廬
APPLICATION BULLETIN
Mailing Address: PO Box 11400 鈥?Tucson, AZ 85734 鈥?Street Address: 6730 S. Tucson Blvd. 鈥?Tucson, AZ 85706
Tel: (602) 746-1111 鈥?Twx: 910-952-111 鈥?Telex: 066-6491 鈥?FAX (602) 889-1510 鈥?Immediate Product Info: (800) 548-6132
DIGITALLY PROGRAMMABLE, TIME-CONTINUOUS
ACTIVE FILTER
by Johnnie Molina, (602) 746-7592
Programmable active filters have increased in popularity
over the past decade. With the advent of switched capacitor
topologies, filter parameters such as the natural frequency
and filter Q can be changed simply by varying the clock
frequency. But switched capacitor filters are sampled data
systems and are subject to anomalies such as clock
feedthrough noise and aliasing errors.
The circuit in Figure 1 shows how an analog, digitally
programmable filter can be built using a UAF42. This
monolithic, state-variable active filter chip provides a two
pole filter building block with low sensitivity to external
component variations. It eliminates aliasing errors and clock
feedthrough noise common to switched capacitor filters.
Lowpass, highpass, bandpass and notch (band reject) out-
puts are available simultaneously.
Digital
Word
In
Pins
4
17
15
18
D
1
- D
12
Pins
4
OPA627
17
15
18
OPA627
DAC7541A
2
1
DAC7541A
2
1
R
F1
13k鈩?/div>
R
F2
13k鈩?/div>
10k鈩?/div>
R
Q
35.4k鈩?/div>
13
8
50k鈩?/div>
7
14
1
UAF42
10k鈩?/div>
5
10k鈩?/div>
R
G
49.9k鈩?/div>
In
12
50k鈩?/div>
C
1
1000pF
C
2
1000pF
Aux Amp
Out
6
50k鈩?/div>
(NC)
2
50k鈩?/div>
3
(13)
9
V鈥?/div>
10
V+
(7)
11
(1)
4
High-Pass
Out
Band-Pass
Out
Low-Pass
Out
Notch
Out
FIGURE 1. Digitally Programmable Analog Filter.
漏
1994 Burr-Brown Corporation
AB-062
Printed in U.S.A. February, 1994
AB-062相關(guān)型號PDF文件下載
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型號
版本
描述
廠商
下載
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英文版
AB-001 - INCREASING INA117 DIFFERENTIAL INPUT RANGE
ETC
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英文版
AB-002 - MAKE A PRECISION CURRENT SOURCE OR CURRENT SINK
ETC
-
英文版
AB-003 - VOLTAGE-REFERENCE FILTERS
ETC
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英文版
AB-004 - MAKE A PRECISION -10V REFERENCE
ETC
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英文版
AB-005 - Make A Precision -10V Reference
ETC
-
英文版
AB-006 - Make a -10V to +10V Adjustable Precision Voltage So...
ETC
-
英文版
AB-007 - CLASSICAL OP AMP OR CURRENT-FEEDBACK OP AMP?
ETC
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英文版
AB-008 - AC COUPLING INSTRUMENTATION AND DIFFERENCE AMPLIFIE...
ETC
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英文版
AB-009 - SINGLE-SUPPLY OPERATION OF ISOLATION AMPLIFIERS
ETC
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英文版
AB-010 - -200V DIFFERENCE AMPLIFIER WITH COMMON-MODE VOLTAGE...
ETC
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英文版
AB-011 - LOW POWER SUPPLY VOLTAGE OPERATION OF REF102 10.0V ...
ETC
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英文版
AB-012 - BOOST ISO120 BANDWIDTH TO MORE THAN 100kHz
ETC
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英文版
AB-013 - INCREASING ADC603 INPUT RANGE
ETC
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英文版
AB-014 - INPUT OVERLOAD PROTECTION FOR THE RCV420 4-20mA CUR...
ETC
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英文版
AB-015 - EXTENDING THE COMMON-MODE RANGE OF DIFFERENCE AMPLI...
ETC
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英文版
AB-016 - BOOST AMPLIFIER OUTPUT SWING WITH SIMPLE MODIFICATI...
ETC
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英文版
AB-017 - Sallen-Key Low-Pass Filter Design Program
ETC
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英文版
AB-018 - 0 TO 20mA RECEIVER USING RCV420
ETC
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英文版
AB-019 - USING THE ADS7800 12 BIT ADC WITH UNIPOLAR INPUT SI...
ETC
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英文版
AB-020 - BURR-BROWN SPICE BASED MACROMODELS. REV. F
ETC
1
2
3
