Electronic Components Datasheet Search |
|
LTC1061ACN Datasheet(PDF) 8 Page - Linear Technology |
|
LTC1061ACN Datasheet(HTML) 8 Page - Linear Technology |
8 / 16 page 8 LTC1061 ODES OF OPERATIO Figure 6. Measures Frequency Response of the Lowpass Butterworth Filter of Figure 3. 2. Secondary Modes: Mode 1b – It is derived from Mode 1. In Mode 1b, Figure 7, two additional resistors, R5 and R6, are added to attenuate the amount of voltage fed back from the lowpass output into the input of the SA (SB) switched capacitor summer. This allows the filter clock- to-center frequency ratio to be adjusted beyond 50:1 (or 100:1). Mode 1b still maintains the speed advantages of Mode 1. Figure 8 shows the 3 lowpass sections of the LTC1061 in cascade resulting in a Chebyshev lowpass filter. The side A of the IC is connected in Mode 1b to provide the first resonant frequency below the cutoff frequency of the filter. The practical ripple, obtained by using a non-A version of the LTC1061 and 1% standard resistor values, was 0.15dB. For this 6th order lowpass, the textbook Qs and center frequencies normalized to the ripple bandwidth are: Q1 = 0.55, fO1 = 0.71, Q2 = 1.03, FO2 = 0.969, Q3 = 3.4, FO3 = 1.17. The design was done with speed in mind. The higher (Q3, FO3) section was in Mode 1 and placed in the side B of the LTC1061. The remaining two center frequencies were then normalized with respect to the center frequency of side B; this changes the ratio of clock-to-cutoff frequency from 50:1 to 50 × 1.17 = 58.5:1. As shown in Figure 9, the maximum cutoff frequency is about 33kHz. The total wideband output noise is 220 µVRMS and the measured output DC offset voltage is 60mV. – + Σ ∫ ∫ AGND R1 N BP LP VIN 1061 F07 + – S R2 R3 R6 R5 fO = ; fn = fO; Q = HON1 (f → 0) = HON2 = – HOLP = ; HOBP = – ; (R5//R6) <5k fCLK 100(50) R2 R1 R3 R2 –R2/R1 R6/(R5 + R6) R3 R1 √ R6 R5 + R6 √ R6 R5 + R6 fCLK 2 f → () fIN (Hz) 10k –70 –60 –50 –40 –30 100k 1M 1061 F09 –20 –10 0 30k VS > ±5V TA = 25°C VIN = 1VRMS fCLK = 1.9MHz Figure 8. 6th Order Chebyshev, Lowpass Filter Using 3 Different Modes of Operation for Speed Optimization Figure 9. Amplitude Response of the 6th Order Chebyshev Lowpass Filter of Figure 8 Figure 7. Mode 1b: 2nd Order Filter Providing Notch, Bandpass, Lowpass fIN (Hz) 10k –70 –60 –50 –40 –30 100k 1M 1061 F06 –20 –10 0 20k 40k 200k VS ≥ ±5V TA = 25°C VIN = 1VRMS fCLK = 2MHz fC = 40kHz fCLK = 1MHz fC = 20kHz 20 19 18 17 16 15 14 13 12 11 1 2 3 4 5 6 7 8 9 10 R32 VOUT R11 VIN LTC1061 F08 LTC1061 R22 R12 R33 R23 R43 R31 R21 fCLK < 2MHz V – R13 V+ R51 R61 STANDARD 1% RESISTOR VALUES R11 = 35.7k R31 = 11.5k R51 = 5.49k R12 = 11k R61 = 2.87k R22 = 11k R23 = 10.5 R43 = 15.8k R32 = 36.5k R13 = 15.8k R33 = 13k R21 = 12.1k |
Similar Part No. - LTC1061ACN |
|
Similar Description - LTC1061ACN |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |