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

X  

AD421BR Fiches technique(PDF) 5 Page - Analog Devices

No de pièce AD421BR
Description  Loop-Powered 4 mA to 20 mA DAC
Download  14 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricant  AD [Analog Devices]
Site Internet  http://www.analog.com
Logo AD - Analog Devices

AD421BR Fiches technique(HTML) 5 Page - Analog Devices

  AD421BR Datasheet HTML 1Page - Analog Devices AD421BR Datasheet HTML 2Page - Analog Devices AD421BR Datasheet HTML 3Page - Analog Devices AD421BR Datasheet HTML 4Page - Analog Devices AD421BR Datasheet HTML 5Page - Analog Devices AD421BR Datasheet HTML 6Page - Analog Devices AD421BR Datasheet HTML 7Page - Analog Devices AD421BR Datasheet HTML 8Page - Analog Devices AD421BR Datasheet HTML 9Page - Analog Devices Next Button
Zoom Inzoom in Zoom Outzoom out
 5 / 14 page
background image
AD421
–5–
REV. C
PIN FUNCTION DESCRIPTIONS
Pin
No.
Mnemonic
Function
1
REF OUT1
Reference Output 1. A precision +1.25 V reference is provided at this pin. It is intended as a precision ref-
erence source for other devices in the transmitter. REF OUT1 is a buffered output capable of providing up
to 0.5 mA to external circuitry. If REF OUT 1 is required to sink current, a resistive load of 100 k
Ω to COM
should be added. (See Reference section.)
2
REF OUT2
Reference Output 2. A precision +2.5 V reference is provided at this pin. To operate the AD421 with its
own reference, REF OUT2 should be connected to REF IN. It can also be used as a precision reference
source for other devices in the transmitter. REF OUT2 is a buffered output capable of providing up to
0.5 mA to external circuitry.
3
REF IN
Voltage Reference Input. The reference voltage for the AD421 is applied to this pin and it sets the span for
the AD421. The nominal reference voltage for the AD421 is +2.5 V for correct operation. This can be sup-
plied using an external reference source or by using the part’s own REF OUT2 voltage.
4
LV
Regulated Voltage Control Input. The LV input controls the loop gain of the servo amplifier to set VCC.
With LV connected to COM, the regulator voltage is set to 5 V nominal. If the LV input is connected through
0.01
µF to VCC, the regulated voltage is nominally 3.3 V. With LV connected to VCC the regulated voltage,
VCC, is 3 V nominal.
5
LATCH
DAC Latch Input. Logic Input. A rising edge of the LATCH signal loads the data from the serial input shift
register to the DAC latch and hence updates the output of the DAC. The number of clock cycles provided
between latch pulses determines whether the DAC is in alarm or normal current mode. (See Digital Inter-
face section.)
6
CLOCK
Data Clock Input. Data on the DATA input is clocked into the shift register on the rising edge of this
CLOCK input. The period of this clock equals the input serial data bit rate. This serial clock rate can be up
to 10 MHz. If 16 clock cycles are provided between LATCH pulses then the data on the DATA input is
accepted as normal 4–20 mA data. If more than 16 clock cycles are provided between LATCH pulses, the
data is assumed to be alarm current data (see Digital Interface section).
7
DATA
Data Input. The data to be loaded to the AD421 input shift register is applied to this input. Data should be
valid on the rising edge of the CLOCK input.
8
LOOP RTN
Loop Return Output. LOOP RTN is the return path for current flowing in the current loop.
9
COM
Common. This is the reference potential for the AD421 analog and digital inputs and outputs and for the
voltage regulator output.
10
C3
Filtering Capacitor. A low dielectric absorption capacitor ceramic capacitor should be connected between
this pin and COM for internal filtering of the switched current sources.
11
C2
Filtering Capacitor. See C3 description.
12
C1
Filtering Capacitor. See C3 description.
13
DRIVE
Output from the Voltage Regulator Loop. The DRIVE signal controls the external pass transistor to establish and
maintain the correct VCC level programmed by the LV inputs while providing the necessary bias as the loop cur-
rent is programmed from 4 mA to 20 mA.
14
COMP
Compensation Capacitor Input. A capacitor connected between COMP and DRIVE is required to stabilize
the feedback loop formed with the regulator op amp and the external pass transistor.
15
BOOST
This open collector pin sinks the necessary current from the loop so that the current flowing into BOOST
plus the current flowing into COM is equal to the programmed loop current.
16
VCC
Power Supply. VCC is the power supply input of the AD421 and it also provides the voltage regulator output,
driven by the external pass transistor. It is used both to bias the AD421 itself and to provide power for the
rest of the smart transmitter circuitry. The LV input determines the regulated voltage output to be either
3 V, 3.3 V or 5 V nominal. Alternatively, a separate power supply can be connected to this pin to power the
AD421. VCC should be decoupled to COM with a 2.2
µF capacitor.


Numéro de pièce similaire - AD421BR

FabricantNo de pièceFiches techniqueDescription
logo
Analog Devices
AD421BR AD-AD421BR Datasheet
171Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
AD421BRRL AD-AD421BRRL Datasheet
171Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
AD421BRZ AD-AD421BRZ Datasheet
171Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
AD421BRZRL AD-AD421BRZRL Datasheet
173Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
More results

Description similaire - AD421BR

FabricantNo de pièceFiches techniqueDescription
logo
Analog Devices
AD421 AD-AD421 Datasheet
171Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
AD421BRZRL AD-AD421BRZRL Datasheet
173Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
AD421 AD-AD421_15 Datasheet
173Kb / 14P
   Loop-Powered 4 mA to 20 mA DAC
REV. C
AD5421 AD-AD5421_13 Datasheet
726Kb / 36P
   16-Bit, Serial Input, Loop-Powered, 4 mA to 20 mA DAC
Rev. F
AD5421 AD-AD5421_11 Datasheet
757Kb / 32P
   16-Bit, Serial Input, Loop-Powered, 4 mA to 20 mA DAC
REV. 0
UG-250 AD-UG-250 Datasheet
562Kb / 12P
   Evaluation Board for 16-Bit, Serial Input, Loop-Powered 4 mA to 20 mA DAC
REV. A
AD693 AD-AD693_15 Datasheet
499Kb / 12P
   Loop-Powered 4-20 mA Sensor Transmitter
REV. A
CN-0267 AD-CN-0267 Datasheet
407Kb / 8P
   Complete 4 mA to 20 mA Loop Powered Field Instrument with HART Interface
REV. A
AD693BQ AD-AD693BQ Datasheet
462Kb / 12P
   Loop-Powered 4??0 mA Sensor Transmitter
REV. A
AD420 AD-AD420 Datasheet
144Kb / 11P
   Serial Input 16-Bit 4 mA-20 mA, 0 mA-20 mA DAC
REV. F
More results


Html Pages

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


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