Description
20 MHz DDS Function Generator from B&K Precision.
The BK4045B is a high-performance, 20 MHz DDS (direct digital synthesis) function generator with arbitrary waveform capability.
The device generates stable and precise sine, square, triangle, and arbitrary waveforms. It also provides variable output voltages from 0 to 10 Vpp into 50 Ω (up to 20 Vpp into open circuit), linear and logarithmic sweep, AM/FM modulation, a built-in counter, and a continuously variable DC offset that allows the output to be injected directly into circuits at the correct bias level.
Separate output amplitude and DC offset amplifiers let you set a large DC offset (e.g. ± 4.99 V ) with a small amplitude output signal (e.g. 10 mV). This is a feature that is typically found in more expensive generators.
The BK4045B combines a traditional DDS and a true arbitrary generator in one unit, giving you the benefits of both technologies. Using DDS technology, waveforms can be generated with high frequency resolution at a low price. Due to the inherent limitations of this architecture, not all points from the waveform memory are used, and points may be skipped at higher frequencies. This leads to significantly more jitter and higher distortions on non-repetitive waveforms. Sometimes small details of the waveforms stored internally will be missing from the output signal. The true arbitrary waveform section generates point-by-point waveforms with lower jitter, high resolution, and true representation of the required waveform.
Due to the arbitrary waveform capability of the BK4045B, the instrument is able to generate low-jitter square waves with greater edge stability. The improved signal integrity allows these generators to be used for simulating reliable clock signals, generating triggers, or validating serial data buses.
Product Features
- 12-bit, 50 MSa/s, 1k point arbitrary waveform generator
- Sine and square waveforms up to 20 MHz
- Triangle/ramp waveforms up to 2 MHz
- Bright colour display with waveform preview
- Linear and logarithmic sweep
- AM/FM modulation
- Independent output and DC offset amplifiers allow for small amplitude output signals with large DC offsets
- Low-jitter square wave generation
- Adjustable duty cycle
- Output ON/OFF button
- Internal/external triggering
- Gate and burst mode
- Built-in counter
- USB interface
- SCPI-compliant command set
- Arbitrary waveform editing software and remote control application software provided
- Short circuit and overvoltage protection on all inputs and outputs
Frequency Characteristics
|
Sine |
0.01 Hz to 20 MHz |
Square |
0.01 Hz to 20 MHz |
Triangle |
0.01 Hz to 2 MHz |
Resolution |
6 digits* or 10 mHz |
Accuracy (Sine) |
0.002% (20 ppm) at < 500 Hz: 0.001% + 0.006 Hz |
Output Characteristics
|
Amplitude Range |
10 mVpp to 10 Vpp (into 50 Ω);
20 mVpp to 20 Vpp (open circuit) |
Amplitude Resolution |
3 digits (1,000 counts) |
Amplitude Accuracy |
± 2% ± 20 mV of programmed output from 1.01 V – 10 V |
Flatness |
± 0.5 dB to 1 MHz
± 1 dB to 20 MHz |
DC Offset Range |
-4.99 V to 4.99 V (into 50 Ω) |
DC Offset Resolution |
10 mV, 3 digits |
DC Offset Accuracy |
± 2% ± 10 mV (into 50 Ω) |
Output Impedance |
50 Ω ± 2% |
Output Protection |
Protected against short circuit or accidental voltage applied to the main output connector |
Waveform Characteristics
|
Harmonic Distortion
(for sine wave at 5 Vp-p into 50 Ω) |
0 – 1 MHz, < -60 dBc
1 MHz – 5 MHz, <-50 dBc
5 MHz – 12 MHz, <-45 dBc
12 MHz – 20 MHz, <-50 dBc |
Square Rise / Fall Time |
≤ 20 ns (10% to 90% at full amplitude into 50 Ω) |
Duty Cycle |
Square: 20% - 80% to 2 MHz
Triangle: 1% - 99% in 1% steps, up to 200 kHz |
Symmetry Accuracy at 50% |
± 1% |
Jitter (Square) |
< 100 ps rms (cycle-to-cycle, typical) |
Arbitrary Waveform Characteristics
|
Sampling Rate |
20 ns to 50 s |
Vertical Resolution |
12 bits |
Accuracy |
0.001% |
Resolution |
4 digits |
Waveform Length |
2 to 1000 points |
Operating Modes
|
Continuous |
Output continuous at programmed parameters |
Triggered |
Output quiescent until triggered by an internal or external trigger, at which time one waveform cycle is generated to programmed parameters. Frequency of waveform cycle is limited to 1 MHz. |
Gate |
Same as triggered mode, except waveform is executed for the duration of the gate signal. The last cycle started is completed. |
Burst |
2-65535 cycles |
Trigger Source |
Trigger source may be internal, external, or manual. Internal trigger rate 0.1 Hz – 1 MHz (1 us – 10 s) |
Modulation Characteristics
|
Internal Amplitude Modulation |
0.1 Hz – 20 kHz sine, square, or triangle waveform |
External Amplitude Modulation |
5 Vp-p for 100% modulation, 10 kΩ input impedance |
Internal Frequency Modulation |
0.1 Hz – 20 kHz sine, square, or triangle waveform |
External Frequency Modulation |
5 Vp-p for 100% modulation, 10 kΩ input impedance |
Sweep Characteristics
|
Sweep Shape |
Linear or Logarithmic, up or down |
Sweep Time |
10 ms to 100 s |
Input and Output
|
Trigger IN |
TTL compatible
Maximum rate 1 MHz
Input impedance 1 kΩ
Minimum width > 50 ns |
Sync Out |
TTL pulse at programmed frequency; 50 Ω source impedance |
Modulation IN |
5 Vp-p for 100% modulation
10 kΩ input impedance
DC to > 20 kHz minimum bandwidth |
Counter Characteristics
|
Range |
50 Hz to 50 MHz |
Resolution |
Auto ranging, up to 8 digits |
Accuracy |
± 0.02% ± 2 digits |
Sensitivity |
25 mVrms typical |
General
|
Memory Storage |
20 instrument settings |
Arbitrary Memory |
1,000 points in flash memory |
Power Requirements |
100 V – 240 V AC ± 10%, 47-63 Hz |
Operating Temperature |
0 °C to 50 °C |
Storage Temperature |
-10 °C to 70 °C |
Humidity |
95% R.H. 0 °C to 30 °C |
Dimensions W x H x D |
213 x 88 x 210 mm |
Weight |
2.5 Kg |
Electromagnetic Compatibility |
Meets EMC Directive 2004/108/EC, EN55011, EN55082 |
Safety |
Meets Low Voltage Directive 2006/95/EC, EN61010 |
Included accessories |
Power cord, USB (type A to B) interface cable, certificate of calibration |
*For square wave, resolution is up to 4 digits when frequency is > 20 kHz.
Note: All specifications apply to the unit after a temperature stabilization time of 15 minutes over an ambient temperature range of 23 ºC ± 5 ºC.
Specifications are subject to change without notice.