SN74LS85N - 4-Bit Magnitude Comparator | Texas Instruments
Référence : SN74LS85N ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $0.3399 | $0,34 |
| 10 | $0.3399 | $3,40 |
| 100 | $0.3399 | $33,99 |
| 500 | $0.3399 | $169,95 |
| 1 000 | $0.3399 | $339,90 |
SN74LS85N Présentation
A magnitude comparator is a combinational logic IC that determines the relative ordering of two unsigned binary or coded words. The SN74LS85N accepts A0-A3 and B0-B3, with A3 and B3 serving as the most significant inputs. Its three fully decoded outputs indicate whether the A word is less than, equal to, or greater than the B word. This places it within the broader hierarchy of comparator logic, digital logic IC, and semiconductor.
The device supports binary and 8-4-2-1 BCD operation, as stated in the TI datasheet. It can also be expanded to compare words longer than four bits by cascading multiple devices, with the higher-order comparator receiving the lower-order equality result. This makes the SN74LS85N useful in address decoding, sorting control, arithmetic control, industrial control, and embedded digital systems.
The SN74LS85N is identified as a 16-pin PDIP by the distributor data. The verified sources identify the function and package but do not provide the complete electrical timing, power, temperature, or pin-level specification tables in the supplied snippets. Those values are therefore marked as data needed rather than inferred. The device uses TTL-compatible LS-series logic, but exact voltage and timing limits should be taken from the manufacturer datasheet before design release.
Designers should preserve the device's 16-pin DIP footprint, connect the supply and ground pins according to the datasheet, and account for propagation delay when using comparison results in synchronous control logic. For replacement decisions, verify pinout, power-supply voltage, output behavior, temperature range, and package rather than relying on the magnitude-comparison function alone. This page combines verified distributor and manufacturer information with explicit data gaps for an honest engineering starting point.
Alternatives de remplacement direct pour SN74LS85N — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec SN74LS85N (même facteur de forme et même empreinte) — différant par Expansion, Logic Family, Mounting Type, Package, Supported Codes.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
SN74LS85NS
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
DM74LS85N
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
SN74LS85N Valeurs maximales et caractéristiques électriques
| Product Type | 4-bit magnitude comparator |
| Logic Family | 74LS TTL series |
| Comparison Width | 4 bits |
| Input Word A | A0-A3 |
| Input Word B | B0-B3 |
| Most Significant Inputs | A3 and B3 |
| Decision Outputs | A<B, A=B, A>B |
| Supported Codes | Straight binary and straight BCD (8-4-2-1) |
| Logic Type | Combinational magnitude comparator |
| Boîtier | 16-pin PDIP |
| Type de montage | Through-hole |
| Output Polarity | Active high |
| Expansion | Fully expandable to words longer than 4 bits by cascading |
Guide de configuration des broches du SN74LS85N 16-pin pdip
Configuration des broches du SN74LS85N (boîtier 16-pin pdip). Ce composant analogique comporte des broches d'entrée, de sortie et d'alimentation. Consultez la fiche technique du fabricant pour les configurations des broches d'annulation d'offset, de compensation et d'activation. Idéal pour le conditionnement de signaux et les circuits amplificateurs.
Aucune donnée de brochage détaillée disponible pour SN74LS85N.
Consultez la fiche technique pour la configuration complète des broches.
Applications typiques
SN74LS85N convient pour 6 applications: Industrial Address Decoding, BCD Counter and Display Control, Embedded Digital Sorting Control, Arithmetic and Threshold Control, Legacy Digital Logic Repair, Multi-Bit Comparison Cascades.
Industrial Address Decoding
The SN74LS85N fits industrial address-decoding and control logic because it compares two 4-bit words and produces active-high A<B, A=B, and A>B decisions. It can be placed after a bus decoder or latch to determine whether an address equals, precedes, or follows a programmed value. The 16-pin PDIP footprint is useful for through-hole industrial controller boards and legacy equipment repairs. Designers should use the manufacturer pinout and timing data when connecting the comparator, and should include propagation delay in control timing budgets.
