Moteur de recherche de fiches techniques de composants électroniques |
|
AD7171 Fiches technique(PDF) 3 Page - Analog Devices |
|
AD7171 Fiches technique(HTML) 3 Page - Analog Devices |
3 / 5 page Circuit Note CN-0188 Rev. B | Page 3 of 5 PCB Layout Considerations In any circuit where accuracy is crucial, it is important to consider the power supply and ground return layout on the board. The PCB should isolate the digital and analog sections as much as possible. This PCB was constructed in a four layer stack up with large area ground plane layers and power plane polygons. See the MT-031 Tutorial for more discussion on layout and grounding and the MT-101 Tutorial for information on decoupling techniques. The power supply to the AD7171 and ADuM5402 should be decoupled with 10 µF and 0.1 µF capacitors to properly suppress noise and reduce ripple. The capacitors should be placed as close to the device as possible with the 0.1 µF capacitor having a low ESR value. Ceramic capacitors are advised for all high frequency decoupling. Care should be taken in considering the isolation gap between the primary and secondary sides of the ADuM5402. The EVAL-CN0188-SDPZ board maximizes this distance by pulling back any polygons or components on the top layer and aligning them with the pins on the ADuM5402. Power supply lines should have as large a trace width as possible to provide low impedance paths and reduce glitch effects on the supply line. Clocks and other fast switching digital signals should be shielded from other parts of the board by digital ground. A complete design support package for this circuit note, including board layouts, can be found at http://www.analog.com/CN0188-DesignSupport. COMMON VARIATIONS There are a number of solutions available for high-side sensing of positive sources. IC solutions using current sense amplifiers, difference amplifiers, or a combination of these are available. “High-Side Current Sensing: Difference Amplifier vs, Current- Sense Amplifier,” Analog Dialogue, January 2008, describes the use of current sense and difference amplifiers. The article is available at www.analog.com/HighSide_CurrentSensing. The following URLs link to Analog Devices products which are useful in solving the current sense problem: Current sense amplifiers: www.analog.com/CurrentSenseAmps Difference amplifiers: www.analog.com/DifferenceAmps Instrumentation amplifiers: www.analog.com/InstrumentationAmps Figure3.AlternateGalvanicallyIsolatedNegativeRailCurrentSenseCircuitPoweredDirectlyfrom−48VSourceandADuM5402Isolator(AllConnectionsandDecouplingNotShown) SCLK PDRST DOUT VDD GND REFIN(+) AIN+ AIN− GNDISO +3.3VISO +3.3VISO GNDISO GNDISO ADR381 VIN VOUT GND LOAD SOURCE + −48V +2.5V + – VSHUNT RSHUNT ILOAD AD7171 R2 1kΩ 1% R4 1kΩ 1% 48.7kΩ, 1% U1 U1: ADA4051-1 REFIN(–) R3* − GNDISO R1* 1.24MΩ 1% VOA VIA VOB VIC VOC VIB VDD1 GND1 GNDISO GND1 GNDISO VISO +3.3V ADuM5402 *R1 ADDS 100mV OFFSET TO U1 OUTPUT AND ALLOWS MEASUREMENT AT ZERO LOAD CURRENT. IF R1 IS USED, REDUCE R3 T O 46.4kΩ TO MAINTAIN 2.5V FULL-SCALE |
Numéro de pièce similaire - AD7171 |
|
Description similaire - AD7171 |
|
|
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 |
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 |