Monolithic
Function Generator
...the analog plus company
TM
June 1997-3
FEATURES
APPLICATIONS
Low-Sine Wave Distortion, 0.5%, Typical
Waveform Generation
Excellent Temperature Stability, 20ppm/
°
C, Typ.
Sweep Generation
Wide Sweep Range, 2000:1, Typical
AM/FM Generation
Low-Supply Sensitivity, 0.01%V, Typ.
V/F Conversion
Linear Amplitude Modulation
FSK Generation
TTL Compatible FSK Controls
Wide Supply Range, 10V to 26V
Phase-Locked Loops (VCO)
Adjustable Duty Cycle, 1% TO 99%
GENERAL DESCRIPTION
The XR-2206 is a monolithic function generator
integrated circuit capable of producing high quality sine,
square, triangle, ramp, and pulse waveforms of
high-stability and accuracy. The output waveforms can be
both amplitude and frequency modulated by an external
voltage. Frequency of operation can be selected
externally over a range of 0.01Hz to more than 1MHz.
C. The oscillator
frequency can be linearly swept over a 2000:1 frequency
range with an external control voltage, while maintaining
low distortion.
°
ORDERING INFORMATION
Part No.
Package
Operating
Temperature Range
XR-2206M
16 Lead 300 Mil CDIP
-55
°
C to +125
°
C
XR-2206P
16 Lead 300 Mil PDIP
–40
°
C to +85
°
C
XR-2206CP
16 Lead 300 Mil PDIP
0
°
C to +70
°
C
XR-2206D
16 Lead 300 Mil JEDEC SOIC
0
°
C to +70
°
C
Rev. 1.03
1972
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 (510) 668-7000 (510) 668-7017
1
The circuit is ideally suited for communications,
instrumentation, and function generator applications
requiring sinusoidal tone, AM, FM, or FSK generation. It
has a typical drift specification of 20ppm/
XR-2206
V
CC
GND
BIAS
4
12
10
11 SYNCO
TC1
5
Timing
Capacitor
VCO
TC2
6
Timing
Resistors
TR1
7
Current
Switches
Multiplier
And Sine
Shaper
TR2
8
+1
2
STO
FSKI
9
AMSI
1
3MO
WAVEA1
13
WAVEA2
14
SYMA1
15
SYMA2
16
Figure 1. XR-2206 Block Diagram
Rev. 1.03
2
XR-2206
AMSI
STO
MO
V
CC
TC1
TC2
TR1
TR2
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
SYMA2
SYMA1
WAVEA2
WAVEA1
GND
SYNCO
BIAS
FSKI
AMSI
STO
MO
V
CC
TC1
TC2
TR1
TR2
1
16
SYMA2
SYMA1
WAVEA2
WAVEA1
GND
SYNCO
BIAS
FSKI
2
3
4
5
6
7
15
14
13
12
11
10
8
9
16 Lead PDIP, CDIP (0.300”)
16 Lead SOIC (Jedec, 0.300”)
PIN DESCRIPTION
Pin #
Symbol
Type Description
1
AMSI
I
Amplitude Modulating Signal Input.
2
STO
O
Sine or Triangle Wave Output.
3
MO
O
Multiplier Output.
4
V
CC
Positive Power Supply.
5
TC1
I
Timing Capacitor Input.
6
TC2
I
Timing Capacitor Input.
7
TR1
O
Timing Resistor 1 Output.
8
TR2
O
Timing Resistor 2 Output.
9
FSKI
I
Frequency Shift Keying Input.
10
BIAS
O
Internal Voltage Reference.
11
SYNCO
O
Sync Output.
This output is a open collector and needs a pull up resistor to V
CC
.
12
GND
Ground pin.
13
WAVEA1
I
Wave Form Adjust Input 1.
14
WAVEA2
I
Wave Form Adjust Input 2.
15
SYMA1
I
Wave Symetry Adjust 1.
16
SYMA2
I
Wave Symetry Adjust 2.
Rev. 1.03
3
XR-2206
DC ELECTRICAL CHARACTERISTICS
Test Conditions: Test Circuit of Figure 2
Vcc
= 12V, T
A
= 25
°
C, C = 0.01
F, R
1
= 100k
, R
2
= 10k
, R
3
= 25k
Unless Otherwise Specified. S
1
open for triangle, closed for sine wave.
XR-2206M/P
XR-2206CP/D
Parameters
Min.
Typ.
Max.
Min.
Typ.
Max.
