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參數(shù)資料
| 型號(hào)： | SP8505KN |
| 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)： | 8/12頁 |
| 文件大?。?/td> | 171K |
| 代理商： | SP8505KN |
50
The input resistance of the
SP85XX Series
is
6.3k
or 4.2K
(for the
±
10V and
±
5V ranges
respectively). To avoid introducing distortion, the
source resistance must be very low, or constant
with signal level. The output impedance provided
by most op amps is ideal. Pins 26 Digital Supply
Voltage (V
) and 27 Analog Supply Voltage
(V
) are brought out to separate pins to maximize
accuracy on the chip. They should be connected
together as close as possible to the unit. Pin 27 may
be slightly more sensitive than pin 26 to supply
variations, but to maintain maximum system accu-
racy, both should be well–isolated from digital
supplies with wide load variations.
To limit the effects of digital switching elsewhere
in a system on the analog performance of the
system, it often makes sense to run a separate +5V
supply conductor from the supply regulator to any
analog components requiring +5V, including the
SP85XX Series.
If the
SP85XX Series
traces
cannot be separated back to the power supply
terminals, and therefore share the same trace as the
logic supply currents, then a 10 Ohm isolating
resistor should be used between the board supply
and pin 24 (V
) and its bypass capacitors, to keep
V
glitch–free. The V
pins (26 and 27) should be
connected together and bypassed with a parallel
combination of a 6.8
μ
F Tantalum capacitor and a
0.1
μ
F ceramic capacitor located close to the con-
verter to obtain noise-free operation. (See
Figure
1
). Noise on the power supply lines can degrade
converter performance, especially noise and spikes
from a switching power supply. Appropriate sup-
plies or filters must be used.
The GND pins (5 and 16) are also separated internally,
and should be directly connected to a ground plane
under the converter. A ground plane is usually the best
solution for preserving dynamic performance and
reducing noise coupling into sensitive converter cir-
cuits. Where any compromises must be made, the
common return of the analog input signal should be
referenced to pin 5, AGND, on the
SP85XX Series,
which prevents any voltage drops that might occur in
the power supply common returns from appearing in
series with the input signal.
Coupling between analog input and digital lines should
be minimized by careful layout. For instance, if the
lines must cross, they should do so at right angles.
Parallel analog and digital lines should be separated
from each other by a pattern connected to common.
If external full scale and offset potentiometers are
used, the potentiometers and related resistors should
be located as close to the
SP85XX Series
as possible.
“Hot Socket” Precaution
Two separate +5V V
pins, 26 and 27, are used to
minimize noise caused by digital transients. If one
pin is powered and the other is not, the
SP85XX
Figure 4. Acquisition and Conversion Timing
R/C
BUSY
CMode
Acquisition
Conversion
Acquisition
Conversion
t
AP
Hold Time
t
C
t
DBC
t
B
SYMBOL/PARAMETER
t
DBC
BUSY delay from R/C
t
B
BUSY Low
MIN.
TYP.
80
2.5
4.5
9.5
13
150
2.47
4.47
9.47
MAX.
150
2.7
4.7
9.7
UNITS
ns
μ
s
μ
s
μ
s
ns
SP8503
SP8505
SP8510
t
AP
t
AP
t
C
Aperture Delay
Aperture Jitter
Conversion Time
ps, rms
2.70
4.70
9.70
μ
s
μ
s
μ
s
SP8503
SP8505
SP8510
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| 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 |
| SP8527 | Micropower Sampling 10-Bit A/D Converter |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 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 |
| SP852120 | 制造商:CELDUC 制造商全稱:celduc-relais 功能描述:Power Solid State Relay |
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