_______________General Description
The MAX038 is a high-frequency, precision function
generator producing accurate, high-frequency triangle,
sawtooth, sine, square, and pulse waveforms with a
minimum of external components. The output frequency
can be controlled over a frequency range of 0.1Hz to
20MHz by an internal 2.5V bandgap voltage
reference and an external resistor and capacitor. The
duty cycle can be varied over a wide range by applying
a ±2.3V control signal, facilitating pulse-width modula-
tion and the generation of sawtooth waveforms.
Frequency modulation and frequency sweeping are
achieved in the same way. The duty cycle and
frequency controls are independent.
Sine, square, or triangle waveforms can be selected at
the output by setting the appropriate code at two
TTL-compatible select pins. The output signal for all
waveforms is a 2V
P-P
signal that is symmetrical around
ground. The low-impedance output can drive up
to ±20mA.
The TTL-compatible SYNC output from the internal
oscillator maintains a 50% duty cycle--regardless of
the duty cycle of the other waveforms--to synchronize
other devices in the system. The internal oscillator can
be synchronized to an external TTL clock connected
to PDI.
________________________Applications
Precision Function Generators
Voltage-Controlled Oscillators
Frequency Modulators
Pulse-Width Modulators
Phase-Locked Loops
Frequency Synthesizer
FSK Generator--Sine and Square Waves
____________________________Features
o
0.1Hz to 20MHz Operating Frequency Range
o
Triangle, Sawtooth, Sine, Square, and Pulse
Waveforms
o
Independent Frequency and Duty-Cycle
Adjustments
o
350 to 1 Frequency Sweep Range
o
15% to 85% Variable Duty Cycle
o
Low-Impedance Output Buffer: 0.1
o
Low-Distortion Sine Wave: 0.75%
o
Low 200ppm/°C Temperature Drift
______________Ordering Information
*
Contact factory for dice specifications.
MAX038
High-Frequency Waveform Generator
________________________________________________________________
Maxim Integrated Products
1
20
19
18
17
16
15
14
13
12
11
1
2
3
4
5
6
7
8
9
10
V-
OUT
GND
V+
A1
A0
GND
REF
TOP VIEW
MAX038
DV+
DGND
SYNC
PDI
FADJ
DADJ
GND
COSC
PDO
GND
IIN
GND
DIP/SO
__________________Pin Configuration
19-0266; Rev 2a; 9/96
PART
TEMP. RANGE
PIN-PACKAGE
MAX038CPP
0°C to +70°C
20 Plastic DIP
MAX038CWP
0°C to +70°C
20 SO
MAX038C/D
0°C to +70°C
Dice*
MAX038EPP
-40°C to +85°C
20 Plastic DIP
MAX038EWP
-40°C to +85°C
20 SO
EVALUATION KIT
AVAILABLE
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
MAX038
High-Frequency Waveform Generator
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, GND = DGND = 0V, V+ = DV+ = 5V, V- = -5V, V
DADJ
= V
FADJ
= V
PDI
= V
PDO
= 0V, C
F
= 100pF,
R
IN
= 25k
, R
L
= 1k
, C
L
= 20pF, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
Frequency Temperature
Coefficient
F
o
/°C
200
ppm/°C
600
IIN Offset Voltage
V
IN
±1.0
±2.0
mV
Frequency Programming
Current
I
IN
1.25
375
µA
(
F
o
/F
o
)
V+
±0.4
±2.00
Frequency Power-Supply
Rejection
(
F
o
/F
o
)
V-
±0.2
±1.00
%/V
Output Peak-to-Peak Symmetry
V
OUT
±4
mV
Maximum Operating Frequency
F
o
20.0
40.0
MHz
2.50
750
Output Resistance
R
OUT
0.1
0.2
Output Short-Circuit Current
I
OUT
40
mA
Amplitude
V
OUT
1.9
2.0
2.1
V
P-P
Rise Time
t
R
12
ns
Fall Time
t
F
12
ns
Duty Cycle
dc
47
50
53
%
Amplitude
V
OUT
1.9
2.0
2.1
V
P-P
Nonlinearity
0.5
%
Duty Cycle
dc
47
50
53
%
CONDITIONS
V
FADJ
= -3V
V
FADJ
= 0V
V
FADJ
= -3V
V- = -5V, V+ = 4.75V to 5.25V
V+ = 5V, V- = -4.75V to -5.25V
Short circuit to GND
10% to 90%
90% to 10%
V
DADJ
= 0V, dc = t
ON
/t x 100%
15pCF
15pF, I
IN
= 500µA
V
FADJ
= 0V
F
o
= 100kHz, 5% to 95%
V
DADJ
= 0V (Note 1)
V+ to GND ................................................................-0.3V to +6V
