Diodes Incorporated 74LVC240AT20-13

Overview

74LVC240AT20-13 from Diodes Incorporated is an octal buffer/line driver with dual 4-bit non-inverting channels, independent 3-state output-enable (OE) controls, 1.65V–3.6V supply operation, 5.5V-tolerant inputs, and IOFF partial power-down protection in TSSOP-20 package. It drives high-capacitance buses in mixed-voltage systems such as notebook I/O expansion and peripheral interface isolation.

For engineers reviewing the 74LVC240AT20-13 datasheet, 74LVC240AT20-13 pinout, 74LVC240AT20-13 application, or 74LVC240AT20-13 equivalent, key selection criteria include VCC operating range, IOFF-enabled power-down behavior, 24 mA drive strength at 3.0V, Schmitt-trigger input noise immunity, and TSSOP-20 thermal resistance (θJA = 74°C/W).

Technical Context

This device implements two independent 4-bit non-inverting buffers, each with dedicated OE control (Pin 1 and Pin 19), enabling selective channel disable without affecting the other. All inputs feature Schmitt-trigger action for robust noise rejection in noisy digital environments.

IOFF circuitry actively disables outputs during power-down, preventing backflow current when VCC = 0V while inputs or outputs are biased to 5.5V - critical for hot-swap and partial-power-down system architectures. Input voltage tolerance up to 5.5V allows direct interfacing with 5V logic while powered from 1.8V or 3.3V rails.

Key Specifications

Pinout & Package

TSSOP-20 package: 6.4 mm × 6.5 mm × 1.2 mm body, 0.65 mm lead pitch, exposed pad not present. RoHS-compliant, halogen-free "Green" construction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal buffer applications.

Compared with SN74LVC240APWR, the 74LVC240AT20-13 provides verified IOFF protection essential for power-gated systems; versus 74LVC240AQ20-13, it trades smaller size for easier hand-soldering and legacy TSSOP compatibility.

Availability

74LVC240AT20-13 is available at Aetrix Electronics and suitable for PC motherboard I/O expansion, notebook peripheral interface, and set-top box HDMI subsystems requiring stable component supply across multi-year production cycles.

Supply support for 74LVC240AT20-13 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design centers across Asia and manufacturing in China, Taiwan, and the U.S.

The 74LVC series targets low-voltage, mixed-signal interface applications - specifically engineered for 1.65V–3.6V operation with 5V-tolerant inputs and robust power-down safety in portable and embedded computing platforms.

FAQ

Can 74LVC240AT20-13 operate reliably at 1.65V supply?

Yes - the device is fully characterized down to 1.65V VCC per its Recommended Operating Conditions table. At this voltage, it delivers ≥4 mA output drive, supports 10 ns/V input transition rates, and maintains VIH/VIL thresholds scaled to 65%/35% of VCC. Propagation delay increases to 12.2 ns typical, but remains within specification.

What is the purpose of the IOFF feature, and how does it behave during power-down?

IOFF disables all outputs when VCC = 0V, blocking current flow from powered inputs or outputs into the unpowered IC. Measured IOFF leakage is ≤±10 μA at 5.5V bias - preventing latch-up or damage during hot-insertion or partial system shutdown. This behavior is guaranteed across -40°C to +125°C.

Are the inputs truly 5.5V-tolerant when VCC is 1.8V?

Yes - absolute maximum ratings confirm VI up to +7.0V, and Recommended Operating Conditions specify 0–5.5V input range regardless of VCC. Internal clamping diodes and oxide-thickness design ensure no degradation or leakage increase occurs when driving 5V signals into a 1.8V-powered device.

Does the TSSOP-20 package require thermal vias or special PCB layout for thermal management?

No - the TSSOP-20's θJA = 74°C/W is rated on a standard 4-layer FR-4 board with 2 oz copper and Diodes' recommended pad layout (AP02001). For continuous 500 mW dissipation, ambient must stay below +76°C; typical logic operation draws <1 mW, making thermal vias unnecessary in most applications.