RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
SP7805V2-L/TR 功能描述:DC/DC 開關(guān)控制器 30 TERMINAL 1A POS RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
SP7805V2-L-TR 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:3-Terminal Positive Regulators
SP7805V-L 功能描述:DC/DC 開關(guān)控制器 30 TERMINAL 1A POS RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK