BK Precision 4087, 4085 Datasheet

Models 4084, 4085,
4086 & 4087

Programmable DDS Function
Generator Series

Specifications subject to change without notice

Data Sheet

Programmable DDS Function
Generator Series

Models 4084, 4085, 4086 & 4087

The 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.

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.

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.

Fig1 Single cycle burst, start phase=0º

B&K Precision Corporation

22820 Savi Ranch Parkway, Yorba Linda, CA92887
Tel: [phone], Fax: [phone]
www.bkprecision.com

Frequency Characteristics

Sine 1µHz ~ 20MHz 1µHz ~ 40MHz 1µHz ~ 80MHz 1µHz ~120MHz
Square 1µHz ~ 20MHz 1µHz ~ 40MHz 1µHz ~ 40MHz 1µHz ~40MHz
All Other waveforms 1µHz ~ 100kHz
Frequency Stability ±1x10-6(22°C ±5°C)
Resolution 1µHz
Accuracy ≤ ± 5x10-6(22°C ±5°C)
Data entry Units s, ms, Hz, kHz, MHz

Waveform Characteristics

Main Waveforms (Sine, Square)

Amplitude resolution 12 bits
Sample Rate 200MSa/s 300MSa/s
Sine

Harmonic Distortion ≤ - 50dBc (frequency ≤ 5MHz)
of Sine Wave* ≤ - 45dBc (frequency ≤ 10MHz)

≤ - 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

Amplitude 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% (5MHz<freq≤ 40MHz)

For amplitude >2Vpp: ±5% (freq≤ 5MHz), ±10% (5MHz<freq≤ 20MHz)

±20% (frequency>20MHz)

±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)

Modulation

AM Characteristics

Carrier Waveforms Sine or Square
Modulation Source Internal or external
Internal Modulating Waveform Sine, Square, Triangle, Rising/Falling Ramp
Frequency of modulating signal 100µHz ~ 20kHz

models

4084 4085 4086 4087

Specifications

Specifications (Cont.) Models 4084, 4085, 4086 & 4087

Distortion ≤ 2%
Modulation Depth 1% ~ 120%, 1% ~ 80% (frequency>40MHz,

Ampl > 2Vpp into open circuit)

Modulation Error ± 5%+0.2% (100µHz < frequency ≤ 10kHz)

±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
Internal Modulating Waveform Sine, Square, Triangle, Rising/Falling Ramp
Frequency of modulating signal 100µHz ~ 10kHz
Deviation Max. 50% of carrier frequency for internal FM

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
Control ModeI Internal or external trigger (external: TTL level,

low level F1, high level F2)

FSK Rate 0.1ms ~ 800s

PSK Characteristics

Carrier Waveform Sine or Square
PSK Phase 1 (P1) and Phase 2 (P2), range: 0.0 ~ 360.0°
Resolution 0.1°
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

Inputs/ 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

Universal Counter, Key Specs*

Frequency Range

Frequency Measurement 1Hz ~ 100MHz

Totalize mode 50MHz max

* For the full specification of the counter section refer to www.bkprecision.com
General

Power Supply 198~242V or 99~121V, Frequency: 47~ 63Hz
Power Consumption <35VA
State Storage Memory

Storage Parameters frequency, amplitude, waveform, DC offset values,

modulation parameters

Storage Capacity 10 user configurable stored states
Dimensions (W x H x D) 10” x 3.93” x 14.56” (255 mm x 100 mm x 370 mm)
Weight 6.6lbs (3 kg)
Remote Interface RS232
Safety designed according to EN61010
EMC tested according to EN55022, EN55024, EN61326, EN601000

NOTE: Specifications and information are subject to change without notice. Please visit
www.bkprecision.com for the most current product information.

Accessories Included BNC to alligator cable, BNC to BNC cable,

RS232 communication cable, power line cord,

test report, spare fuse

Accessories

One Year Warranty