Name: Model 577 Digital Delay / Pulse Generator
Brand: Berkeley Nucleonics

Model 577 Digital Delay / Pulse Generator

A benchtop pulse and delay generator with four or eight independent channels, 250 ps resolution, and a repetition range from 0.001 Hz to 20 MHz. Deep gating and triggering, a field-programmable FPGA, and a wide choice of output modules make it a flexible synchronization hub for the lab.

Berkeley Nucleonics Corporation

1Overview

Verification notes. Values are drawn from the Model 577 datasheet and ordering guide. Confirm against the current released datasheet before quoting. Output-module figures (AT20, TZ50, AT35, TZ35, AT45, optical) depend on the modules ordered; the tables below reproduce the published values for each module. The Stanford DG535 / DG645 comparison is a positioning reference, not a specification.

The Model 577 is a benchtop precision pulse and delay generator. It offers four or eight independent output channels, each with 250 ps resolution on delay and pulse width. Delay ranges from 0 ns to 1000 s, pulse width from 10 ns to 1000 s, and repetition rate from 0.001 Hz to 20 MHz, with timing accuracy of 1 ns plus 0.0001 times the set value.

Beyond raw timing, the 577 is built for synchronization. Any channel can be OR'd to any output, gating can be applied per channel or across the system, and burst, nested-burst, and duty-cycle modes cover repetitive sequencing. A field-programmable FPGA keeps the feature set current, and 16 memory locations store full instrument configurations.

2Key Features

Four or eight independent output channels
250 ps resolution on delay and pulse width
Delay range 0 ns to 1000 s, pulse width 10 ns to 1000 s
Repetition rate 0.001 Hz to 20 MHz
Accuracy of 1 ns + 0.0001 times the setpoint
Channel-to-channel jitter below 50 ps RMS
Burst, nested-burst, and duty-cycle modes
Channel multiplexing: OR any channel to any output
USB and RS-232 standard; optional Ethernet and GPIB
External clock sync, 10 MHz to 100 MHz
Field-programmable FPGA and 16 memory locations

3Channels & Timing Architecture

The Model 577 ships as a four-channel (577-4C) or eight-channel (577-8C) instrument. A single internal rate generator sets the system period (T0), and each channel runs its own delay, width, and output mode against that time base. Because any or all channels can be OR'd to any or all output BNCs, a single pulse can be steered to several outputs, or several channels can be combined onto one.

The time base is a 200 MHz low-jitter PLL driven from a 50 MHz, 50 ppm crystal oscillator, with selectable external clock reference from 10 MHz to 100 MHz. Negative delay, individual per-channel rates, and per-channel gating give the instrument the flexibility to act as the timing backbone of a multi-instrument setup.

Model 577 rear panel — Rear panel. Channel output BNCs, trigger and gate inputs, and clock reference connections.

4Specifications

Internal Rate Generator

Parameter	Value
Rate (T0 period)	0.001 Hz to 20.000 MHz (1000 s to 50 ns)
Resolution	5 ns
Accuracy	5 ns + (0.0001 x period)
T0 period jitter	< 50 ps RMS
Time base	200 MHz low-jitter PLL
Oscillator	50 MHz, 50 ppm crystal
System output modes	Single, normal, burst, duty cycle, external gate/trigger
Burst mode	1 to 10,000,000 pulses

Timing Generator

Parameter	Value
Pulse width range	10 ns to 1000 s
Width accuracy	1 ns + 0.0001 x width setting
Width resolution	250 ps
Pulse delay range	0 to 1000 s
Delay accuracy	1 ns + 0.0001 x delay setting
Delay resolution	250 ps
Jitter (channel to channel)	< 50 ps RMS
Output multiplexer	Any/all channels may be OR'd to any/all outputs
Channel output modes	Single, normal, burst, duty cycle

Standard Output Module (AT20)

