onsemi MC74HC08AFR1

Overview

MC74HC08AFR1 from onsemi is a quad 2-input AND gate in high-performance silicon-gate CMOS technology, pinout-compatible with LS08 TTL logic. It operates from 2.0 V to 6.0 V, delivers ±25 mA output drive per pin, exhibits 10 LSTTL load drive capability, and supports industrial temperature range (–55 °C to +125 °C). It is used in digital control logic, address decoding, and enable gating in embedded microcontroller interfaces.

For engineers reviewing the MC74HC08AFR1 datasheet, pinout, applications, or equivalent options, key selection criteria include supply voltage flexibility (2–6 V), guaranteed propagation delay ≤19 ns at 4.5 V, input compatibility with both CMOS and LSTTL (with pullups), and Pb-free TSSOP-14 packaging for space-constrained PCBs.

Technical Context

The MC74HC08AFR1 implements four independent AND gates using standard CMOS logic architecture, with inputs tolerant of LSTTL levels when pullup resistors are applied. Each gate features symmetrical input thresholds (VIH = 3.15 V, VIL = 1.35 V at VCC = 4.5 V) and rail-to-rail output swing.

It complies with JEDEC Std No. 7A, supports high noise immunity, and integrates protection circuitry against electrostatic discharge. Unused inputs must be tied to VCC or GND; outputs are not internally clamped and must remain open when unused.

Key Specifications

Pinout & Package

TSSOP-14 package (Case 948G), 5.0 mm × 4.4 mm footprint, 0.65 mm pitch, thin-profile surface-mount design suitable for automated assembly and dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC08DR and 74VHC08M, the MC74HC08AFR1 offers optimal balance of industrial temperature range, TSSOP compactness, and proven AEC-Q100 qualification - making it preferred for new automotive and space-constrained industrial designs requiring long-term supply stability.

Availability

MC74HC08AFR1 is available at Aetrix Electronics and suitable for industrial control logic, automotive body electronics, and consumer appliance power sequencing requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for MC74HC08AFR1 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient innovation for automotive, industrial, cloud, medical, and IoT applications.

The MC74HC08AFR1 belongs to the 74HC logic family, designed for robust, low-power, pin-compatible upgrades to legacy TTL systems while supporting modern mixed-voltage board architectures.

FAQ

What is the maximum operating frequency of the MC74HC08AFR1?

The MC74HC08AFR1 does not specify a maximum clock frequency in its datasheet because it is a combinational logic device without an internal clock. Its usable toggle rate depends on propagation delay and load capacitance. With CL = 50 pF and VCC = 4.5 V, tPLH/tPHL ≤ 19 ns supports reliable operation up to approximately 26 MHz in repetitive gating applications.

Can the MC74HC08AFR1 interface directly with 3.3 V microcontrollers?

Yes, the MC74HC08AFR1 supports VCC down to 2.0 V and has VIH = 1.5 V min at VCC = 3.3 V, making it fully compatible with 3.3 V CMOS outputs. Its inputs recognize 3.3 V logic highs without level shifting, and its outputs swing rail-to-rail - delivering ~3.3 V high and ~0 V low when powered at 3.3 V.

Is the MC74HC08AFR1 qualified for automotive applications?

The MC74HC08AFR1 itself is not explicitly AEC-Q100 qualified; however, the NLV74HC08ADTR2G variant (same die, automotive-grade marking and screening) is AEC-Q100 qualified and PPAP capable. The FR1 suffix indicates TSSOP-14 packaging with standard industrial screening - suitable for non-safety-critical automotive subsystems where full qualification is not mandated.

What happens if an input is left floating on the MC74HC08AFR1?

Leaving an input floating on the MC74HC08AFR1 risks metastability, increased ICC, and erratic output behavior due to CMOS high-impedance inputs capturing noise. The datasheet mandates tying all unused inputs to either VCC or GND via direct connection or pullup/pulldown resistors - never left open - to ensure deterministic logic states and prevent shoot-through current.

Does the MC74HC08AFR1 require external decoupling capacitors?

Yes, the MC74HC08AFR1 requires a minimum 0.1 µF ceramic decoupling capacitor placed as close as possible (≤5 mm) between VCC (Pin 14) and GND (Pin 7). This suppresses supply rail transients caused by simultaneous output switching, preventing logic glitches and ensuring stable operation across the full –55 °C to +125 °C temperature range.