 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LTC2495 Datasheet(PDF) 26 Page - Linear Technology |
|
||||||||||||||||||||||||||||||
LTC2495 Datasheet(HTML) 26 Page - Linear Technology |
|
|
26 / 32 page  LTC2495 26 2495f Figure 17. INL vs Differential Input Voltage and Reference Source Resistance for CREF > 1µF Figure 19. Input Normal Mode Rejection, Internal Oscillator and 60Hz Rejection Mode Figure 18. Input Normal Mode Rejection, Internal Oscillator and 50Hz Rejection Mode Normal Mode Rejection and Antialiasing One of the advantages delta-sigma ADCs offer over conventional ADCs is on-chip digital filtering. Combined with a large oversample ratio, the LTC2495 significantly simplifies antialiasing filter requirements. Additionally, the input current cancellation feature allows external low pass filtering without degrading the DC performance of the device. The SINC4 digital filter provides excellent normal mode rejection at all frequencies except DC and integer multiples of the modulator sampling frequency (fS) (see Figures 18 and 19). The modulator sampling frequency is fS = 15,360Hz while operating with its internal oscillator and fS = fEOSC/20 when operating with an external oscillator of frequency fEOSC. When using the internal oscillator, the LTC2495 is designed to reject line frequencies. As shown in Figure 20, rejec- tion nulls occur at multiples of frequency fN, where fN is determined by the input control bits FA and FB (fN = 50Hz or 60Hz or 55Hz for simultaneous rejection). Multiples of the modulator sampling rate (fS = fN • 256) only reject noise to 15dB (see Figure 21); if noise sources are present at these frequencies antialiasing will reduce their effects. The user can expect to achieve this level of performance using the internal oscillator, as shown in Figures 22, 23, and 24. Measured values of normal mode rejection are APPLICATIONS INFORMATION Figure 15. +FS Error vs RSOURCE at VREF (Large CREF) Figure 16. –FS Error vs RSOURCE at VREF (Large CREF) RSOURCE (Ω) 0 300 400 500 800 2495 F15 200 100 0 200 400 600 1000 VCC = 5V VREF = 5V VIN + = 3.75V VIN – = 1.25V FO = GND TA = 25°C CREF = 1µF, 10µF CREF = 0.1µF CREF = 0.01µF RSOURCE (Ω) 0 –200 –100 0 800 2495 F16 –300 –400 –500 200 400 600 1000 VCC = 5V VREF = 5V VIN + = 1.25V VIN – = 3.75V FO = GND TA = 25°C CREF = 1µF, 10µF CREF = 0.1µF CREF = 0.01µF VIN/VREF – 0.5 2 6 10 0.3 2495 F17 –2 –6 0 4 8 –4 –8 –10 – 0.3 – 0.1 0.1 0.5 VCC = 5V VREF = 5V VIN(CM) = 2.5V TA = 25°C CREF = 10µF R = 1k R = 100 Ω R = 500 Ω DIFFERENTIAL INPUT SIGNAL FREQUENCY (Hz) 0fS 2fS 3fS 4fS 5fS 6fS 7fS 8fS 9fS10fS11fS12fS 2495 F18 0 –10 –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 DIFFERENTIAL INPUT SIGNAL FREQUENCY (Hz) 0fS 2495 F19 0 –10 –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 2fS 3fS 4fS 5fS 6fS 7fS 8fS 9fS 10fS |
Similar Part No. - LTC2495 |
|
Similar Description - LTC2495 |
|
|
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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
