1
DIGITAL
DIGITAL
DIGITAL
DIGITAL
DIRECT
DIRECT
DIRECT
DIRECT
COMPOSITE
COMPOSITE
COMPOSITE
COMPOSITE
FUNCTION
FUNCTION
FUNCTION
FUNCTION
GENERATOR
GENERATOR
GENERATOR
GENERATOR
OPERATION
OPERATION
OPERATION
OPERATION
MANUAL
MANUAL
MANUAL
MANUAL
1.
1.
1.
1.
GENERAL
GENERAL
GENERAL
GENERAL
The instrument is a DDS digital direct composite function generator. It is cored by CPU, employs many large scale integrated circuits, it has the following features:
(1)High precise for frequency, high stability.
(2)Purity waveform, small distortion.
(3)Non-transition process, fast frequency change-over time
：
can be stable instant
(4)Non-limitation on ranges
：
unnecessary to changes ranges, frequency covering factor can be 10
8.
(5)Sweeping characteristics
：
many kinds of sweeping modes are selectable and can pause randomly, LED will display the current frequency value; can sweep meticulously on
narrow band; can set initial frequency, terminal frequency, sweeping steps and time interval.
(6)Modulation characteristics
：
it has amplitude modulation function, the modulation signal can be generated by either inner signal source or outer input, the depth is adjusted
and will not be effected by carrier wave frequency and output amplitude.
(7)Convenient keyboard operation.
(8)Stability and reliability.
2.
2.
2.
2.
TECHNICAL
TECHNICAL
TECHNICAL
TECHNICAL
DATA
DATA
DATA
DATA
AND
AND
AND
AND
SPECIFICATON
SPECIFICATON
SPECIFICATON
SPECIFICATON
2-1.
2-1.
2-1.
2-1.
WAVEFORM
WAVEFORM
WAVEFORM
WAVEFORM
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
sine-wave, TTL level square wave
waveform amplitude resolution: 10bit
sine wave harmonic distortion: -40dBc
（
frequency
＜
1M Hz
）
,
-30dBc
（
frequency
≥
1M Hz
）
sine wave THD
： ＜
1% (high resistance, 1KHz)
TTL level square wave rise time:
≤
20ns
Square wave overshoot:
≤
5%
2-2.
2-2.
2-2.
2-2.
FREQUENCY
FREQUENCY
FREQUENCY
FREQUENCY
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
frequency range:
1Hz
——
3MHz
resolution:
less than 1MHz: 0.01Hz
；
1MHz and more than 1MHz: 0.1Hz
frequency tolerance:
≤ ±（
5
×
10
－
5
＋
30Hz+1d
）
frequency stability:
≤±
50ppm
（－
40
℃——＋
85
℃） （
use the low temperature drift crystal oscillator with PLL phase-lock circuit
）
. Custom-made can be done if frequency
stability requires to be
±
20ppm or less.
2-3.
2-3.
2-3.
2-3.
AMPLITUDE
AMPLITUDE
AMPLITUDE
AMPLITUDE
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
amplitude range: 10mV
p-p
——
16V
p-p
（
high resistance
），
5mV
p-p
——
8V
p-p
（
50
Ω）
display: 3 digits
amplitude error:
≤ ±
(5%+100 mV
p-p
)
（
high resistance, 1KHz, 1
—
16V
p-p
）
amplitude stability:
≤±
5%
（
1hr, high resistance, 1KHz,16V
p-p
）
flatness:
≤ ±
0 .5 d B
（≤
100KHz
）
,
≤±
0 .8 d B
（
100KHz
—
1MHz
）
,
≤±
2 d B
（
1MHz
—
2MHz
）
,
≤ ±
3 d B
（
2MHz
—
3MHz
）
,
（
less than 1Hz, the frequency amplitude is unst abl e
）
output impedance: 50
Ω（±
10%
）
TTL level output characteristic
：
low level:
＜
0.3V
；
high level:
＞
4.2V
（
high resistance
）
2-4.
2-4.
2-4.
2-4.
DRIFT
DRIFT
DRIFT
DRIFT
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
drift range: 0V
—— ±
6.4V
（
high resistance
），
0V
—— ±
3.2V
（
50
Ω
）
resolution:
50mV
（
high resistance
）
drift error:
≤ ±（
5%+100mV
）（
1hr, high resistance, 1KHz, 10V
p-p
）
2-5.
2-5.
2-5.
2-5.
MODULATION
MODULATION
MODULATION
MODULATION
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
CHARACTERISTIC:
amplitude modulation: AM
modulate waveform
：（
interior amplitude modulation
）
sine wave: 400Hz
±
10%, 1000Hz
±
10% 2 ranges
modulation depth
：
1%
——
100%
modulation source
：
inner modulation source
，
outer modulation source
outer modulation characteristic
：
input impedance
：
600
Ω
input level
：
the modulation depth is 50% at 0dB
input frequency response
：
100Hz
——
100KHz
（±
3dB
）
