Data Sheet
Programmable DDS Function Generator Series
Models 4084, 4085, 4086 & 4087
Versatile modulation and trigger
capabilities
The generators provide extensive modulation
capabilities including AM, FM, FSK, PSK, pulse
modulation and linear/logarithmic sweep.
Internal and external modulation sources, as well
as internal, external and gated trigger sources are
supported. Modulation parameters can be set
precisely and are adjustable over a wide range.
For instance burst count is programmable in 1
burst increments up to 10000 bursts and burst
phase is adjustable in 0.1º increments.
B&K Precision® models 4084, 4085, 4086 and
4087 are high performance laboratory grade
synthesized function generators with a wide
frequency range of up to 120 MHz. Direct
digital synthesis (DDS) techniques are used to
create stable, accurate output signals for all 27
built-in standard and complex (arbitrary) waveforms. The generators produce high purity, low
distortion sine waves, square waves up to 40
MHz and provide a stable output of very small
signals down to the 1mV - 10mV range. The
instrument also provides a built-in 100 MHz
universal counter with frequency measurement
and totalize function.
The versatility and capabilities of this series make
it an ideal tool for many general-purpose test
and bench applications or for use in training and
education.
Fig.1 Single cycle burst, start phase=0º
Technical data subject to change
© B&K Precision Corp. 2012
w w w.bk prec ision.c om
Convenient user interface and
operation
You can adjust parameters via knob or numeric
keypad. Enter amplitude values directly in Vpp,
mVpp, Vrms, mVrms or dBm and display the
correct voltage by entering the actual output
configuration used (terminated with 50 Ohm or
open circuit). You can enter frequency in terms
of frequency or seconds using time values s, ms,
Hz, kHz or MHz. Submenus are used for
modulation modes and other complex functions.
The generators are fully programmable via the
standard RS232 interface, using SCPI commands. The instrument also provides 10 memories to store and recall instrument settings.
Additionally the current state is saved at power
off and can be restored at power up.
Programmable DDS Function Generator Series
Models 4084, 4085, 4086 & 4087
Specifications
Models
4084
4085
4086
4087
Frequ ency Characte ristics
1µHz ~ 20MHz 1µHz ~ 40MHz 1µHz ~ 80MHz 1µHz ~120MHz
Sine
1µHz ~ 20MHz 1µHz ~ 40MHz 1µHz ~ 40MHz 1µHz ~40MHz
Square
1µHz ~ 100kHz
All Other waveforms
Frequency Stability
±1x10-6 (22°C ±5°C)
Resolution
1µHz
Accuracy
≤ ± 5x10-6 (22°C ±5°C)
s, ms, Hz, kHz, MHz
Data entry Units
Wave for m Characteris tics
Main Waveforms (Sine, Square)
Amplitude resolution
12 bits
Sample Rate
200MSa/s
300MSa/s
Sine
Harmonic Distortion
≤ - 50dBc (frequency ≤ 5MHz)
≤ - 45dBc (frequency ≤ 10MHz)
of Sine Wave*
≤ - 40dBc (frequency ≤ 20MHz)
≤ - 35dBc (frequency ≤ 40MHz)
≤ - 30dBc (frequency > 40MHz)
THD *
0.1% (20Hz ~ 100kHz)
Square
Rise and fall time*
≤ 15ns
* = Note: Test conditions for harmonic distortion, sine distortion,
rise/fall time Output Amplitude 2Vp-p, Environmental temperature: 25°C±5°C
Others built-in waveforms
27 build-in standard and
Sine, Square, Triangle, Positive Ramp, Falling Ramp,
complex waveforms
Noise, Pulse, Positive Pulse, Negative Pulse, Positive
DC, Negative DC, Stair wave, Coded Pulse, Full wave
rectified, Half-wave rectified, Sine transverse cut, Sine
vertical cut, Sine phase modulation, Logarithmic,
Exponential, Half-round, Sinx/x, Square root, Tangent,
Cardiac, Earthquake, Combination
Waveform Length
4096 dots
Amplitude Resolution
