Moteur de recherche de fiches techniques de composants électroniques
  French  ▼
ALLDATASHEET.FR

X  

AD585SQ Fiches technique(PDF) 4 Page - Analog Devices

No de pièce AD585SQ
Description  High Speed, Precision Sample-and-Hold Amplifier
Download  6 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricant  AD [Analog Devices]
Site Internet  http://www.analog.com
Logo AD - Analog Devices

AD585SQ Fiches technique(HTML) 4 Page - Analog Devices

  AD585SQ Datasheet HTML 1Page - Analog Devices AD585SQ Datasheet HTML 2Page - Analog Devices AD585SQ Datasheet HTML 3Page - Analog Devices AD585SQ Datasheet HTML 4Page - Analog Devices AD585SQ Datasheet HTML 5Page - Analog Devices AD585SQ Datasheet HTML 6Page - Analog Devices  
Zoom Inzoom in Zoom Outzoom out
 4 / 6 page
background image
AD585
REV. A
–4–
SAMPLED DATA SYSTEMS
In sampled data systems there are a number of limiting factors
in digitizing high frequency signals accurately. Figure 9 shows
pictorially the sample-and-hold errors that are the limiting fac-
tors. In the following discussions of error sources the errors will
be divided into the following groups: 1. Sample-to-Hold Transi-
tion, 2. Hold Mode and 3. Hold-to-Sample Transition.
Figure 9. Pictorial Showing Various S/H Characteristics
SAMPLE-TO-HOLD TRANSITION
The aperture delay time is the time required for the sample-and-
hold amplifier to switch from sample to hold. Since this is effec-
tively a constant then it may be tuned out. If however, the
aperture delay time is not accounted for then errors of the mag-
nitude as shown in Figure 10 will result.
Figure 10. Aperture Delay Error vs. Frequency
To eliminate the aperture delay as an error source the sample-
to-hold command may be advanced with respect to the input
signal .
Once the aperture delay time has been eliminated as an error
source then the aperture jitter which is the variation in aperture
delay time from sample-to-sample remains. The aperture jitter is
a true error source and must be considered. The aperture jitter
is a result of noise within the switching network which modu-
lates the phase of the hold command and is manifested in the
variations in the value of the analog input that has been held.
The aperture error which results from this jitter is directly re-
lated to the dV/dT of the analog input.
The error due to aperture jitter is easily calculated as shown be-
low. The error calculation takes into account the desired accu-
racy corresponding to the resolution of the N-bit A/D converter.
f MAX =
2
–( N
+1)
π ( Aperture Jitter)
For an application with a 10-bit A/D converter with a 10 V full
scale to a 1/2 LSB error maximum.
f MAX =
2
–(10
+1)
π (0.5 × 10
–9
)
f MAX = 310.8 kHz.
For an application with a 12-bit A/D converter with a 10 V full
scale to a 1/2 LSB error maximum:
f MAX =
2
–(12
+1)
π (0.5 × 10
–9
)
f MAX = 77.7 kHz.
Figure 11 shows the entire range of errors induced by aperture
jitter with respect to the input signal frequency.
Figure 11. Aperture Jitter Error vs. Frequency
Sample-to-hold offset is caused by the transfer of charge to the
holding capacitor via the gate capacitance of the switch when
switching into hold. Since the gate capacitance couples the
switch control voltage applied to the gate on to the hold capaci-
tor, the resulting sample-to-hold offset is a function of the logic
level .
The logic inputs were designed for application flexibility and,
therefore, a wide range of logic thresholds. This was achieved by
using a differential input stage for HOLD and HOLD. Figure 1
shows the change in the sample-to-hold offset voltage based
upon an independently programmed reference voltage. Since
the input stage is a differential configuration, the offset voltage
is a function of the control voltage range around the pro-
grammed threshold voltage.
The sample-to-hold offset can be reduced by adding capacitance
to the internal 100 pF capacitor and by using HOLD instead of
HOLD. This may be easily accomplished by adding an external
capacitor between Pins 7 and 8. The sample-to-hold offset is
then governed by the relationship:
S/H Offset (V )
=
Charge pC
()
CH Total ( pF )


Numéro de pièce similaire - AD585SQ

FabricantNo de pièceFiches techniqueDescription
logo
Analog Devices
AD585 AD-AD585 Datasheet
526Kb / 6P
   High speed, Precision Sample-and-hold Amplifier
AD585JP-REEL AD-AD585JP-REEL Datasheet
342Kb / 6P
   High Speed, Precision Sample-and-Hold Amplifier
REV. A
AD585 AD-AD585_15 Datasheet
342Kb / 6P
   High Speed, Precision Sample-and-Hold Amplifier
REV. A
AD585 AD-AD585_17 Datasheet
526Kb / 6P
   High speed, Precision Sample-and-hold Amplifier
More results

Description similaire - AD585SQ

FabricantNo de pièceFiches techniqueDescription
logo
Analog Devices
AD585 AD-AD585_17 Datasheet
526Kb / 6P
   High speed, Precision Sample-and-hold Amplifier
logo
Intersil Corporation
HA5320 INTERSIL-HA5320 Datasheet
90Kb / 12P
   High Speed Precision Sample and Hold Amplifier
July 1994
logo
Analog Devices
AD585JP-REEL AD-AD585JP-REEL Datasheet
342Kb / 6P
   High Speed, Precision Sample-and-Hold Amplifier
REV. A
logo
Intersil Corporation
HA-5320883 INTERSIL-HA-5320883 Datasheet
309Kb / 11P
   High Speed Precision Sample and Hold Amplifier
logo
Analog Devices
AD585 AD-AD585_15 Datasheet
342Kb / 6P
   High Speed, Precision Sample-and-Hold Amplifier
REV. A
logo
Linear Technology
LF398S8 LINER-LF398S8 Datasheet
144Kb / 2P
   Precision Sample and Hold Amplifier?
LF198A LINER-LF198A Datasheet
1Mb / 16P
   Precision Sample and Hold Amplifier
logo
Analog Devices
AD346 AD-AD346 Datasheet
119Kb / 3P
   High Speed Sample-and-Hold Amplifier
REV. B
logo
Linear Technology
LF398S8 LINER-LF398S8_15 Datasheet
156Kb / 2P
   Precision Sample and Hold Amplifier
logo
Analog Devices
AD346 AD-AD346_15 Datasheet
1Mb / 4P
   HIGH SPEED SAMPLE AND HOLD AMPLIFIER
REV. A
More results


Html Pages

1 2 3 4 5 6


Fiches technique Télécharger

Go To PDF Page


Lien URL




Politique de confidentialité
ALLDATASHEET.FR
ALLDATASHEET vous a-t-il été utile ?  [ DONATE ] 

À propos de Alldatasheet   |   Publicité   |   Contactez-nous   |   Politique de confidentialité   |   Echange de liens   |   Fabricants
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com