DV+ to DGND...........................................................-0.3V to +6V
V- to GND .................................................................+0.3V to -6V
Pin Voltages
IIN, FADJ, DADJ, PDO .....................(V- - 0.3V) to (V+ + 0.3V)
COSC .....................................................................+0.3V to V-
A0, A1, PDI, SYNC, REF.........................................-0.3V to V+
GND to DGND ................................................................±0.3V
Maximum Current into Any Pin .........................................±50mA
OUT, REF Short-Circuit Duration to GND, V+, V- ...............30sec
Continuous Power Dissipation (T
A
= +70°C)
Plastic DIP (derate 11.11mW/°C above +70°C) ..........889mW
SO (derate 10.00mW/°C above +70°C) .......................800mW
CERDIP (derate 11.11mW/°C above +70°C) ...............889mW
Operating Temperature Ranges
MAX038C_ _ .......................................................0°C to +70°C
MAX038E_ _ ....................................................-40°C to +85°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
Amplitude
V
OUT
1.9
2.0
2.1
V
P-P
Duty cycle adjusted to 50%
0.75
Total Harmonic Distortion
THD
Duty cycle unadjusted
1.50
%
F
o
/°C
FREQUENCY CHARACTERISTICS
OUTPUT AMPLIFIER (applies to all waveforms)
SQUARE-WAVE OUTPUT (R
L
= 100
)
TRIANGLE-WAVE OUTPUT (R
L
= 100
)
SINE-WAVE OUTPUT (R
L
= 100
)
MAX038
High-Frequency Waveform Generator
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, GND = DGND = 0V, V+ = DV+ = 5V, V- = -5V, V
DADJ
= V
FADJ
= V
PDI
= V
PDO
= 0V, C
F
= 100pF,
R
IN
= 25k
, R
L
= 1k
, C
L
= 20pF, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
Note 1:
Guaranteed by duty-cycle test on square wave.
Note 2:
V
REF
is independent of V-.
PARAMETER
DADJ Nonlinearity
SYMBOL
MIN
TYP
MAX
dc/V
FADJ
2
4
UNITS
%
Duty Cycle
dc
SYNC
50
%
Fall Time
t
F
10
ns
Rise Time
t
R
10
ns
Change in Output Frequency
with DADJ
DADJ Input Current
I
DADJ
190
250
320
µA
DADJ Voltage Range
V
DADJ
±2.3
V
F
o
/V
DADJ
±2.5
±8
%
Duty-Cycle Adjustment Range
dc
15
85
%
Maximum DADJ Modulating
Frequency
F
DC
2
MHz
Output Low Voltage
FADJ Input Current
I
FADJ
190
250
320
µA
FADJ Voltage Range
V
FADJ
±2.4
V
Frequency Sweep Range
V
OL
0.3
0.4
V
F
o
±70
%
FM Nonlinearity with FADJ
Output High Voltage
F
o
/V
FADJ
±0.2
%
V
OH
2.8
3.5
V
Change in Duty Cycle with FADJ
dc/V
FADJ
±2
%
Output Voltage
V
REF
2.48
2.50
2.52
V
CONDITIONS
-2V
V
DADJ
2V
90% to 10%, R
L
= 3k
, C
L
= 15pF
10% to 90%, R
L
= 3k
, C
L
= 15pF
-2V
V
DADJ
2V
-2.3V
V
DADJ
2.3V
I
SINK
= 3.2mA
-2.4V
V
FADJ
2.4V
-2V
V
FADJ
2V
I
SOURCE
= 400µA
-2V
V
FADJ
2V
I
REF
= 0
Temperature Coefficient
V
REF
/°C
20
ppm/°C
0mA
I
REF
4mA (source)
1
2
Load Regulation
V
REF
/I
REF
-100µA
I
REF
0µA (sink)
1
4
mV/mA
Line Regulation
V
REF
/V+
4.75V
V+
5.25V (Note 2)
1
2
mV/V
Input Low Voltage
V
IL
0.8
V
Input High Voltage
V
IH
2.4
V
Input Current (A0, A1)
I
IL
, I
IH
V
A0
, V
A1
= V
IL
, V
IH
±5
µA
Input Current (PDI)
I
IL
, I
IH
V
PDI
= V
IL
, V
IH
±25
µA
Positive Supply Voltage
V+
4.75
5.25
V
SYNC Supply Voltage
DV+
4.75
5.25
V
Negative Supply Voltage
V-
-4.75
-5.25
V
Positive Supply Current
I+
35
45
mA
SYNC Supply Current
I
DV+
1
2
mA
Negative Supply Current
I-
45
55
mA
Maximum FADJ Modulating
Frequency
F
F
2
MHz
SYNC OUTPUT
DUTY-CYCLE ADJUSTMENT (DADJ)
FREQUENCY ADJUSTMENT (FADJ)
VOLTAGE REFERENCE
LOGIC INPUTS (A0, A1, PDI)
POWER SUPPLY
MAX038
High-Frequency Waveform Generator
4
_______________________________________________________________________________________
__________________________________________Typical Operating Characteristics
(Circuit of Figure 1, V+ = DV+ = 5V, V- = -5V, V
DADJ
= V
FADJ
= V
PDI
= V
PDO
= 0V, R
L
= 1k
, C
L
= 20pF, T
A
= +25°C, unless
otherwise noted.)