10 bits
Pulse
Duty Cycle
0.1% ~ 99.9% (below 10kHz),
1% ~ 99% (10kHz ~ 100kHz)
Rise/Fall Time
≤ 100ns (Duty Cycle 20%)
DC signal characteristics
DC range
≤ 10mV – 10V (high impedance)
DC Accuracy
≤ ±5% of setting +10mV (high impedance)
Arbitrary
Non volatile memory
8 waveforms
Waveform length
8~16000 points
Amplitude resolution
10 bits
Frequency range
1µHz~100kHz
Sample rate
200MSa/s
A mplitu de Characteristics
Amplitude Range
For all models
Freq ≤ 40MHz: 2mV ~ 20Vpp (open circuit) , 1mV ~ 10Vpp (50Ω)
4084, 4085, 4086
Freq > 40MHz: 2mV ~ 4Vp-p (open circuit), 1mV ~ 2Vpp (50Ω)
4087
Freq > 40MHz: 0.1mV ~ 3Vpp (50Ω)
Resolution
2µVpp (open circuit), 1µVpp (50Ω)
Accuracy
± 1%+0.2mV (sine wave relative to 1kHz)
Stability
±0.5 % /3 hours
Flatness
For amplitude ≤ 2Vpp
±3% (freq≤ 5MHz), ±10% (5MHz2Vpp:
±5% (freq≤ 5MHz), ±10% (5MHz20MHz)
±1dBm (frequency>40MHz)
Output Impedance
50Ω
Output Units
Vpp, mVpp, Vrms, mVrms, dBm
DC Offset Characteristics
Offset Range (open circuit)
Freq ≤ 40MHz: ±10Vpk ac+dc (Offset ≤ 2 x pk - pk amplitude)
Freq > 40MHz: ±2Vpk ac+dc (Offset ≤ 2 x pk - pk amplitude)
Offset Resolution
2µV (open circuit), 1µV (50Ω)
Offset Error
±5% of setting +10mV (Ampl. ≤ 2Vpp into open circuit)
±5% of setting +20mV (Ampl. > 2Vpp into open circuit)
Modu lation
AM Characteristics
Carrier Waveforms
Modulation Source
Internal Modulating Waveform
Frequency of modulating signal
Distortion
Modulation Depth
Sine or Square
Internal or external
Sine, Square, Triangle, Rising/Falling Ramp
100µHz ~ 20kHz
≤ 2%
1% ~ 120%, 1% ~ 80% (frequency>40MHz,
Ampl > 2Vpp into open circuit)
± 5%+0.2% (100µHz < frequency ≤ 10kHz)
Modulation Error
±10%+2% (10kHz < frequency ≤ 20kHz)
Max. Amplitude of ext. input signal 3Vp-p (-1.5V~ +1.5V)
FM Characteristics
Carrier Waveforms
Sine or Square
Modulation Source
Internal or external
Sine, Square, Triangle, Rising/Falling Ramp
Internal Modulating Waveform
100µHz ~ 10kHz
Frequency of modulating signal
Max. 50% of carrier frequency for internal FM
Deviation
Max 100kHz (carrier frequency≥ 5MHz) for external
FM, with input signal voltage 3Vp-p (-1.5V~+1.5V)
FSK Characteristics
Carrier Waveform
Sine or Square
Internal or external trigger (external: TTL level,
Control ModeI
low level F1, high level F2)
FSK Rate
0.1ms ~ 800s
PSK Characteristics
Sine or Square
Carrier Waveform
Phase1 (P1) and Phase 2 (P2), range: 0.0 ~ 360.0°
PSK
0.1°
Resolution
PSK rate
0.1ms ~ 800s
Control Mode
Internal or external trigger (external: TTL level,
low level P1, high level P2)
Burst Characteristics
Waveform
Sine or Square
Burst Counts
1 ~ 10000 cycles
Time interval between bursts
0.1ms ~ 800s
Control Mode
Internal, single or external gated trigger
Frequency Sweep Characteristics
Waveform
Sine or Square
Sweep Time
1ms ~ 800s (linear), 100ms ~ 800s (log)
Sweep Mode
Linear or Logarithmic
Start/ Stop Frequency
Same as frequency range of Sine & Square
External trigger signal frequency DC ~ 1kHz (linear) DC~10Hz (log)
Control Mode
Internal or external trigger
I npu ts/ Outputs
Main Output
Impedance
50Ω
Protection
Short circuit and overload protected
Output MOD OUT
Frequency
100Hz ~ 20kHz
Waveform
Sine, Square, Triangle, Rising/Falling Ramp
Amplitude
5Vp-p ± 5%
Output Impedance
600Ω
Modulation IN
3Vpp = 100% Modulation
External Input Trig/FSK/Burst
Level - TTL
Univ ersal Cou nter, Ke y Specs*
Frequency Range
Frequency Measurement
1Hz ~ 100MHz
Totalize mode
50MHz max
* For full specification of the counter section, refer to online manual at www.bkprecision.com
Ge neral
AC Input
198~242V or 99~121V, Frequency: 47~ 63Hz
Power Consumption