This document describes the features of 3M's 3M Round Conductor Flat Cable .025″ 30 AWG Solid, TPE 3749 Series S. The cable allows for higher signal density, excellent transmission properties, mass termination, and zippable branching or discrete termination. It meets SCSI-3 Fast-20 characteristic impedance requirements. The cable is insulated with Thermoplastic Elastomer (TPE) and is gray in color.
The 3M 3749 Series round conductor flat cable is a .025" (0.635 mm) 30 AWG solid TPE‑insulated cable designed for high‑density interconnects. It offers a characteristic impedance of 90 Ω, low capacitance and inductance, and is suitable for SCSI‑3 Fast‑20 applications.
The sheet provides physical, electrical and environmental specifications, ordering dimensions, and warranty details. It also lists the UL file number, flammability rating, and temperature range for reliable use in a variety of installations.
| Conductor size | 30 AWG (0.254 mm) solid copper |
|---|---|
| Insulation material | Thermoplastic Elastomer (TPE) |
| Voltage rating | USA 150 V, Canada 150 V, EU <50 V |
| Characteristic impedance | 90 Ω unbalanced |
| Capacitance | 16.5 pF/ft (54.1 pF/m) |
| Inductance | 0.13 µH/ft (0.43 µH/m) |
| Propagation delay | 1.48 ns/ft (4.86 ns/m) |
| Velocity of propagation | 69 % of speed of light |
| Temperature rating | -40 °C to +105 °C |
| Flammability rating | USA VW‑1, Canada FT1 |
| UL file number | E42769 |
| Style number | 20297 |
The cable is rated for 150 V in the USA and Canada, and less than 50 V in the EU.
It has an unbalanced characteristic impedance of 90 Ω.
The cable can be used from –40 °C up to +105 °C.
The cable uses Thermoplastic Elastomer (TPE) insulation.