參數(shù)資料
型號: SP8538AN
英文描述: Micropower Sampling 12-Bit A/D Converter
中文描述: 微采樣12位A / D轉(zhuǎn)換器
文件頁數(shù): 7/12頁
文件大?。?/td> 305K
代理商: SP8538AN
SP8538DS/01
SP8538 Micropower Sampling 12-Bit A/D Converter
7
Copyright 1999 Sipex Corporation
by the differential sampling of the
SP8538
.
Layout Considerations
To preserve the high resolution and linearity of
the
SP8538
attention must be given to circuit
board layout, ground impedance and bypassing.
A circuit board layout which includes separate
analog and digital ground planes will prevent
the coupling of noise into sensitive converter
circuits and will help to preserve the dynamic
performance of the device. In single ended
mode, the analog input signal should be
referenced to the ground pin of the converter.
This prevents any voltage drops
that occur in
the power supply's common return from
appearing in series with the input signal.
In full differential mode, the high and low side
board traces should run close to each other, with
the same layout. This will insure that any noise
coupling will be common mode, and cancelled
by the converters (patent pending) full differential
architecture.
If separate analog and digital ground planes are
not possible, care should be used to prevent
coupling between analog and digital signals. If
analog and digital lines must cross, they should
CS
CLK
DIN
DOUT
CS
CLK
DIN
DOUT
X
X
POWER UP
SAMPLE
CONVERT
1
4
10
16
X
START O/S
S/D LSBFN
HI-Z
“0”
D1
20
D0 D1
POWER DOWN
28
X
D11
HI-Z
X
LSB FIRST CONVERSION
D11
X
X
POWER UP
SAMPLE
CONVERT
1
4
10
16
X
START O/S
S/D MSBF
HI-Z
“0”
D1 D0
POWER DOWN
X
HI-Z
X
D11
17
MSB FIRST CONVERSION
do so at right angles. Parallel analog and digital
lines should be separated by a circuit board trace
which is connected to common.
The
SP8538
VCC pin is also the reference pin
for the device. This means that noise on the VCC
pin will be proportionally represented as noise
in the converters output data. A noise signal of
1.22mV (at a 5V supply) will produce 1 LSB of
error in the output data. The VCC pin should be
bypassed to the ground pin with a parallel
combination of a 6.8
μ
F tantalum and a 0.1
μ
F
ceramic capacitor. To maintain maximum
system accuracy, the supply connected to the
VCC pin should be well isolated from digital
supplies and wide load variations. A separate
conductor from the supply regulator to the A/D
converter will limit the effects of digital switching
elsewhere in the system. Power supply noise can
degrade the converters performance. Especially
corrupting are noise and spikes from a switching
power supply.
To avoid introducing distortion when driving the
A/D converter input, the input signal source
should be able to charge the
SP8538's
equivalent 20 pF of input capacitance from zero
volts to the signal level in 1.5 clock periods.
SP8538 Timing Diagram
相關(guān)PDF資料
PDF描述
SP8538AS Micropower Sampling 12-Bit A/D Converter
SP8538BN Micropower Sampling 12-Bit A/D Converter
SP8538BS Micropower Sampling 12-Bit A/D Converter
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SP8538KS Micropower Sampling 12-Bit A/D Converter
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SP8538AS 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Micropower Sampling 12-Bit A/D Converter
SP8538BN 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Micropower Sampling 12-Bit A/D Converter
SP8538BS 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Micropower Sampling 12-Bit A/D Converter
SP8538JN 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Micropower Sampling 12-Bit A/D Converter
SP8538JS 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:Micropower Sampling 12-Bit A/D Converter