Electronic Components Datasheet Search |
|
AD8295 Datasheet(PDF) 25 Page - Analog Devices |
|
AD8295 Datasheet(HTML) 25 Page - Analog Devices |
25 / 28 page AD8295 Rev. 0 | Page 25 of 2 8 DRIVING DIFFERENTIAL ADCs Figure 65 shows how to configure the AD8295 to drive a differ- ential ADC. The circuit shown uses very little board space and consumes little power. With the AD7690, this configuration gives excellent dc performance and a THD of 83 dB (10 kHz input). For applications that need better distortion performance, a dedicated ADC driver, such as the ADA4941-1 or ADA4922-1 is recommended. The 500 Ω resistors and the 2.2 nF capacitors form a low-pass, antialiasing filter at 144 kHz. The four elements of the filter also prevent the switching transients produced by a typical SAR converter from destabilizing the AD8295. The capacitors provide charge to the switched capacitor front end of the ADC, and the resistors shield the AD8295 from driving any sharp current changes. If the application requires a lower frequency anti- aliasing filter than the one shown, increasing the capacitor values produces much better distortion results than increasing the resistor values. The 500 Ω resistors also give the ADC protection against over- voltage. Because the AD8295 runs on wider supply voltages than a typical ADC, there is a possibility of overdriving some converters. This is not an issue with a PulSAR® ADC, such as the AD7690, because its input can handle a 130 mA overdrive, which is much higher than the short-circuit limit of the AD8295. However, other converters have less robust inputs and may benefit from the resistive protection. A1 OUT A1 R2 A2 +IN A2 –IN –IN –INPUT +INPUT RG +VS +7V 0.1µF –VS –7V OUT REF RG +IN IN– GND REF VDD IN+ 1 2 3 4 8 7 6 5 13 14 15 16 A1 IA A2 R1 20kΩ R2 20kΩ A2 OUT +5V + AD8295 ADR435 AD7690 A1 +IN 10µF +2.5V +OUT 500Ω 10kΩ 10kΩ 500Ω 2.2nF 2.2nF –OUT A1 R1 A1 –IN 12 11 10 9 0.1µF +5V 0.1µF 0.1µF +5V +7V 0.1µF Figure 65. Driving a Differential ADC |
Similar Part No. - AD8295 |
|
Similar Description - AD8295 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List 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 |