0.1
1
100
1000
OUTPUT FREQUENCY
vs. IIN CURRENT
10
100
MAX038-08
IIN CURRENT (
µ
A)
OUTPUT FREQUENCY (Hz)
10
1
1k
10k
100k
1M
10M
100M
100
µ
F
47
µ
F
10
µ
F
3.3
µ
F
1
µ
F
100nF
33nF
3.3nF
330pF
100pF
33pF
1.0
0
-3
2
NORMALIZED OUTPUT FREQUENCY
vs. FADJ VOLTAGE
0.2
0.8
MAX038-09
V
FADJ
(V)
F
OUT
NORMALIZED
0
0.4
-2
-1
1
0.6
3
1.2
1.4
1.6
1.8
2.0
I
IN
= 100
µ
A, COSC = 1000pF
0.85
NORMALIZED OUTPUT FREQUENCY
vs. DADJ VOLTAGE
0.90
1.10
MAX038-17
DADJ (V)
NORMALIZED OUTPUT FREQUENCY
1.00
0.95
1.05
I
IN
= 10
µ
A
I
IN
= 25
µ
A
I
IN
= 50
µ
A
I
IN
= 100
µ
A
I
IN
= 250
µ
A
I
IN
= 500
µ
A
2.0
-2.5
-2.0
-1.0
1.0
2.5
DUTY-CYCLE LINEARITY
vs. DADJ VOLTAGE
-2.0
1.0
MAX038-18
DADJ
(V)
DUTY-CYCLE LINEARITY ERROR (%)
0
1.5
0
-1.0
-1.5
-0.5
0.5
1.5
I
IN
= 10
µ
A
I
IN
= 25
µ
A
I
IN
= 50
µ
A
I
IN
= 100
µ
A
I
IN
= 250
µ
A
I
IN
= 500
µ
A
60
0
-3
2
DUTY CYCLE vs. DADJ VOLTAGE
10
50
MAX038-16B
DADJ (V)
DUTY CYCLE (%)
0
30
20
-2
-1
1
40
70
80
90
100
3
I
IN
= 200
µ
A
MAX038
High-Frequency Waveform Generator
_______________________________________________________________________________________
5
SINE-WAVE OUTPUT (50Hz)
TOP: OUTPUT 50Hz = F
o
BOTTOM: SYNC
I
IN
= 50
µ
A
C
F
= 1
µ
F
TRIANGLE-WAVE OUTPUT (50Hz)
TOP: OUTPUT 50Hz = F
o
BOTTOM: SYNC
I
IN
= 50
µ
A
C
F
= 1
µ
F
SQUARE-WAVE OUTPUT (50Hz)
TOP: OUTPUT 50Hz = F
o
BOTTOM: SYNC
I
IN
= 50
µ
A
C
F
= 1
µ
F
SINE-WAVE OUTPUT (20MHz)
I
IN
= 400
µ
A
C
F
= 20pF
____________________________Typical Operating Characteristics (continued)
(Circuit of Figure 1, V+ = DV+ = 5V, V- = -5V, V
DADJ
= V
FADJ
= V
PDI
= V
PDO
= 0V, R
L
= 1k
, C
L
= 20pF, T
A
= +25°C, unless
otherwise noted.)
TRIANGLE-WAVE OUTPUT (20MHz)
I
IN
= 400
µ
A
C
F
= 20pF
PDF 
ZIP