전자부품 데이터시트 검색엔진
  Korean  ▼
ALLDATASHEET.CO.KR

X  

AD7865AS-3 데이터시트(PDF) 10 Page - Analog Devices

부품명 AD7865AS-3
상세설명  Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
Download  19 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
제조업체  AD [Analog Devices]
홈페이지  http://www.analog.com
Logo AD - Analog Devices

AD7865AS-3 데이터시트(HTML) 10 Page - Analog Devices

Back Button AD7865AS-3 Datasheet HTML 6Page - Analog Devices AD7865AS-3 Datasheet HTML 7Page - Analog Devices AD7865AS-3 Datasheet HTML 8Page - Analog Devices AD7865AS-3 Datasheet HTML 9Page - Analog Devices AD7865AS-3 Datasheet HTML 10Page - Analog Devices AD7865AS-3 Datasheet HTML 11Page - Analog Devices AD7865AS-3 Datasheet HTML 12Page - Analog Devices AD7865AS-3 Datasheet HTML 13Page - Analog Devices AD7865AS-3 Datasheet HTML 14Page - Analog Devices Next Button
Zoom Inzoom in Zoom Outzoom out
 10 / 19 page
background image
REV. B
AD7865
–10–
CIRCUIT DESCRIPTION
Analog Input Section
The AD7865 is offered as three part types, the AD7865-1 where
each input can be configured for
±10 V or a ±5 V input voltage
range, the AD7865-3 which handles input voltage range
±2.5 V
and the AD7865-2 which has an input voltage range of 0 V to
2.5 V or 0 V to 5 V. The amount of current flowing into the
analog input will depend on the analog input range and the analog
input voltage. The maximum current flows when negative full
scale is applied.
AD7865-1
Figure 2 shows the analog input section of the AD7865-1. Each
input can be configured for
±5 V or ±10 V operation on the
AD7865-1. For
±5 V operation, the V
INxA and VINxB inputs are
tied together and the input voltage is applied to both. For
±10 V
operation, the VINxB input is tied to AGND and the input volt-
age is applied to the VINxA input. The VINxA and VINxB inputs are
symmetrical and fully interchangeable. Thus for ease of PCB
layout on the
±10 V range, the input voltage may be applied to
the VINxB input while the VINxA input is tied to AGND.
AD7865-1
VINxA
TRACK/
HOLD
TO ADC
REFERENCE
CIRCUITRY
TO INTERNAL
COMPARATOR
R4
R1
R2
6k
2.5V
REFERENCE
R3
GND
VINxB
VREF
Figure 2. AD7865-1 Analog Input Structure
For the AD7865-1, R1 = 4 k
Ω, R2 = 16 kΩ, R3 = 16 kΩ and R4
= 8 k
Ω. The resistor input stage is followed by the high input
impedance stage of the track/hold amplifier.
The designed code transitions take place midway between suc-
cessive integer LSB values (i.e., 1/2 LSB, 3/2 LSBs, 5/2 LSBs
etc.) LSB size is given by the formula, 1 LSB = FSR/16384. For
the
±5 V range, 1 LSB = 10 V/16384 = 610.4 µV. For the ±10 V
range, 1 LSB = 20 V/16384 = 1.22 mV. Output coding is twos
complement binary with 1 LSB = FSR/16384. The ideal input/
output transfer function for the AD7865-1 is shown in Table I.
Table I. Ideal Input/Output Code Table for the AD7865-1
Analog Input
1
Digital Output Code Transition
+FSR/2 – 3/2 LSB
2
011 . . . 110 to 011 . . . 111
+FSR/2 – 5/2 LSB
011 . . . 101 to 011 . . . 110
+FSR/2 – 7/2 LSB
011 . . . 100 to 011 . . . 101
AGND + 3/2 LSB
000 . . . 001 to 000 . . . 010
AGND + 1/2 LSB
000 . . . 000 to 000 . . . 001
AGND – 1/2 LSB
111 . . . 111 to 000 . . . 000
AGND – 3/2 LSB
111 . . . 110 to 111 . . . 111
–FSR/2 + 5/2 LSB
100 . . . 010 to 100 . . . 011
–FSR/2 + 3/2 LSB
100 . . . 001 to 100 . . . 010
–FSR/2 + 1/2 LSB
100 . . . 000 to 100 . . . 001
NOTES
1FSR is full-scale range and is 20 V for the
±10 V range and 10 V for the ±5 V
range, with VREF = 2.5 V.
21 LSB = FSR/16384 = 1.22 mV (
±10 V—AD7865-1) and 610.4 mV (±5 V—
AD7865-1) with VREF = 2.5 V.
AD7865-2
Figure 3 shows the analog input section of the AD7865-2. Each
input can be configured for 0 V to 5 V operation or 0 V to 2.5 V
operation. For the 0 V to 5 V operation, the VINxB input is tied
to AGND and the input voltage is applied to VINxA input. For
0 V to 2.5 V operation, the VINxA and VINxB inputs are tied together
and the input voltage is applied to both. The VINxA and VINxB
inputs are symmetrical and fully interchangeable. Thus for ease
of PCB layout on the 0 V to 5 V range the input voltage may be
applied to the VINxB input while the VINxA input is tied to AGND.
For the AD7865-2, R1 = 4 k
Ω and R2 = 4 kΩ. Once again,
the designed code transitions occur on successive integer LSB
values. Output coding is straight (natural) binary with 1 LSB
= FSR/16384 = 2.5 V/16384 = 0.153 mV, and 5 V/16384 =
0.305 mV, for 0 V to 2.5 V and 0 V to 5 V options respectively.
Table II shows the ideal input and output transfer function
for the AD7865-2.
AD7865-2
VINxA
TRACK/
HOLD
TO ADC
REFERENCE
CIRCUITRY
TO INTERNAL
COMPARATOR
R1
6k
2.5V
REFERENCE
R2
VINxB
VREF
Figure 3. AD7865-2 Analog Input Structure
Table II. Ideal Input/Output Code Table for the AD7865-2
Analog Input
1
Digital Output Code Transition
+FSR/2 – 3/2 LSB
2
111 . . . 110 to 111 . . . 111
+FSR/2 – 5/2 LSB
111 . . . 101 to 111 . . . 110
+FSR/2 – 7/2 LSB
111 . . . 100 to 111 . . . 101
AGND + 5/2 LSB
000 . . . 010 to 000 . . . 011
AGND + 3/2 LSB
000 . . . 001 to 000 . . . 010
AGND – 1/2 LSB
000 . . . 000 to 000 . . . 001
NOTES
1FSR is full-scale range and is 0 V to 2.5 V and 0 V to 5 V for AD7865-2 with
VREF = 2.5 V.
21 LSB = FSR/16384 and is 0.153 mV (0 V to 2.5 V) and 0.305 mV (0 V to 5 V)
for AD7865-2) with VREF = 2.5 V.


