Motore di ricerca datesheet componenti elettronici
  Italian  ▼
ALLDATASHEETIT.COM

X  

AD7888BR-REEL Scheda tecnica(PDF) 8 Page - Analog Devices

Il numero della parte AD7888BR-REEL
Spiegazioni elettronici  2.7 V to 5.25 V, Micropower, 8-Channel, 125 kSPS, 12-Bit ADC in 16-Lead TSSOP
Download  17 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Produttore elettronici  AD [Analog Devices]
Homepage  http://www.analog.com
Logo AD - Analog Devices

AD7888BR-REEL Scheda tecnica(HTML) 8 Page - Analog Devices

Back Button AD7888BR-REEL Datasheet HTML 4Page - Analog Devices AD7888BR-REEL Datasheet HTML 5Page - Analog Devices AD7888BR-REEL Datasheet HTML 6Page - Analog Devices AD7888BR-REEL Datasheet HTML 7Page - Analog Devices AD7888BR-REEL Datasheet HTML 8Page - Analog Devices AD7888BR-REEL Datasheet HTML 9Page - Analog Devices AD7888BR-REEL Datasheet HTML 10Page - Analog Devices AD7888BR-REEL Datasheet HTML 11Page - Analog Devices AD7888BR-REEL Datasheet HTML 12Page - Analog Devices Next Button
Zoom Inzoom in Zoom Outzoom out
 8 / 17 page
background image
AD7888
–8–
Figure 4 shows the typical power supply rejection ratio vs.
frequency for the part. The power supply rejection ratio is defined
as the ratio of the power in the ADC output at frequency f
to the power of a full-scale sine wave applied to the ADC of
frequency fs:
PSRR (dB) = 10 log (Pf/Pfs)
Pf = Power at frequency f in ADC output, Pfs = power at fre-
quency fs in ADC full scale input. Here a 100 mV peak-to-peak
sine wave is coupled onto the VDD supply. Both the 2.7 V and
5.5 V supply performances are shown.
INPUT FREQUENCY – kHz
–93
2.65
64.15
12.85
33.65
VDD = 5.5V/2.7V
100mV p-p SINE WAVE ON VDD
REFIN = 2.488V EXT REFERENCE
23.15
–91
–89
–87
–85
–83
–81
–79
–77
–75
43.85
54.35
Figure 4. PSRR vs. Frequency
CIRCUIT INFORMATION
The AD7888 is a fast, low power, 12-bit, single supply, 8-channel
A/D converter. The part can be operated from 3 V (2.7 V to
3.6 V) supply or from 5 V (4.75 V to 5.25 V) supply. When
operated from either a 5 V supply or a 3 V supply, the AD7888
is capable of throughput rates of 125 kSPS when provided with
a 2 MHz clock.
The AD7888 provides the user with an 8-channel multiplexer,
on-chip track/hold, A/D converter, reference and serial interface
housed in a tiny 16-lead TSSOP package, which offers the user
considerable space saving advantages over alternative solutions.
The serial clock input accesses data from the part and also
provides the clock source for the successive-approximation
A/D converter. The analog input range is 0 to VREF (where
the externally-applied VREF can be between 1.2 V and VDD).
The 8-channel multiplexer is controlled by the part’s Control
Register. This Control Register also allows the user to power-off
the internal reference and to determine the Modes of Operation.
CONVERTER OPERATION
The AD7888 is a successive-approximation analog-to-digital
converter based around a charge redistribution DAC. Figures 5
and 6 show simplified schematics of the ADC. Figure 5 shows
the ADC during its acquisition phase. SW2 is closed and SW1 is
in Position A, the comparator is held in a balanced condition
and the sampling capacitor acquires the signal on AIN.
CHARGE
REDISTRIBUTION
DAC
(REF IN/REF OUT)/2
SAMPLING
CAPACITOR
COMPARATOR
CONTROL
LOGIC
ACQUISITION
PHASE
SW1
A
SW2
AGND
B
AIN
Figure 5. ADC Acquisition Phase
When the ADC starts a conversion, (see Figure 6), SW2 will open
and SW1 will move to Position B causing the comparator to
become unbalanced. The control logic and the charge redistribu-
tion DAC are used to add and subtract fixed amounts of charge
from the sampling capacitor to bring the comparator back into a
balanced condition. When the comparator is rebalanced, the
conversion is complete. The control logic generates the ADC
output code. Figure 7 shows the ADC transfer function.
CONVERSION
PHASE
CHARGE
REDISTRIBUTION
DAC
(REF IN/REF OUT)/2
SAMPLING
CAPACITOR
COMPARATOR
CONTROL
LOGIC
SW1
A
SW2
AGND
B
VIN
Figure 6. ADC Conversion Phase
ADC TRANSFER FUNCTION
The output coding of the AD7888 is straight binary. The
designed code transitions occur at successive integer LSB
values (i.e., 1 LSB, 2 LSBs, etc.). The LSB size is = VREF/
4096. The ideal transfer characteristic for the AD7888 is
shown in Figure 7 below.
0V
ANALOG INPUT
111...000
011...111
0.5LSB
+VREF – 1.5LSB
1LSB = VREF/4096
111...111
111...110
000...010
000...001
000...000
Figure 7. Transfer Characteristic
REV. C


