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

X  

AD7862AN-3 Fiches technique(PDF) 10 Page - Analog Devices

No de pièce AD7862AN-3
Description  Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
Download  16 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricant  AD [Analog Devices]
Site Internet  http://www.analog.com
Logo AD - Analog Devices

AD7862AN-3 Fiches technique(HTML) 10 Page - Analog Devices

Back Button AD7862AN-3 Datasheet HTML 6Page - Analog Devices AD7862AN-3 Datasheet HTML 7Page - Analog Devices AD7862AN-3 Datasheet HTML 8Page - Analog Devices AD7862AN-3 Datasheet HTML 9Page - Analog Devices AD7862AN-3 Datasheet HTML 10Page - Analog Devices AD7862AN-3 Datasheet HTML 11Page - Analog Devices AD7862AN-3 Datasheet HTML 12Page - Analog Devices AD7862AN-3 Datasheet HTML 13Page - Analog Devices AD7862AN-3 Datasheet HTML 14Page - Analog Devices Next Button
Zoom Inzoom in Zoom Outzoom out
 10 / 16 page
background image
AD7862
–10–
REV. 0
respectively). The third and fourth read pulses, after the second
conversion and A0 high, access the result from Channel B (VB1
and VB2 respectively). Data is read from the part via a 12-bit
parallel data bus with standard CS and RD signals. This data
read operation consists of negative going pulse on the CS pin
combined with a negative going pulse on the RD pin; this repeated
twice will access the two 12-bit results. For the fastest throughput
rate (with an internal clock of 3.7 MHz), the read operation will
take 100 ns. The read operation must be complete at least 300 ns
before the falling edge of the next CONVST, and this gives a total
time of 4
µs for the full throughput time (equivalent to 250 kHz).
This mode of operation should be used for high sampling
applications.
Mode 2 Operation (Auto Sleep After Conversion)
The timing diagram in Figure 6 is for optimum performance in
Operating Mode 2 where the part automatically goes into sleep
mode once BUSY goes low after conversion and “wakes-up”
before the next conversion takes place. This is achieved by keeping
CONVST
low at the end of the second conversion, whereas it
was high at the end of the second conversion for Mode 1 opera-
tion. The operation shown in Figure 6 shows how to access data
from both Channels A and B followed by the Auto Sleep mode.
One can also setup the timing to access data from Channel A
only or Channel B only (see Read Options section on previous
page) and then go into Auto-Sleep mode. The rising edge of
CONVST
“wakes-up” the part. This wake-up time is 2.5
µs
when using an external reference and 5 ms when using the
internal reference at which point the Track/Hold amplifier’s go
into their hold mode, provided the CONVST has gone low. The
conversion takes 3.6
µs after this, giving a total of 6 µs (external
reference, 5.0035 ms for internal reference) from the rising edge
of CONVST to the conversion being complete, which is
indicated by the BUSY going low. Note that since the wake-up
time from the rising edge of CONVST is 2.5
µs, if the CONVST
pulse width is greater than 2.5
µs, the conversion will take more
than the 6
µs (2.5 µs wake-up time + 3.6 µs conversion time)
shown in the diagram from the rising edge of CONVST. This is
because the track/hold amplifiers go into their hold mode on
the falling edge of CONVST, and the conversion will not be
complete for a further 3.6
µs. In this case the BUSY will be the
best indicator for when the conversion is complete. Even though
the part is in sleep mode, data can still be read from the part.
The read operation is identical to Mode 1 operation and must
also be complete at least 300 ns before the falling edge of the
next CONVST to allow the track/hold amplifiers to have enough
time to settle. This mode is very useful when the part is convert-
ing at a slow rate, as the power consumption will be significantly
reduced from that of Mode 1 operation.
DYNAMIC SPECIFICATIONS
The AD7862 is specified and 100% tested for dynamic perfor-
mance specifications as well as traditional dc specifications such
as Integral and Differential Nonlinearity. These ac specifications
are required for the signal processing applications such as phased
array sonar, adaptive filters and spectrum analysis. These applica-
tions require information on the ADC’s effect on the spectral
content of the input signal. Hence, the parameters for which the
AD7862 is specified include SNR, harmonic distortion, inter-
modulation distortion and peak harmonics. These terms are
discussed in more detail in the following sections.
Signal-to-Noise Ratio (SNR)
SNR is the measured signal-to-noise ratio at the output of the
ADC. The signal is the rms magnitude of the fundamental.
Noise is the rms sum of all the nonfundamental signals up to
half the sampling frequency (fS/2) excluding dc. SNR is depen-
dent upon the number of quantization levels used in the
digitization process; the more levels, the smaller the quantiza-
tion noise. The theoretical signal to noise ratio for a sine wave
input is given by
SNR = (6.02N + 1.76) dB
(1)
where N is the number of bits.
Thus for an ideal 12-bit converter, SNR = 74 dB.
VA1
VA2
VB1
VB2
t
3
t
CONV = 3.6µs
CONVST
BUSY
A0
CS
RD
DATA
300ns
400ns
t
3
2.5µs*/5ms**
WAKE-UP
TIME
t
CONV = 3.5µs
**WHEN USING AN EXTERNAL REFERENCE, WAKE-UP TIME = 2.5µs
**WHEN USING AN INTERNAL REFERENCE, WAKE-UP TIME = 5ms
Figure 6. Mode 2 Timing Where Automatic Sleep Function Is Initiated


