onsemi DM74LS08M

Overview

DM74LS08M from Fairchild Semiconductor is a quad 2-input TTL AND gate IC in 14-lead SOIC (M14A) package, operating at VCC = 4.75–5.25 V, with propagation delays of 3–18 ns, output drive capability of ±0.4 mA (IOH) / 8 mA (IOL), and rated for 0°C to +70°C industrial temperature range. It performs discrete logic gating in combinational digital control circuits.

For engineers reviewing the DM74LS08M datasheet, pinout, applications, or equivalent options, key selection considerations include guaranteed TTL-level input thresholds (VIL = 0.8 V, VIH = 2.0 V), output voltage compliance (VOL ≤ 0.5 V at IOL = 8 mA), SOIC-14 mechanical compatibility, and legacy LS-family timing behavior under 5 V supply.

Technical Context

The DM74LS08M implements four independent AND gates using low-power Schottky (LS) TTL technology, with bipolar transistor-based input stages and totem-pole outputs. Each gate accepts standard TTL-compatible inputs and delivers rail-referenced HIGH/LOW outputs without external pull-ups.

It operates strictly within the 5 V nominal supply domain, with defined absolute maximum ratings (e.g., 7 V supply, −1.5 V input clamp) and recommended conditions ensuring stable logic margins across temperature. No internal ESD protection diodes or level-shifting circuitry is present.

Key Specifications

Pinout & Package

DM74LS08M is housed in a 14-lead Small Outline Integrated Circuit (SOIC) package per JEDEC MS-120, 0.150" narrow body, with gull-wing leads and 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS08DR and MC74LS08DG, the DM74LS08M offers identical functional behavior and SOIC-14 mechanical fit but reflects Fairchild's specific AC characterization methodology-making it suitable for legacy system continuity where original-bill-of-materials fidelity is mandated.

Availability

DM74LS08M is available at Aetrix Electronics and suitable for industrial control logic, test equipment sequencing, legacy system repair, and education & prototyping requiring stable component supply and long-term obsolescence management.

Supply support for DM74LS08M 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

Fairchild Semiconductor was a U.S.-based analog and discrete semiconductor manufacturer, acquired by ON Semiconductor in 2016, known for foundational TTL, MOS, and power device families.

The DM74LS08M belongs to the 74LS logic family, designed specifically for high-speed, low-power digital control in cost-sensitive commercial and industrial systems using 5 V rails.

FAQ

What logic family does the DM74LS08M belong to, and how does it differ from standard 7408?

The DM74LS08M belongs to the low-power Schottky (74LS) TTL logic family. Unlike the original 7408 (standard TTL), it uses Schottky clamping to reduce propagation delay and power consumption. The DM74LS08M delivers typical tPLH/tPHL of 10 ns versus 20+ ns for 7408, while drawing less supply current-making it suitable for higher-speed, lower-heat digital systems where the DM74LS08M replaces older variants without changing logic function.

Is the DM74LS08M pin-compatible with other 14-pin quad 2-input AND gate packages?

Yes-the DM74LS08M shares identical pinout with SN74LS08, MC74LS08, and 74LS08 variants in SOIC-14 (M14A) packaging. All follow the standard 74xx logic pin assignment: VCC on pin 14, GND on pin 7, and gate inputs/outputs mapped consistently across manufacturers. This ensures direct substitution in SOIC-14 footprints where the DM74LS08M is specified.

What are the absolute maximum ratings for the DM74LS08M, and why do they matter in circuit design?

The DM74LS08M has absolute maximum ratings of 7 V supply voltage, 7 V input voltage, and −1.5 V input clamp voltage. Exceeding these-even briefly-can cause permanent junction damage. These limits define safe handling boundaries during hot-plug, ESD events, or transient coupling. Designers must ensure the DM74LS08M operates only within its recommended 4.75–5.25 V VCC range and use series resistors or clamps if interfacing with non-TTL sources.

Can the DM74LS08M drive LEDs directly, and what current-limiting considerations apply?

The DM74LS08M can sink up to 8 mA per output (IOL = 8 mA), sufficient to drive low-current indicator LEDs with appropriate series resistance. For a red LED (VF ≈ 1.8 V) at 5 V supply, a 390 Ω resistor limits current to ~8.2 mA-within spec. However, the DM74LS08M cannot source significant current (IOH = −0.4 mA), so LEDs must be connected anode-to-VCC and cathode-to-output for reliable operation using the DM74LS08M.

Does the DM74LS08M require external pull-up or pull-down resistors on unused inputs?

Yes-unused inputs on the DM74LS08M must be terminated to VCC or GND to prevent floating nodes that cause excessive supply current, oscillation, or unpredictable output states. TTL inputs draw current when LOW; leaving them open results in indeterminate logic levels. Tying unused inputs to VCC via 1 kΩ resistors or directly to GND ensures stable operation and avoids unintended current paths in the DM74LS08M.