STMicroelectronics 74AC08TTR

Overview

74AC08TTR from STMicroelectronics is a quad 2-input AND gate IC in TSSOP-14 package, operating from 2V to 6V supply, delivering 4ns typical propagation delay at 5V, ±24mA symmetrical output drive, and 2µA max quiescent current at 25°C - used in high-speed digital logic interfacing, address decoding, and enable gating in industrial control systems.

For engineers reviewing the 74AC08TTR datasheet, 74AC08TTR pinout, 74AC08TTR application, or 74AC08TTR equivalent, key selection criteria include propagation delay matching, 50Ω transmission line drive capability, noise immunity (28% VCC), symmetrical tPLH/tPHL, and TSSOP-14 thermal and board-space constraints.

Technical Context

The 74AC08TTR implements four independent AND gates using sub-micron C2MOS technology with buffered outputs, enabling stable switching and high noise immunity. Its internal two-stage architecture includes input protection diodes (2kV ESD rated) and rail-to-rail input voltage tolerance (0 to VCC).

It supports operation across -55°C to +125°C with guaranteed AC performance at CL = 50pF and RL = 500Ω, and meets 50Ω transmission line driving requirements per output with matched |IOH|/IOL ≥ 24mA and balanced propagation delays (tPLH ≅ tPHL).

Key Specifications

Pinout & Package

TSSOP-14 package: 4.9–5.1 mm width, 6.25–6.5 mm length, 0.65 mm pitch, 0.5–0.7 mm lead protrusion, JEDEC MO-153 compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 2-input AND gate applications.

Compared with SN74AC08PW and 74LVC08APW, the 74AC08TTR uniquely combines 6V absolute max rating, 125°C operation, and 4ns propagation - making it optimal for mixed-voltage, high-reliability industrial designs where timing margin and thermal resilience are critical.

Availability

74AC08TTR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, medical infusion pump controllers, and test equipment signal routing requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for 74AC08TTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, digital, and mixed-signal ICs for industrial, automotive, and consumer markets.

The 74AC logic family targets high-speed, low-power TTL-compatible CMOS applications - emphasizing propagation delay consistency, noise immunity, and robustness in harsh electrical environments.

FAQ

Is the 74AC08TTR pin-compatible with standard 74LS08 or 74HC08?

Yes - it is pin- and function-compatible with 74-series 08 AND gates including 74LS08 and 74HC08 in TSSOP-14. However, its wider VCC range (2–6V), lower ICC, and faster tPD mean it can replace those parts directly but may require verification of fan-out and timing margins in legacy LS designs due to higher drive strength.

What is the maximum recommended trace length for 50Ω transmission line driving?

At 100MHz, the 74AC08TTR's 4ns tPD and 24mA drive support ≤15 cm (6 inches) of 50Ω microstrip on FR-4 with <10% signal degradation. For longer runs, add series termination at source or parallel termination at load to suppress reflections - verified via IBIS simulation using ST's official model.

Does the 74AC08TTR require external pull-up or pull-down resistors on unused inputs?

No - unused inputs may be tied directly to VCC or GND. The device has no internal pull-ups; however, floating inputs must be avoided to prevent increased ICC and potential oscillation. ST recommends hard-wiring unused inputs rather than relying on weak terminations, given its high noise immunity threshold (28% VCC).

Can the 74AC08TTR operate reliably at 1.8V supply?

No - the absolute minimum VCC is 2.0V per datasheet. At 1.8V, the device falls outside recommended operating conditions: VIH/VIL thresholds become undefined, tPD increases unpredictably, and output drive collapses below specification. For 1.8V systems, consider 74LVC08 or 74AUP08 families instead.