Units Conditions
General Characteristics
Single Supply Voltage
10
26
10
26
V
Split-Supply Voltage
+
5
+
13
+
5
+
13
V
Supply Current
12
17
14
20
mA
R
1
10k
Oscillator Section
Max. Operating Frequency
0.5
1
0.5
1
MHz C = 1000pF, R
1
= 1k
Lowest Practical Frequency
0.01
0.01
Hz
C = 50
F, R
1
= 2M
Frequency Accuracy
+
1
+
4
+
2
% of f
o
f
o
= 1/R
1
C
Temperature Stability
Frequency
+
10
+
50
+
20
ppm/
°
C 0
C
T
A
70
°
C
R
1
= R
2
= 20k
Sine Wave Amplitude Stability
2
4800
4800
ppm/
°
C
Supply Sensitivity
0.01
0.1
0.01
%/V
V
LOW
= 10V, V
HIGH
= 20V,
R
1
= R
2
= 20k
Sweep Range
1000:1 2000:1
2000:1
f
H
= f
L
f
H
@ R
1
= 1k
f
L
@ R
1
= 2M
Sweep Linearity
10:1 Sweep
2
2
%
f
L
= 1kHz, f
H
= 10kHz
1000:1 Sweep
8
8
%
f
L
= 100Hz, f
H
= 100kHz
FM Distortion
0.1
0.1
%
+
10% Deviation
Recommended Timing Components
Timing Capacitor: C
0.001
100
0.001
100
F
Figure 5
Timing Resistors: R
1
& R
2
1
2000
1
2000
k
Triangle Sine Wave Output
1
Figure 3
Triangle Amplitude
160
160
mV/k
Figure 2, S
1
Open
Sine Wave Amplitude
40
60
80
60
mV/k
Figure 2, S
1
Closed
Max. Output Swing
6
6
Vp-p
Output Impedance
600
600
Triangle Linearity
1
1
%
Amplitude Stability
0.5
0.5
dB
For 1000:1 Sweep
Sine Wave Distortion
Without Adjustment
2.5
2.5
%
R
1
= 30k
With Adjustment
0.4
1.0
0.5
1.5
%
See Figure 7 and Figure 8
Notes
1
Output amplitude is directly proportional to the resistance, R
3
, on Pin 3. See Figure 3.
2
For maximum amplitude stability, R
3
should be a positive temperature coefficient resistor.
Bold face parameters
are covered by production test and guaranteed over operating temperature range.
Rev. 1.03
4
°
XR-2206
DC ELECTRICAL CHARACTERISTICS
(CONT’D)
XR-2206M/P
XR-2206CP/D
Parameters
Min.
Typ.
Max.
Min.
Typ.
Max.
Units Conditions
Amplitude Modulation
Input Impedance
50
100
50
100
k
Modulation Range
100
100
%
Carrier Suppression
55
55
dB
Linearity
2
2
%
For 95% modulation
Square-Wave Output
Amplitude
12
12
Vp-p Measured at Pin 11.
Rise Time
250
250
ns
C
L
= 10pF
Fall Time
50
50
ns
C
L
= 10pF
Saturation Voltage
0.2
0.4
0.2
0.6
V
I
L
= 2mA
Leakage Current
0.1
20
0.1
100
A
V
CC
= 26V
FSK Keying Level (Pin 9)
0.8
1.4
2.4
0.8
1.4
2.4
V
See section on circuit controls
Reference Bypass Voltage
2.9
3.1
3.3
2.5
3
3.5
V
Measured at Pin 10.
Notes
1
Output amplitude is directly proportional to the resistance, R
3
, on Pin 3. See Figure 3.
2
For maximum amplitude stability, R
3
should be a positive temperature coefficient resistor.
Bold face parameters
are covered by production test and guaranteed over operating temperature range.
Specifications are subject to change without notice
ABSOLUTE MAXIMUM RATINGS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Dissipation
26V
Total Timing Current
. . . . . . . . . . . . . . . . . . . . . . . .
6mA
. . . . . . . . . . . . . . . . . . . . . . .
750mW
Storage Temperature
. . . . . . . . . . . .
-65
°
C to +150
°
C
Derate Above 25
°
C
. . . . . . . . . . . . . . . . . . . . . .
5mW/
°
C
SYSTEM DESCRIPTION
The XR-2206 is comprised of four functional blocks; a
voltage-controlled oscillator (VCO), an analog multiplier
and sine-shaper; a unity gain buffer amplifier; and a set of
current switches.
The VCO produces an output frequency proportional to
an input current, which is set by a resistor from the timing
terminals to ground. With two timing pins, two discrete
output frequencies can be independently produced for
FSK generation applications by using the FSK input
control pin. This input controls the current switches which
select one of the timing resistor currents, and routes it to
the VCO.
Rev. 1.03
5
Power Supply