VERY HIGH ACCURACY: 7.071 Vrms 0.05%
EXTREMELY LOW DRIFT:
3 ppm/C (-55C to +125C)
EXCELLENT STABILITY: 10 ppm/1000 Hrs. Typ.
LOW DISTORTION:
0.1% THD @ f = 3300 Hz
HERMETIC 14-PIN CERAMIC DIP
MILITARY PROCESSING OPTION
SWR200
Precision
Sine Wave Reference
DESCRIPTION
APPLICATIONS
TRANSDUCER EXCITATION
HIGH RESOLUTION SERVO SYSTEMS
HIGH PRECISION TEST and
MEASUREMENT INSTRUMENTS
AC VOLTAGE STANDARD
LVDT OR RVDT REFERENCE
MULTIPLYING D/A REFERENCE
FEATURES
SELECTION GUIDE
Type
Output
(Typ.)
Temperature
Operating Range
Package
SWR200C
7.071V -25C to +85C
DIP
SWR200M
7.071V -55C to +125C
DIP
SWR200 is a Precision Sine Wave Reference
providing an ultra stable sine wave output of
7.071V at 0.05% initial accuracy and
temperature coefficient as low as 3 ppm/C over
the full military temperature range. The extreme
accuracy is made possible by a chopper-based
AGC circuit. The temperature characteristic of the
chopper circuit compensates the typical
nonlinearity of the internal DC zener reference,
resulting in a nearly linear amplitude-temperature
characteristic. Frequency of the SWR200 is
programmable with two external capacitors.
The SWR200 is available in a 14-pin bottom
braze package. They are hermetically sealed and
"M" versions are screened for high reliability and
quality.
SWR200 is well suited for any application
requiring a stable sine wave source. The SWR200
can be used as a reference source in precision
sensing systems based on LVDT or RVDT
position sensors. A programmable AC reference
can be constructed using the SWR200 as a
reference for a high accuracy multiplying Digital to
Analog Converter.
SWR200DS REV. D JUNE 1995
THALER CORPORATION 2015 N. FORBES BOULEVARD TUCSON, AZ. 85745 (520) 882-4000
MODEL
C
M
PARAMETERS
MIN TYP MAX MIN TYP MAX MIN TYP MAX MIN TYP MAX
UNITS
ABSOLUTE MAXIMUM RATINGS
Power Supply
13.5 15
22
*
*
V
Operating Temperature -25
85
-55
125
C
Storage Temperature
-65
150
*
*
C
Short Circuit Protection
Continuous
*
OUTPUT VOLTAGE
7.071
*
Vrms
OUTPUT VOLTAGE ERRORS
Initial Error
0.05
*
%
Warmup Drift
100
*
V
DC Offset
3
*
mV
DC Offset Over Temp.
3
18
*
*
V/C
Tmin - Tmax
1
2.0
1
3.0
ppm/C
Long-Term Stability
10
*
ppm/C
OUTPUT CURRENT
Range
10
*
mA
REGULATION
Line
10
*
ppm/V
Load
3
*
ppm/mA
POWER SUPPLY CURRENTS
+PS
10.5
13
*
*
mA
-PS
9.5
13
*
*
mA
DISTORTION
0.5
*
%
FREQUENCY
.98
1
1.02
*
*
*
Hz
400
10K
*
Hz
15
*
ppm/C
SWR200
NOTES:
*Same as C Models.
1.Using the box method, the specified value is the
maximum deviation from the output voltage at 25C
over the specified operating temperature range.
2.The specified values are unloaded.
3.Pin 8 is internally connected to Pin 7 and can be
used as Ref. GND.
4. The frequency range can be extended to any desired
lower value by using 2 external AGC capacitors (see
AN-3).
5.The increase in distrotion at lower frequencies can be
eliminated by using external AGC capacitors (see
AN-3).
f =
10 -5
C1 C2
Range (f)
vs. Temperature
f
f
SWR200DS REV. D JUNE 1995
Vps =15V, T = 25C, RL = 10K
unless otherwise noted.
ELECTRICAL SPECIFICATIONS
TYPICAL PERFORMANCE CURVES
SWR200DS REV. D JUNE 1995
Temperature
o
C
SWR200C
V
OUT
vs. TEMPERATURE
V
OUT
vs. TEMPERATURE
%
FREQ. vs. TEMP.
Temperature
o
C
SWR200L
Temperature
o
C
SWR200C
Temperature
o
C
SWR200L
DISTORTION VS. TEMP
Temperature
o
C
DISTORTION vs. FREQUENCY
Frequency (Hz)
NORMALIZED DISTORTION vs. C2/C1
C2/C1
POWER SUPPLY CURRENT vs. TEMP.
Temperature
o
C
CASE TEMP. RISE ABOVE AMBIENT
vs. OUTPUT CURRENT
Output Current (mA)
JUNCTION TEMP. RISE
ABOVE CASE TEMP. vs
OUTPUT CURRENT
Output Current (mA)
%
FREQ. vs. TEMP.
DISCUSSION OF PERFORMANCE
THEORY OF OPERATION
The following refers to the schematic in Figure 1.
A1 and A2 are connected as a phase-shift oscillator
circuit with the frequency set by the external
capacitors C1 and C2. Q4 is included in the
feedback loop of A1 as a gain control element.
The oscillator output is fed to the chopper amplifier
which develops an absolute value representation of
the oscillator output. The chopper output is
compared to a precision DC reference in integrator
amplifier A3. This DC error signal is used ot control
the gain setting FET Q4.
As in all precision zener based DC references, the
drift of the zener becomes nonlinear at temperature
extremes. The chopper amplifier drift characteristic
is complementary to this nonlinearity and
compensates for the reference drift.
APPLICATION INFORMATION
Figure 1 shows the connections for the SWR200
including the two frequency setting capacitors. The
frequency is:
The frequency stability is directly related to the
stability of the capacitors, therefore stable capacitors
like NPO ceramic, or polycarbonate or polystyrene
film should be used.
Two separate ground pins are provided for
accurate ground sensing. This minimizes errors due
to drops in the ground pin which can become a
significant source of error in sockets.
The offset of the SWR200 is fully specified for
initial offset and drift and is low enough that it can
normally be neglected. In applications which are
especially sensitive to offset the output can be AC
coupled. Proper capacitor sizing and high impedance
sensing will minimize errors due to capacitive
coupling.
f =
10
C C
-5
SCHEMATIC
FIGURE 1
1
2
SWR200DS REV. D JUNE 1995
INCHES MILLIMETER
14-PIN HYBRID
PACKAGE
TOP VIEW
SWR200
NC
NC
OUTPUT
GND SENSE
GND
NC
NC
NC
C1
C1
-PS
C2
+PS
C2
DIM
MIN
MAX
MIN
MAX
DIM
MIN
MAX
MIN
MAX
E
.480
.500
12.1
12.7
A
.120
.155
3.0
4.0
L
.195
.215
4.9
5.4
Q
.015
.035
0.4
0.9
D
.775
.805
19.7
20.4
Q1
N/A
.030
N/A
0.7
B
.016
.020
0.4
0.5
C
.009
.012
0.2
0.3
B1
.038
.042
0.9
1.0
G1
.290
.310
7.3
7.8
B2
.095
.105
2.4
2.6
S
.085
.105
2.1
2.6
P
.004
.006
0.10
0.15
EXTERNAL CONNECTIONS
FIGURE 2
INCHES MILLIMETER
MECHANICAL
PIN CONFIGURATION
SWR200DS REV. D JUNE 1995
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