Texas Instruments SN65240P

Overview

SN65240P from Texas Instruments is a quadruple unidirectional transient voltage suppressor (TVS) designed for ESD protection of USB full-speed and low-speed ports. It features 6.5-V minimum breakdown voltage, 35-pF typical input capacitance, ≤1-µA leakage at 6 V, −40°C to 85°C operating range, and PDIP-8 package. It protects USB transceivers in host, hub, and peripheral interfaces against 15-kV HBM ESD events.

For engineers reviewing the SN65240P datasheet, SN65240P pinout, SN65240P application, or SN65240P equivalent, this page delivers verified electrical parameters, validated PDIP-8 pin mapping, confirmed USB 1.1 (12 Mbps) compatibility, and two field-validated alternative parts with documented functional trade-offs.

Technical Context

The SN65240P integrates four independent unidirectional TVS diodes in a single PDIP-8 package, each with Zener-triggered clamping action above 6.5 V and forward-conduction behavior below ground for negative transients. Its structure uses a bipolar transistor–Zener hybrid topology enabling precise 6.5-V breakdown and fast response to sub-nanosecond ESD pulses.

It operates without external power, relying solely on transient voltage thresholds to switch between high-impedance standby mode and low-impedance shunt mode. All four channels share common ground pins (pins 1, 3, 5, 7), ensuring low-inductance return paths critical for effective ESD energy diversion during IEC 61000-4-2 events.

Key Specifications

Pinout & Package

SN65240P uses an 8-pin plastic dual in-line package (PDIP) with 0.3-inch body width and 0.1-inch lead pitch. The package includes four dedicated ground pins (1, 3, 5, 7) to minimize inductance in ESD current return paths.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient suppression applications.

Compared with SN65240P, SN65240PWR offers surface-mount scalability but demands stricter process control, while SN75240P sacrifices thermal margin for lower unit cost-neither is pin-compatible drop-in replacement without verifying ambient and assembly constraints.

Availability

SN65240P is available at Aetrix Electronics and suitable for USB full-speed host ports, industrial PLC service interfaces, and embedded peripheral designs requiring stable component supply across long-lifecycle programs.

Supply support for SN65240P includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The SNx52x0 family was developed specifically to provide robust, low-capacitance ESD protection for USB 1.1 interfaces, targeting designers needing certified system-level immunity without compromising signal integrity.

FAQ

What is the maximum data rate supported by SN65240P?

The SN65240P supports USB full-speed operation up to 12 Mbps. Its 35-pF typical input capacitance limits use to USB 1.1 signaling; it is not suitable for USB 2.0 high-speed (480 Mbps) due to excessive signal distortion and eye closure. Designers must verify timing margins using IBIS models if operating near the 12-Mbps limit.

Does SN65240P require an external power supply?

No, SN65240P does not require an external power supply. It is a passive transient suppressor composed of integrated p-n junctions and bipolar structures that activate only when transient voltages exceed the 6.5-V breakdown threshold. This eliminates supply rail routing, reduces board space, and avoids potential power sequencing issues in USB designs.

Can SN65240P protect both D+ and D− lines simultaneously?

Yes, SN65240P protects both D+ and D− lines simultaneously via dedicated channels: pin 2 (A) connects to D+, pin 4 (B) connects to D−, and both reference the same local ground network through pins 1, 3, 5, and 7. This dual-channel configuration maintains differential signal integrity while providing independent clamping for each line during asymmetric ESD events.

What is the standoff voltage specification for SN65240P?

The standoff voltage for SN65240P is 6 V minimum, defined as the maximum continuous working voltage the device can withstand without entering conduction. This value ensures reliable operation across the full USB 5-V nominal supply range while maintaining sufficient margin below the 6.5-V minimum breakdown voltage to prevent false triggering during normal signal swings.

Is SN65240P compliant with IEC 61000-4-2 ESD testing?

SN65240P meets IEC 61000-4-2 system-level ESD requirements when implemented per TI's layout guidelines: placement within 2 mm of the USB connector, direct connection of all four GND pins to a solid ground plane, and use of multiple vias. Its ±15-kV HBM rating correlates to Level 4 system-level performance, but final compliance depends on board-level design-not just the SN65240P alone.