
XR-8038A
6
Rev. 2.01
SYSTEM DESCRIPTION
The XR-8038A precision waveform generator produces
highly stable and sweepable square, triangle, and sine
waves across eight frequency decades. The device time
base employs resistors and a capacitor for frequency and
duty cycle determination. The generator contains dual
comparators, a flip-flop driving a switch, current sources,
buffers, and a sine wave convertor. Three identical
frequency outputs are simultaneously available. Supply
voltage can range from 10V to 30V, or
±
5V to
±
15V with
dual supplies.
Unadjusted sine wave distortion is typically less than
0.7% with the sine wave distortion adjust pin (Pin 1) open.
Distortion levels may be improved by including a 100k
potentiometer between the supplies, with the wiper
connected to Pin 1.
Small frequency deviation (FM) is accomplished by
applying modulation voltage to Pins 7 and 8; large
frequency deviation (sweeping) is accomplished by
applying voltage to Pin 8 only. Sweep range is typically
1000:1.
The square wave output is an open collector transistor;
output amplitude swing closely approaches the supply
voltage. Triangle output amplitude is typically 1/3 of the
supply, and sine wave output reaches 0.22 of the supply
voltage.
Converter
TC
SA1
SA2
SWO
TWO
SQO
DCA2
DCA1
FMBI
FMSI
U1
Timing
Circuitry
Converter
S1
C1
+15V
–15V
Sine Wave
Triangle Wave
Square Wave
10
1
12
2
3
9
5
4
6
7
8
11
XR-8038A
Square Wave
Sine
V
CC
Figure 2. Generalized Test Circuit
R
A
R
B
V
EE
R
L