The Tektronix TDS644B is a high-performance, 4-channel digital real-time oscilloscope designed for precise signal acquisition and analysis. Featuring an analog bandwidth of 500 MHz and a maximum real-time sample rate of 2.5 GS/s simultaneously across all four channels, it offers exceptional signal fidelity and transient capture capabilities. With standard 15,000-point record lengths, an 8-bit vertical resolution (extendable to over 11 bits with averaging), a high-resolution color display, and built-in advanced waveform math (including FFT), the TDS644B is a versatile instrument for demanding design, debugging, and testing environments.
Specifications
General
| Parameter | Value |
|---|---|
| Interfaces | GPIB (IEEE-488.2), RS-232, Centronics parallel port, VGA monitor output |
| Display | Color VGA display |
| Real-Time Clock | Standard (battery-backed, displays date and time) |
Physical
| Parameter | Value |
|---|---|
| Power Supply | 90 to 250 V AC, 45 to 440 Hz, 300 W maximum |
| Operating Temperature | 4 °C to 50 °C |
| Dimensions (W×H×D) | 445 mm × 193 mm × 471 mm |
| Weight | 14.1 |
Signal Acquisition System
| Parameter | Value |
|---|---|
| Number of Channels | 4 |
| Analog Bandwidth | 500 MHz |
| Calculated Rise Time | 700 ps |
| Maximum Real-Time Sample Rate | 2.5 GS/s (simultaneous on all 4 channels) |
| Vertical Resolution (A/D Converter) | 8-bit (greater than 11-bit with averaging) |
| Standard Record Length | 15,000 points per channel |
| Acquisition Modes | Sample, Envelope, Average |
| Channel Deskew Range | ±100 ns |
Vertical System
| Parameter | Value |
|---|---|
| Input Sensitivity Range | 1 mV/div to 10 V/div |
| Vertical Gain Accuracy | ±1.5% |
| Input Impedance | 50 Ω |
| Input Coupling | DC, GND |
| Maximum Input Voltage (50 Ω) | 5 V RMS |
| Channel-to-Channel Isolation | >100:1 at 100 MHz |
| Selectable Bandwidth Limits | 20 MHz and 150 MHz |
| Offset Range | ±1 V (1 mV/div to 99.5 mV/div), ±10 V (100 mV/div to 995 mV/div), ±24 V (1 V/div to 10 V/div) |
| Position Range | ±5 divisions |
Horizontal System
| Parameter | Value |
|---|---|
| Time Base Range | 200 ps/div to 10 s/div |
| Time Base Accuracy | ±100 ppm |
Trigger System
| Parameter | Value |
|---|---|
| Trigger Sources | Ch 1, Ch 2, Ch 3, Ch 4, AC Line, Auxiliary |
| Trigger Modes | Auto, Normal, Single |
| Trigger Coupling | DC, AC, HF Reject, LF Reject, Noise Reject |
| Trigger Types | Edge, Pulse, Logic, Video |
| Pulse Triggering | Glitch, Width, Runt, Slew Rate, Setup & Hold |
| Logic Triggering | Pattern, State |
| Video Triggering | NTSC, PAL, SECAM, Custom |
| Trigger Holdoff Range | 250 ns to 12 s |
Waveform Measurements & Analysis
| Parameter | Value |
|---|---|
| Automatic Measurements | Fully automated system supporting over 25 parameters |
| Waveform Math Operations | Addition, subtraction, multiplication, division |
| Advanced Math Functions | FFT, Integration, Differentiation |
| Limit Testing Capabilities | Waveform Pass/Fail Template Testing |
Storage & File Management
| Parameter | Value |
|---|---|
| Floppy Disk Drive Capacity | 3.5 in. DOS Format (1.44 MB / 720 KB) |
| Internal Setup Storage | Up to 10 front-panel setups |
| Internal Waveform Storage | 4 reference memory locations |
Environmental & Physical Characteristics
| Parameter | Value |
|---|---|
| Storage Temperature Range | -40 °C to +75 °C |
| Operating Humidity Range | Up to 95% RH at 40 °C |
| Operating Altitude | Up to 4,570 m (15,000 ft) |
| Non-Operating Altitude | Up to 12,190 m (40,000 ft) |
Power & Electrical
| Parameter | Value |
|---|---|
| Line Voltage Range | 90 to 250 V RMS (continuous), 47 Hz to 63 Hz; 90 to 132 V RMS, 47 Hz to 440 Hz |
| Maximum Power Consumption | 350 W |
Auxiliary Outputs & Inputs
| Parameter | Value |
|---|---|
| Calibrator Output Signal | 0.5 V into >= 50 kΩ, 1 kHz |
Calibration & Maintenance
| Parameter | Value |
|---|---|
| Warm-up Time | 20 minutes |
Options
| Parameter | Value |
|---|---|
| Option 2F | Advanced DSP Math (adds FFT, integration, and differentiation functions) |
| Option 13 | RS-232 and Centronics hardcopy interfaces |
| Option 05 | Video Trigger (provides NTSC, PAL, SECAM, and custom video triggering) |
| Option 1R | Rackmount kit (configured for standard 19-inch rack) |
Triggering Performance
| Parameter | Value |
|---|---|
| Trigger Level Range | ±12 divisions from center of screen |
| Trigger Sensitivity (Internal, DC Coupled) | 0.35 division from DC to 50 MHz, increasing to 1.2 division at 500 MHz |
Display
| Parameter | Value |
|---|---|
| Display Type | 7-inch Liquid Crystal Color Shutter (LCCS) CRT |
| Display Resolution | 640 × 480 pixels |
Technology
Digital Real-Time (DRT) Oscilloscope
Applications
Electronic circuit design, high-speed digital debugging, telecommunications testing, and general-purpose scientific research