577-4C / 4-Channel Digital Delay Generator

The Model 577 Digital Delay/ Pulse Generator represents the latest in timing capabilities. Eight outputs, each configurable with its own pattern, its own trigger, its own gate, its own delay and width settings, make the 577 our most versatile instrument.



SKU: 577-4C Category:


Model 577-4C / 4-Channel Digital Delay Generator (250ps Delay & Width Resolution & 200pS Internal Channel to
Channel Jitter) RS-232, USB Standard

Model 577-4C  provides multi-channel 250 ps-resolution timing, delaying, gating, pulsing and synchronizing functions at an attractive price. In addition to the traditional digital delay and pulse generator modes, there are many practical modes of operation and features. For usefulness and value – there is nothing comparable.

Each channel provides both delays and widths – a 4-channel Model 577 provides the same delay and width functionality of competitive 8-channel units. The Model 577 is available in 4 and 8 channel configurations, with optional Ethernet, High Voltage and Dual Input Trigger options.

This Digital Delay/Pulse Generator, representing our finest in precision timing, provides precise delays and widths with 250 pS resolution for times up to 1000 seconds. Low jitter, with both internal clocks (50pS) and using an external trigger (800pS) gives users the timing needed to control many devices. This is particularly useful where several pulses or gate signals need to be delayed and timed with respect to each other or with a common trigger. You may even use one channel as a trigger reference for other channels, locking the timing delays when needed. There is much to learn about the Model 577, which offers much more, including a clock-divider, independent channel triggering, independent amplitudes/channel, delay and width control, and a LabVIEW 8 driver. Give us a call we are happy to discuss your applications.

Additional information

Weight 3.62 kg
Dimensions 13.97 × 26.67 × 20.95 cm

Channel Multiplexing

One of the more unique features of the Berkeley Nucleonics pulse generators is the ability to combine the timing of any or all channels together and output them out of any of the output BNCs. The multiplexing function (MUX) can be set through remote communications via a computer or from the front panel of most units.

Selectable Clock Reference

The Model 577 offers additional inputs and outputs for external clock synchronizing. Specify your input/output reference frequency (10 MHz to 100 MHz). Synchronize with the Mode Lock Oscillator of a laser, or phase lock multiple units with one clock.

Flexible Gating Options

The Model 577 is packed with gating options for almost any setup. You may gate with a channel or on any input. You may gate individual channels or gate all. Gate immediately (output inhibit) or gate after a pulse (pulse inhibit).

External Trigger Options

Select channels for internal/external triggering, or free-run. Triggered channels have flexible output choices: single pulse, burst at its clock rate, continuous pulse train or a series of on/off pulses (duty cycle). Contact us for custom wave trains or modes.

Individual Rates

Each channel can have individual channel rates (either T0 or any of the other channels…).


Forgot to save your settings? The Model 577 stores your setup configurations while powering down. Recall is automatic on power-up.

Dual Input Panel Connectors

The Model 577 offers two inputs for triggering or gating. You may specify electrical or optical input signals, and configure any trigger/gate combination. Use Trigger #2 to disable a triggered pulse train.

Front Panel High Voltage

Our modular architecture offers expanded functionality on user-selected front panel outputs. We offer a front panel High Voltage option ( adjustable from 35V, 200 mV steps) on 2, 4, 6 or all 8 channels.

Front Panel Optical

Many applications benefit from optical signals. For noisy environments or communications applications, we offer an LED output stage at the front panel. This modular option can be configured for 2, 4, 6 or 8 outputs at 820nm or 1300nm.

Combined Output Types

The outputs are configured in modules and output types are combined in pairs. Thus one may select optical, standard electrical or high voltage electrical in pairs for their instrument. For example, an 8 channel unit may have optical, standard electrical and high voltage outputs all on one instrument. Custom or additional output modules may be added as the need arises. See our handy Order Chart for all option configurations.

Field Programmability

The instrument can now have functions upgraded in the field, such as a special or custom feature upgrade via a fully programmable FPGA.

Custom Output Modes

Custom Modules such as the TZ-50 give users an expanded list of capabilities with the Model 577. One example is our TZ-50 option, which provides customers a TTL signal into 50 ohms expanded.

Negative Delay

Use the handy negative delay feature to reference one channel with respect to another channel in positive or negative time increments. By allowing a channel to reference another channel as its trigger, you can synchronize the channels with respect to each other.

Note that Negative Delay cannot trigger a channel before your initial trigger. It is intended to compliment the channel referencing option.



45V Rise, 50 Ohm, 10nS / Div

45V Rise Hi Z, 10nS / Div

***Due to the power consumption and heat restrictions, a maximum of four AT45 channels can be added on a single unit***


Model/Output 577 – 4C: 4 Independent Channels577 – 8C: 8 Independent Channels

Output Modules:

Standard AT20 Dual Channel, TTL/CMOS & Adjustable Output Module
Optional L82 Dual Channel, 820 nm Optical Output Module
L130 Dual Channel, 1300 nm Optical Output Module
AT35 Dual Channel, TTL/35 V High Voltage Output Module
AT45 Dual Channel, 45 V High and Low Impedance Voltage Output Module (limited to 4 channels)
TZ50 Dual Channel, High Current TTL/CMOS (for driving 50 ohm loads) & Adjustable Output Module
TZ35 Dual Channel, High Current TTL/CMOS (for driving 50 ohm loads) & 35 V High Voltage Output Module

Input Modules:

Standard IA15 Dual Channel, 1 Trigger / 1 Gate Input Module * Standard dual channel input module, providing one Trigger input and one Gate input. May be used with the Dual Trigger firmware Option to provide two independent Trigger sources.
Optional IL82 Dual Channel, 820 nm Optical Input Module
IL130 Dual Channel, 1300 nm Optical Input Module


Rate (T0 period) 0.001 Hz to 20.000 MHz (1000 s – 50 ns)
Resolution 5 ns
Accuracy 5 ns + (0.0001 x period)
T0 Period Jitter < 500 ps RMS
Time Base 200 MHz, low jitter PLL
Oscillator 50 MHz, 50 ppm crystal oscillator
System Output Modes Single, Normal, Burst, Duty Cycle, External Gate/Trigger
Burst Mode 1 to 10,000,000 pulses
Duty Cycle Mode 1 to 10,000,000 pulses ON and/or OFF
Pulse Control Modes Internally triggered, externally triggered or external gate.