유사한 부품 번호 - AD7865AS-3

제조업체부품명데이터시트상세설명
logo
Analog Devices
AD7865AS-3 AD-AD7865AS-3 Datasheet
195Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. A
AD7865AS-3 AD-AD7865AS-3 Datasheet
211Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
AD7865AS-3 AD-AD7865AS-3 Datasheet
197Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
AD7865AS-3 AD-AD7865AS-3 Datasheet
197Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
AD7865AS-3 AD-AD7865AS-3 Datasheet
197Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
More results

유사한 설명 - AD7865AS-3

제조업체부품명데이터시트상세설명
logo
Analog Devices
AD7865ASZ-1 AD-AD7865ASZ-1 Datasheet
211Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
AD7865ASZ-3 AD-AD7865ASZ-3 Datasheet
197Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
AD7865ASZ AD-AD7865ASZ Datasheet
197Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
AD7865BSZ-1 AD-AD7865BSZ-1 Datasheet
211Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
AD7865ASZ-3 AD-AD7865ASZ-3 Datasheet
211Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
AD7865 AD-AD7865_17 Datasheet
242Kb / 20P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
AD7865 AD-AD7865 Datasheet
195Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. A
AD7865ASZ-2 AD-AD7865ASZ-2 Datasheet
197Kb / 19P
   Four-Channel, Simultaneous Sampling, Fast, 14-Bit ADC
REV. B
logo
Linear Technology
LTC1408 LINER-LTC1408 Datasheet
496Kb / 20P
   Channel, 14-Bit, 600ksps Simultaneous Sampling ADC with Shutdown
LTC2351-14 LINER-LTC2351-14 Datasheet
289Kb / 20P
   Channel, 14-Bit, 1.5Msps Simultaneous Sampling ADC with Shutdown
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19


데이터시트 다운로드

Go To PDF Page


링크 URL




개인정보취급방침
ALLDATASHEET.CO.KR
ALLDATASHEET 가 귀하에 도움이 되셨나요?  [ DONATE ] 

Alldatasheet는?   |   광고문의   |   운영자에게 연락하기   |   개인정보취급방침   |   링크교환   |   제조사별 검색
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