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參數(shù)資料
| 型號(hào)： | SP8505 |
| 元件分類： | 串行ADC |
| 英文描述： | 12-Bit Sampling A/D Converters |
| 中文描述： | 12位采樣的A / D轉(zhuǎn)換器 |
| 文件頁數(shù)： | 5/12頁 |
| 文件大?。?/td> | 171K |
| 代理商： | SP8505 |
47
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
SP85XX
Series.
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
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
SP85XX
Series
in a hold mode, and initiates a new conver-
sion.
The
SP85XX Series
will begin acquiring a new
sample just prior to the 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 on D
through D
and
D
through D
. Taking HBE HIGH then loads the 4
MSBs on D
3
through D
0
, with D
7
through D
4
being
forced LOW.
Analog Input Ranges
The
SP85XX Series
offers two standard bipolar
input ranges:
±
10V and
±
5V. If a
±
10V range is
required, the analog input signal should be con-
nected to pin 2. A signal requiring a
±
5V range
should be connected to pin 3. 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 SP85XX Series
The
SP85XX Series
can be easily interfaced to most
microprocessor-based and other digital systems. The
microprocessor may take full control of each conver-
sion, or the
SP85XX Series
may operate in a stand-
alone mode, controlled only by the R/C input. Full
control consists of initiating the conversion and read-
ing 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
FEATURES...
The
SP85XX Series
are specified at sampling
rates of 333kHz (
SP8503
), 200kHz (
SP8505
) or
100kHz (
SP8510
). Conversion times are factory
set for 2.70
μ
s, 4.7
μ
s and 9.7
μ
s maximum, re-
spectively, over temperature, and the high-
speed sampling input stage insures a total acqui-
sition and conversion time of 3
μ
s, 5
μ
s and 10
μ
s
maximum, respectively, over temperature. Pre-
cision, laser-trimmed scaling resistors provide
industry–standard input ranges of
±
5V or
±
10V.
The 28-pin
SP85XX Series
are available in
narrow body plastic DIP, and SOIC packages
and it operates from a single +5V supply.
The
SP85XX Series
are available in grades
specified over the 0
°
C to +70
°
C commercial
temperature ranges.
OPERATION
Basic Operation
Figure 1
shows the simple hookup circuit required
to operate the
SP85XX Series
in a
±
10V range in
the Convert Mode. A convert command arriving
on R/C puts the
SP85XX Series
in the HOLD
mode, and a conversion is started. This pulse must
be LOW for a minimum of 40ns. Because this
pulse establishes the sampling instant of the A/D,
it must 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
Figure 1. Basic
±
10V Operation
2
3
4
5
6
7
8
9
10
11
12
13
27
26
25
24
23
22
21
20
19
18
17
16
(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
V
REF
AGND
D11 (MSB)
D10
D9
D8
D7
D6
D5
D4
(D11
Out
Input
1
28
N.C.
N.C.
N.C.
N.C.
14
15
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| SP8505KN | 12-Bit Sampling A/D Converters |
| SP8505KS | 12-Bit Sampling A/D Converters |
| SP8510 | 12-Bit Sampling A/D Converters |
| SP8510KN | 12-Bit Sampling A/D Converters |
| SP8510KS | 12-Bit Sampling A/D Converters |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| SP8505KN | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:12-Bit Sampling A/D Converters |
| SP8505KS | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:12-Bit Sampling A/D Converters |
| SP8510 | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:12-Bit Sampling A/D Converters |
| SP8510KN | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:12-Bit Sampling A/D Converters |
| SP8510KS | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:12-Bit Sampling A/D Converters |
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