- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383497 > MAX7410 (Maxim Integrated Products, Inc.) 5th-order，lowpass，switched-capacitor filters PDF資料下載
參數(shù)資料
| 型號： | MAX7410 |
| 廠商： | Maxim Integrated Products, Inc. |
| 英文描述： | 5th-order，lowpass，switched-capacitor filters |
| 中文描述： | 五階、低通、開關(guān)電容濾波器 |
| 文件頁數(shù)： | 8/12頁 |
| 文件大小： | 134K |
| 代理商： | MAX7410 |
M
5th-Order, Lowpass,
S witc hed-Capac itor Filters
8
_______________________________________________________________________________________
The difference between Bessel and Butterworth filters
can be observed when a 1kHz square wave is applied
to the filter input (Figure 1, trace A). With the filter cutoff
frequencies set at 5kHz, trace B shows the Bessel filter
response and trace C shows the Butterworth filter
response.
Bac kground Information
Most switched-capacitor filters (SCFs) are designed with
biquadratic sections. Each section implements two filter-
ing poles, and the sections are cascaded to produce
higher-order filters. The advantage to this approach is
ease of design. However, this type of design is highly
sensitive to component variations if any section’s Q is
high. An alternative approach is to emulate a passive net-
work using switched-capacitor integrators with summing
and scaling. Figure 2 shows a basic 5th-order ladder filter
structure.
A switched-capacitor filter such as the MAX7409/
MAX7410/MAX7413/MAX7414 emulates a passive ladder
filter. The filter’s component sensitivity is low when com-
pared to a cascaded biquad design, because each
component affects the entire filter shape, not just one
pole-zero pair. In other words, a mismatched component
in a biquad design will have a concentrated error on its
respective poles, while the same mismatch in a ladder
filter design results in an error distributed over all poles.
Cloc k S ignal
External Clock
The MAX7409/MAX7410/MAX7413/MAX7414 family of
SCFs is designed for use with external clocks that have
a 50% ±10% duty cycle. When using an external clock
with these devices, drive CLK with a CMOS gate pow-
ered from 0 to V
DD
. Varying the rate of the external
clock adjusts the corner frequency of the filter as fol-
lows:
f
C
= f
CLK
/ 100
Internal Clock
When using the internal oscillator, connect a capacitor
(C
OSC
) between CLK and ground. The value of the
capacitor determines the oscillator frequency as follows:
f
OSC
(kHz) = 30 x 10
3
/ C
OSC
(pF)
Minimize the stray capacitance at CLK so that it does
not affect the internal oscillator frequency. Vary the rate
of the internal oscillator to adjust the filter’s corner fre-
quency by a 100:1 clock-to-corner frequency ratio. For
example, an internal oscillator frequency of 100kHz
produces a nominal corner frequency of 1kHz.
Input Impedanc e vs. Cloc k Frequenc ies
The MAX7409/MAX7410/MAX7413/MAX7414’s input
impedance is effectively that of a switched-capacitor
resistor (see the following equation), and is inversely
proportional to frequency. The input impedance values
determined below represent the average input imped-
ance, since the input current is not continuous. As a
rule, use a driver with an output impedance less than
10% of the filter’s input impedance. Estimate the input
impedance of the filter using the following formula:
Z
IN
= 1 / ( f
CLK
x 2.1pF)
For example, an f
CLK
of 100kHz results in an input
impedance of 4.8M
.
L4
C5
C3
C1
V
IN
+
-
R
L
L2
R
S
Figure 2. 5th-Order Ladder Filter Network
A
2V/div
2V/div
2V/div
C
A: 1kHz INPUT SIGNAL
B: MAX7409 BESSEL FILTER RESPONSE; f
C
= 5kHz
C: MAX7410 BUTTERWORTH FILTER RESPONSE; f
C
= 5kHz
B
200
μ
s/div
Figure 1. Bessel vs. Butterworth Filter Response
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX7410CPA | 5th-Order, Lowpass, Switched-Capacitor Filters |
| MAX7413 | 5th-Order, Lowpass, Switched-Capacitor Filters |
| MAX7413CPA | 5th-Order, Lowpass, Switched-Capacitor Filters |
| MAX7413EPA | 5th-Order, Lowpass, Switched-Capacitor Filters |
| MAX7413EUA | 5th-Order, Lowpass, Switched-Capacitor Filters |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX7410CPA | 功能描述:有源濾波器 RoHS:否 制造商:Maxim Integrated 通道數(shù)量:1 截止頻率:150 KHz 電源電壓-最大:11 V 電源電壓-最小:4.74 V 最大工作溫度:+ 85 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP N 封裝:Tube |
| MAX7410CPA+ | 功能描述:有源濾波器 5th-Order Lowpass Elliptic Filter RoHS:否 制造商:Maxim Integrated 通道數(shù)量:1 截止頻率:150 KHz 電源電壓-最大:11 V 電源電壓-最小:4.74 V 最大工作溫度:+ 85 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP N 封裝:Tube |
| MAX7410CUA | 功能描述:有源濾波器 RoHS:否 制造商:Maxim Integrated 通道數(shù)量:1 截止頻率:150 KHz 電源電壓-最大:11 V 電源電壓-最小:4.74 V 最大工作溫度:+ 85 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP N 封裝:Tube |
| MAX7410CUA+ | 功能描述:有源濾波器 5th-Order Lowpass Elliptic Filter RoHS:否 制造商:Maxim Integrated 通道數(shù)量:1 截止頻率:150 KHz 電源電壓-最大:11 V 電源電壓-最小:4.74 V 最大工作溫度:+ 85 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP N 封裝:Tube |
| MAX7410CUA+T | 功能描述:有源濾波器 5th-Order Lowpass Elliptic Filter RoHS:否 制造商:Maxim Integrated 通道數(shù)量:1 截止頻率:150 KHz 電源電壓-最大:11 V 電源電壓-最小:4.74 V 最大工作溫度:+ 85 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP N 封裝:Tube |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。