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
BUILD A THREE PHASE SINE WAVE GENERATOR
WITH THE UAF42
By Johnnie Molina (602) 746-7592
Figure 1 shows how a three phase sine wave oscillator can
be built using one UAF42 state variable filter along with
some resistors and diodes. Three output nodes are available;
highpass out, bandpass out and lowpass out. The signal at
the bandpass and lowpass out nodes are 90擄 and 180擄 out of
phase, respectively, with the highpass out node. An on-chip
auxiliary op amp is available for use as a buffer or gain
stage.
SETTING THE FREQUENCY OF OSCILLATION
The frequency of oscillation is set with resistors R
F1
and R
F2
using Equation 1.
f
OSC
=
Where,
1
2
蟺
RC
(1)
R = R
F1
= R
F2
C = C
1
= C
2
= 1000pF
The max f
OSC
obtainable using the UAF42 state variable
filter is 100kHz. Distortion becomes a factor though for
frequencies above 10kHz. For low frequencies of oscillation
(f
OSC
< 100Hz), the use of external capacitors is recom-
mended. They should be placed in parallel with the inter-
nally supplied C
1
and C
2
capacitors. This will reduce the
V+
R
1
A sin(蠅t)
Highpass
Out
R
F1
R
FB
12
13
8
50k鈩?/div>
UAF42
C
1
1000pF
C
2
1000pF
Auxiliary
Amp
7
C
EXT(1)
1N914
A sin(蠅t + 90擄)
Bandpass
Out
R
F2
A sin(蠅t + 180擄)
Lowpass Out
C
EXT(1)
5
14
1
R
2
50k鈩?/div>
6
50k鈩?/div>
2
3
50k鈩?/div>
8
1N914
7
R
4
9
V鈥?/div>
10
V+
11
4
R
3
NOTE: (1) C
EXT
is required for f
OSC
鈮?/div>
100Hz鈥攕ee text.
V鈥?/div>
FIGURE 1. Three Phase Quadrature Oscillator.
漏
1994 Burr-Brown Corporation
AB-096
1
Printed in U.S.A. July, 1994
AB-096相關(guān)型號(hào)PDF文件下載
-
型號(hào)
版本
描述
廠商
下載
-
英文版
AB-001 - INCREASING INA117 DIFFERENTIAL INPUT RANGE
ETC
-
英文版
AB-002 - MAKE A PRECISION CURRENT SOURCE OR CURRENT SINK
ETC
-
英文版
AB-003 - VOLTAGE-REFERENCE FILTERS
ETC
-
英文版
AB-004 - MAKE A PRECISION -10V REFERENCE
ETC
-
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
-
英文版
AB-008 - AC COUPLING INSTRUMENTATION AND DIFFERENCE AMPLIFIE...
ETC
-
英文版
AB-009 - SINGLE-SUPPLY OPERATION OF ISOLATION AMPLIFIERS
ETC
-
英文版
AB-010 - -200V DIFFERENCE AMPLIFIER WITH COMMON-MODE VOLTAGE...
ETC
-
英文版
AB-011 - LOW POWER SUPPLY VOLTAGE OPERATION OF REF102 10.0V ...
ETC
-
英文版
AB-012 - BOOST ISO120 BANDWIDTH TO MORE THAN 100kHz
ETC
-
英文版
AB-013 - INCREASING ADC603 INPUT RANGE
ETC
-
英文版
AB-014 - INPUT OVERLOAD PROTECTION FOR THE RCV420 4-20mA CUR...
ETC
-
英文版
AB-015 - EXTENDING THE COMMON-MODE RANGE OF DIFFERENCE AMPLI...
ETC
-
英文版
AB-016 - BOOST AMPLIFIER OUTPUT SWING WITH SIMPLE MODIFICATI...
ETC
-
英文版
AB-017 - Sallen-Key Low-Pass Filter Design Program
ETC
-
英文版
AB-018 - 0 TO 20mA RECEIVER USING RCV420
ETC
-
英文版
AB-019 - USING THE ADS7800 12 BIT ADC WITH UNIPOLAR INPUT SI...
ETC
-
英文版
AB-020 - BURR-BROWN SPICE BASED MACROMODELS. REV. F
ETC
1
2