Pulse Width Range 10 ns -1000 s
Width Accuracy 1 ns + [0.0001 x (width + delay)]
Width Resolution 50 ps
Pulse Delay Range 0 – 1000s
Delay Accuracy 1 ns + (0.0001 x delay)
Delay Resolution 250 ps
Jitter (channel to channel) < 250ps RMS
Output Multiplexor Any/all channels may be OR’d to any/all outputs.
Time Base Same as internal rate generator
Channel Output Modes Single, Normal, Burst, Duty Cycle
Burst Mode 1 to 10,000,000 pulses
Duty Cycle Mode 1 to 10,000,000 pulses ON and/or OFF
Wait Counts 1 to 10,000,000 pulses
Channel Control Modes Internally triggered or external gated. Each channel may be independently set to either mode.


USB USB 1.0 Standard
RS-232 DB-9 Connector using RS-232 Communications Standard
External Clock In 10 MHz – 100 MHz user selectable in discrete values
External Clock Out To or Ref out (10 to 100 MHz) user selectable in discrete values


DT-15 Dual Trigger Logic – provides atditional trigger via gate input
COM Extended Communications – Atds Ethernet & GPIB
SRM Single Rack Mount
DRM Dual Rack Mount


Storage 16 storage bins
Dimensions 10.5” x 8.25” x 5.5”
Weight 8 lbs
Power 100 – 240 VAC 50/60 Hz <3 A
Fuse (Qty 2) 3.15 A, 250 V Time-lag
Operation 0 – 40°C (32 – 104°F)
Transportation & Storage -40 – 70°C (-40 – 158°F)


TTL/Adjustable Dual Channel Output Module (Standard)
Output Impedance 50 ohm
Output Level 4.0 V typ into 1 kohm
Rise Time 2.8 ns typ (10% – 90%)
Slew Rate > 0.5 V/ns
Jitter 50 ps RMS channel to channel
Adjustable Mode
Output Level 2 V to 20 VDC into 1 kohm
1 V to 10 VDC into 50 ohm
Output Resolution 10 mV
Current 200 mA typical, 400 mA (short pulses)
Rise Time 15 ns typ @ 20V (high imp)
25 ns typ @ 10V (50 ohms)
(10% – 90%)
Slew Rate > 0.1V/ns
Overshoot < 1 V + 10% of pulse amplitude
Trigger/Gate Dual Input Module (Standard)
Trigger Input:
Function Generate individual pulses, start a burst or continuous stream
Rate DC to 1/ (200 ns + longest active pulse). Maximum of 5 MHz
Slope Rising or Falling
Threshold 200 mV to 15 VDC
Maximum Input 60 V Peak
Resolution 10 mV
Trigger Accuracy ±3% of Threshold Voltage
Impedance 5.3 kohm + 40pF
Rate DC to 20 MHz
Trigger Jitter < 20 ns RMS
Insertion Delay < 110 ns
Minimum Pulse Width 20 ns
Pulse Inhibit Delay < 150 ns RMS
Output Inhibit Delay < 100 ns RMS
Gate Input:
Mode Pulse inhibit or output inhibit
Polarity Active high/active low

Optical Outputs

Wavelength 820 nm or 1300 nm
Maximum Signal Rate 5 MBd
Maximum Link Dist. 1.5 km
Connector Type ST

Optical Inputs

Wavelength 820nm or 1300nm
Maximum Signal Rate 5 MBd
Maximum Link Dist. 1.5 km
Connector Type ST
Insertion Delay < 300 ns
Jitter < 1.4 ns RMS



Through a 50? load at 200 Hz
Output 5 V – 35 V
Setpoint Resolution 10 mV
Rise Time < 30 ns
Accuracy 500 mV
Max. Frequency (Internal & External) 4 kHz


Output Level 4.0 V typ into 50 Ohms
Rise Time 2.8 ns
Slew Rate 0.5 V/ns
Jitter – Channel to Channel 50 ps RMS
Adjustable Mode
Output Resolution 10 mV
Current 100 mA typ, 400 mA max (short pulses)
Slew Rate 0.1 V/ns


Amplitude 4 V – 45 V
Resolution 20 mV
Accuracy +/-1.5%
Rise Time < 2ns Typical 10%-90% (Low Z)

< 9ns Typical 10%-90% (High Z)

Fall Time < 9ns Typical 90%-10% (Low Z)

< 9ns Typical 90%-10% (High Z)

Frequency (Internal & External) DC – 100 kHz
Polarity – High Z (>10k) Active High or Active Low
Polarity – Low Z (50 Ohms) Active High Only
Pulse Width – High Z (>10k) 10 ns to DC
Pulse Width – Low Z (50 Ohms) 10 ns to 10 s
Current (maximum) 35 mA (High Z @10 ms width)
900 mA (Low Z @ 10 ms width)
Part Number Description 
P/N6923 Model 577 19″ Rack Mount
P/N6978 Model 577 19″ Dual Rack Mount