Numéro de pièce similaire - AD7862AN-3

FabricantNo de pièceFiches techniqueDescription
logo
Analog Devices
AD7862AN-3 AD-AD7862AN-3 Datasheet
417Kb / 16P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
REV. 0
AD7862AN-3 AD-AD7862AN-3 Datasheet
331Kb / 16P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
REV. 0
AD7862AN-3 AD-AD7862AN-3 Datasheet
331Kb / 16P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
REV. 0
AD7862AN-3 AD-AD7862AN-3 Datasheet
417Kb / 16P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
REV. 0
AD7862AN-3 AD-AD7862AN-3 Datasheet
449Kb / 17P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
More results

Description similaire - AD7862AN-3

FabricantNo de pièceFiches techniqueDescription
logo
Analog Devices
AD7862ANZ-10 AD-AD7862ANZ-10 Datasheet
331Kb / 16P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
REV. 0
AD7862ARSZ-10 AD-AD7862ARSZ-10 Datasheet
417Kb / 16P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
REV. 0
AD7862ARZ-10 AD-AD7862ARZ-10 Datasheet
417Kb / 16P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
REV. 0
AD7862 AD-AD7862_17 Datasheet
449Kb / 17P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
AD7862ARSZ-2 AD-AD7862ARSZ-2 Datasheet
331Kb / 16P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
REV. 0
AD7862 AD-AD7862_15 Datasheet
417Kb / 16P
   Simultaneous Sampling Dual 250 kSPS 12-Bit ADC
REV. 0
AD7656YSTZ AD-AD7656YSTZ Datasheet
588Kb / 32P
   250 kSPS, 6-Channel, Simultaneous Sampling, Bipolar 16-/14-/12-Bit ADC
Rev. D
AD7656 AD-AD7656 Datasheet
588Kb / 32P
   250 kSPS, 6-Channel, Simultaneous Sampling, Bipolar 16-/14-/12-Bit ADC
Rev. D
AD7863 AD-AD7863 Datasheet
1Mb / 24P
   Simultaneous Sampling Dual 175 kSPS 14-Bit ADC
REV. B
AD7658 AD-AD7658 Datasheet
313Kb / 25P
   250 kSPS, 6-Channel,Simultaneous Sampling, Bipolar 12/14/16-Bit ADC
Rev. PrI
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16


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