onsemi DM81LS97AN

Overview

DM81LS97AN from Fairchild Semiconductor is a 20-pin PDIP-packaged octal 3-state non-inverting buffer with dual independent enable control (G1 for Y1–Y4, G2 for Y5–Y8), 5 V nominal supply, 15 ns typical propagation delay, and 80 mW typical power dissipation-used in bus interface and data routing applications within industrial control backplanes.

For engineers reviewing the DM81LS97AN datasheet, pinout, applications, or equivalent options, key selection considerations include dual-enable architecture, TTL-compatible input thresholds, 3-state output drive capability (±24 mA), and operation across 0°C to +70°C ambient temperature range.

Technical Context

The DM81LS97AN implements eight independent non-inverting buffers using low-power Schottky TTL technology. Each buffer has two inputs: one data (A1–A8) and one active-low enable (G1/G2), with G1 controlling outputs Y1–Y4 and G2 controlling Y5–Y8.

Outputs enter high-impedance state when either G1 or G2 is HIGH; both must be LOW for enabled operation. Logic behavior follows standard TTL voltage thresholds: VIH ≥ 2.0 V, VIL ≤ 0.8 V, VOH ≥ 2.7 V at I_OH = −5.2 mA, VOL ≤ 0.5 V at I_OL = 24 mA.

Key Specifications

Pinout & Package

DM81LS97AN is housed in a 20-lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" wide, with 2.54 mm pitch and through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state buffer applications.

Compared with SN74LS244N and 74ACT244PC, the DM81LS97AN uniquely delivers dual independent enables in a drop-in PDIP footprint while maintaining strict LS-TTL voltage compatibility-critical for retrofitting or maintaining legacy industrial hardware without redesign.

Availability

DM81LS97AN is available at Aetrix Electronics and suitable for industrial backplane bus interface, legacy PC expansion slot buffering, and microcontroller parallel port expansion requiring stable component supply and long-term obsolescence management.

Supply support for DM81LS97AN 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 semiconductor company specializing in analog and discrete power products, acquired by ON Semiconductor in 2016.

The DM81LS97AN belongs to Fairchild's legacy LS-TTL logic family, designed specifically for robust, low-power bus interfacing in commercial-temperature industrial and computing systems.

FAQ

What is the function of G1 and G2 on the DM81LS97AN?

G1 and G2 are active-low enable inputs that independently control two groups of outputs: G1 enables Y1–Y4, and G2 enables Y5–Y8. When either G1 or G2 is HIGH, its associated outputs go to high-impedance (Hi-Z). Both must be LOW for their respective outputs to reflect the A1–A8 inputs. This architecture allows segmented bus control not found in single-enable octal buffers like the SN74LS244N, making the DM81LS97AN especially useful in modular backplane designs where partial bus isolation is required.

Does the DM81LS97AN support 3.3 V logic inputs?

No, the DM81LS97AN is a TTL-family device with input thresholds defined for 5 V operation: V_IL ≤ 0.8 V and V_VIH ≥ 2.0 V. While it may function with 3.3 V CMOS outputs in some cases, guaranteed switching is only specified across the full 0–5 V range. For reliable 3.3 V interfacing, level-shifting circuitry or a CMOS-compatible alternative such as the 74ACT244PC is recommended. The DM81LS97AN itself requires a 4.75–5.25 V supply and is not 3.3 V tolerant.

What is the maximum output current rating for DM81LS97AN?

The DM81LS97AN specifies I_OL = 24 mA (LOW-level output current) and I_OH = −5.2 mA (HIGH-level output current) under recommended operating conditions. These values define worst-case drive capability into standard TTL loads and ensure reliable fan-out to ≥20 LS-TTL inputs. Exceeding these ratings risks parametric shift or accelerated wear; sustained short-circuit current is limited to −20 mA to −100 mA per output (per datasheet Note 6), with duration capped at one second.

Can DM81LS97AN replace DM81LS95AN in a design?

Yes, the DM81LS97AN can replace the DM81LS95AN in most applications because both share identical pinout, electrical specifications (15 ns delay, 80 mW power, same DC/AC characteristics), and non-inverting logic function. The key difference is enable architecture: DM81LS95AN uses a single 2-input NOR gate for all eight enables, whereas DM81LS97AN splits enables across G1 (Y1–Y4) and G2 (Y5–Y8). If the original design relies on shared enable control, the DM81LS97AN's dual-enable feature offers enhanced flexibility-but requires verifying that G1 and G2 are tied together or driven identically in the replacement layout.

Is DM81LS97AN RoHS compliant?

The original DM81LS97AN was manufactured prior to RoHS enforcement and uses leaded solder and packaging materials not compliant with EU Directive 2011/65/EU. Aetrix Electronics supplies only legacy-qualified units conforming to original Fairchild specifications, including Pb-containing PDIP packaging. For RoHS-compliant alternatives, consider modern equivalents such as the SN74LVC244A (with appropriate level-shifting), though pinout and voltage compatibility must be verified per application.