Parameter	TTL/CMOS Mode	Adjustable Mode
Output / source impedance	High impedance	—
Output level	4.0 V typ into 1 kΩ	2 V to 20 VDC into 1 kΩ or 1 V to 10 VDC into 50 Ω
Rise time (10% to 90%)	< 3 ns (1.5 ns typ)	15 ns typ @ 20 V into Hi-Z (25 ns typ @ 10 V into 50 Ω)
Jitter	< 50 ps RMS channel to channel	—
Amplitude resolution	—	10 mV
Current	—	200 mA typ, 400 mA (short pulses)
Slew rate	—	0.1 V/ns

Optional 45 V Output Module (AT45)

Parameter	Value
Amplitude	4 V to 45 V
Resolution	20 mV
Accuracy	±1.5%
Rise time (10% to 90%)	< 2 ns into 50 Ω typ / < 9 ns into Hi-Z typ
Frequency (internal and external)	DC to 100 kHz
Max current	35 mA (Hi-Z @ 10 ms width) / 900 mA (50 Ω @ 10 ms width)
Note	Maximum of four AT45 channels per unit

Physical and Environmental

Parameter	Value
Dimensions	10.5 x 8.25 x 5.5 in [267 x 210 x 140 mm]
Weight	8 lbs [3.6 kg]
Power	100 to 240 VAC, 50/60 Hz, < 3 A
Operating temperature	32 to 104 °F [0 to 40 °C]
Memory storage	16 memory locations
External clock in/out	10 MHz to 100 MHz, user selectable
Warranty	Full 3-year warranty with lifetime no-cost firmware upgrades

5Triggering & I/O

The standard electrical input module (IA15) handles trigger and gate functions. The trigger input generates individual pulses, starts a burst, or starts a continuous stream; the gate input applies pulse inhibit or output inhibit, with active-high or active-low polarity. An optional dual-trigger input (DT15) adds a second input.

Parameter	Trigger Input (IA15)
Rate	DC to 1/(200 ns + longest active pulse), max 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	1.2 kΩ
Trigger jitter	< 800 ps RMS
Insertion delay	< 110 ns
Minimum pulse width	20 ns

USB 1.0 and an RS-232 DE-9F connector are standard. Optical input and output modules (820 nm or 1300 nm, ST connector, up to 5 MBd over 1.5 km) are available for electrically isolated links.

6Options & Configurations

Channel output modules are selected per pair (A&B, C&D, E&F, G&H), so a single instrument can mix output types across its channels.

Channel output modules

AT20: TTL (Hi-Z) / 2 to 20 V adjustable (Hi-Z), standard
TZ50: TTL (50 Ω) / 2 to 20 V adjustable (Hi-Z)
AT35: TTL (Hi-Z) / 5 to 35 V adjustable (50 Ω)
TZ35: TTL (50 Ω) / 5 to 35 V adjustable (50 Ω)
AT45: 4 to 45 V adjustable (Hi-Z / 50 Ω)
L82: 820 nm optical output; L130: 1300 nm optical output

Trigger / gate input and system options

IA15 electrical 15 V adjustable threshold input, standard
IL82 / IL130 optical input
DT15 dual trigger input
COM: add LAN and GPIB port
US 115 V or EU 230 V power cord
P/N6923 single rack mount; P/N6978 dual rack mount

7Applications

Laser systems
Research applications
Synchronization across multiple instruments
Test setups
Particle image velocimetry (PIV)

Oscilloscope capture of four channels multiplexed into a single combined output — Channel multiplexing on a scope. Active-high outputs from channels A, B, and C combine into a single active-low waveform, one of many configurations the channel modes allow.

Block diagram of a synchronizer delay generator driving eight independent channels with per-channel delay and pulse width — Inside the 577. A single synchronizer drives up to eight independent channels, each with its own delay and pulse width at 250 ps resolution.

8Ordering / In the Box

Specify channel count and the output module for each channel pair when ordering, along with any input, communication, and rack-mount options. The instrument ships with power cord and a calibration certificate, and carries a full 3-year warranty with lifetime no-cost firmware upgrades.

Item	Detail
577-4C	Four independent output channels
577-8C	Eight independent output channels

To configure or quote, contact Berkeley Nucleonics at info@berkeleynucleonics.com or 800-234-7858.