Codice articolo simile - AD7888BR-REEL

Produttore elettroniciIl numero della parteScheda tecnicaSpiegazioni elettronici
logo
Analog Devices
AD7888BR-REEL AD-AD7888BR-REEL Datasheet
245Kb / 18P
   Micropower, 8-Channel, 125 kSPS, 12-Bit ADC in 16-Lead TSSOP
AD7888BR-REEL7 AD-AD7888BR-REEL7 Datasheet
245Kb / 18P
   Micropower, 8-Channel, 125 kSPS, 12-Bit ADC in 16-Lead TSSOP
More results

Descrizione simile - AD7888BR-REEL

Produttore elettroniciIl numero della parteScheda tecnicaSpiegazioni elettronici
logo
Analog Devices
AD7888 AD-AD7888_10 Datasheet
197Kb / 17P
   2.7 V to 5.25 V, Micropower, 8-Channel, 125 kSPS, 12-Bit ADC in 16-Lead TSSOP
REV. C
AD7888 AD-AD7888 Datasheet
175Kb / 16P
   2.7V to 5.25 V Micropower 8-Channel 125 kSPS 12-Bit ADC in 16-Lead TSSOP
REV. B
AD7887 AD-AD7887 Datasheet
133Kb / 16P
   2.7 V to 5.25 V, Micropower, 2-Channel, 125 kSPS, 12-Bit ADC in 8-Lead uSOIC
REV. B
AD7887 AD-AD7887_09 Datasheet
444Kb / 24P
   2.7 V to 5.25 V, Micropower, 2-Channel, 125 kSPS, 12-Bit ADC in 8-Lead MSOP
REV. D
AD7887 AD-AD7887_15 Datasheet
392Kb / 24P
   2.7 V to 5.25 V, Micropower, 2-Channel, 125 kSPS, 12-Bit ADC in 8-Lead MSOP
Rev. E
AD7888 AD-AD7888_17 Datasheet
245Kb / 18P
   Micropower, 8-Channel, 125 kSPS, 12-Bit ADC in 16-Lead TSSOP
AD7887 AD-AD7887_17 Datasheet
465Kb / 25P
   Micropower, 2-Channel, 125 kSPS, 12-Bit ADC in 8-Lead MSOP
AD7923 AD-AD7923_17 Datasheet
423Kb / 25P
   4-Channel, 200 kSPS 12-Bit ADC Sequencer in 16-Lead TSSOP
AD7927 AD-AD7927_17 Datasheet
485Kb / 29P
   8-Channel, 200 kSPS, 12-Bit ADC Sequencer in 20-Lead TSSOP
AD7923 AD-AD7923_11 Datasheet
380Kb / 24P
   4-Channel, 200 kSPS 12-Bit ADC with Sequencer in 16-Lead TSSOP
REV. C
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17


Scheda tecnica Scarica

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEETIT.COM
Lei ha avuto il aiuto da alldatasheet?  [ DONATE ] 

Di alldatasheet   |   Richest di pubblicita   |   contatti   |   Privacy Policy   |   scambio Link   |   Ricerca produttore
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