công cụ tìm kiếm bảng dữ liệu linh kiện điện tử |
|
AD8682 bảng dữ liệu(PDF) 11 Page - Analog Devices |
|
AD8682 bảng dữ liệu(HTML) 11 Page - Analog Devices |
11 / 16 page AD8682/AD8684 Rev. A | Page 11 of 16 PROGRAMMABLE STATE VARIABLE FILTER The circuit shown in Figure 34 can be used to accurately program the Q factor; the cutoff frequency, fC; and the gain of a 2-pole state variable filter. The AD8684 has been used in this design because of its high bandwidth, low power, and low noise. This circuit takes only three packages to build because of the quad configuration of the op amps and DACs. The DACs shown are used in voltage mode; therefore, many values are dependent on the accuracy of the DAC only and not on the absolute values of the DAC resistive ladders. As a result, this makes the circuit unusually accurate for a programmable filter. Adjusting DAC 1 changes the signal amplitude across R1; therefore, the DAC attenuation × R1 determines the amount of signal current that charges the integrating capacitor, C1. This cutoff frequency can be expressed as ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ = 256 2π 1 D1 R1C1 f C where D1 is the digital code for the DAC. DAC3 is used to set the gain. The gain equation is ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ = 256 D3 R5 R4 Gain DAC 2 is used to set the Q of the circuit. Adjusting this DAC controls the amount of feedback from the band-pass node to the input summing node. Note that the digital value of the DAC is in the numerator; therefore, zero code is not a valid operating point. ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ = D2 R3 R2 Q 256 1/4 AD8684 1/4 DAC8408 R5 2kΩ R4 2kΩ 1/4 AD8684 1/4 AD8684 1/4 DAC8408 R1 2kΩ C1 1000pF 1/4 AD8684 1/4 AD8684 1/4 DAC8408 R1 2kΩ C1 1000pF 1/4 AD8684 1/4 DAC8408 R2 2kΩ R3 2kΩ 1/4 AD8684 1/4 AD8684 R6 2kΩ HIGH PASS BAND PASS LOW PASS VIN R7 2kΩ DAC 3 DAC 1 DAC 4 DAC 2 Figure 34. Programmable State Variable Filter |
Số phần tương tự - AD8682 |
|
Mô tả tương tự - AD8682 |
|
|
Link URL |
Chính sách bảo mật |
ALLDATASHEET.VN |
Cho đến nay ALLDATASHEET có giúp ích cho doanh nghiệp của bạn hay không? [ DONATE ] |
Alldatasheet là | Quảng cáo | Liên lạc với chúng tôi | Chính sách bảo mật | Trao đổi link | Tìm kiếm theo nhà sản xuất 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 |