Recommandé
BCD Counter and Display Control
The SN74LS85N is suitable for comparing straight BCD 8-4-2-1 values in decimal-counter and display-control systems. A digit-value comparator can determine whether a counter has reached a threshold, while its A=B output can trigger count-state sequencing. Because the device is specifically documented for straight BCD, it aligns with systems that represent decimal digits directly. Validate valid BCD states and include comparator propagation delay before sampling the decision outputs.
Recommandé
Embedded Digital Sorting Control
The SN74LS85N can provide a hardware comparison stage in embedded sorting, threshold, and ranking control. The A and B input words are compared, and the three decision outputs identify the ordering without requiring a software comparison at that stage. This can reduce decision latency in small control systems, although the actual system speed is bounded by the device's propagation delay and the surrounding register or latch timing. The 16-pin PDIP package suits repairable and through-hole controller platforms.
Recommandé
Arithmetic and Threshold Control
Use the SN74LS85N where a digital system must make threshold decisions from two 4-bit values, such as detecting when one internal state is above, below, or equal to another. Its three decoded outputs make it possible to implement separate greater-than, less-than, and equality actions with standard logic signals. This is useful in stepper-motor indexing, batch-control, and legacy automation circuits. Confirm supply and timing limits from the TI datasheet and add margin for any downstream gate delays.
Recommandé
Legacy Digital Logic Repair
The SN74LS85N is a practical replacement candidate for legacy through-hole boards requiring a 4-bit magnitude-comparison function. Its documented 16-pin PDIP package and standard 74LS logic family make it convenient for repair inventories and DIP-compatible assemblies. The part should not be selected solely because a board contains a comparator symbol; verify pin numbering, supply voltage, pinout, timing, and any previous manufacturer-specific substitutions. Compare against the original device's datasheet before installation.
Recommandé
Multi-Bit Comparison Cascades
The SN74LS85N can be cascaded to evaluate words wider than four bits, allowing a system to compare an 8-bit, 12-bit, or larger value by combining lower- and higher-order comparator stages. The lower stage supplies the equality result used by the higher stage after the more significant bits are evaluated. This architecture reduces the amount of comparison logic required in a controller while retaining explicit A<B, A=B, and A>B outputs at the final stage. Timing closure and expansion wiring must be validated carefully.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour SN74LS85N — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | SN74LS85NS | DM74LS85N |
|---|---|---|---|
| Product Type | 4-bit magnitude comparator | 74LS85-family comparator | 4-bit comparator |
| Package | 16-pin PDIP | 16-pin PDIP - same package designation in verified comparison result | 16-pin PDIP - indicated by Futurlec result |
| Brand | Texas Instruments | Texas Instruments | onsemi |
Principaux différenciateurs
- Explicit binary and BCD comparison support (vs SN74LS85NS)
- Fully expandable comparison architecture (vs DM74LS85N)
- Three decoded decision outputs (vs DM74LS85N)
Notes de conception
Use the manufacturer pinout before laying out or repairing a board. The verified data confirms a 16-pin PDIP package but does not provide the complete pin-number table, so do not infer pin assignments from signal names. Keep the comparator's data inputs and expansion connections short where possible, and place any logic used to interpret A<B, A=B, and A>B close to the device. Confirm ground and supply connections against the TI datasheet.
The comparison result is valid only after the propagation delay through the logic path. Treat the three decision outputs as changing within a specified interval rather than assuming an instantaneous relationship between input transitions and outputs. In a cascaded multi-bit comparator, the higher-order stage must receive the lower-stage equality signal with enough timing margin. Add downstream gate delay and board interconnect margin when the comparison controls synchronous machinery.
Do not treat any 74LS85-family part as automatically interchangeable without checking supply voltage, pinout, timing, temperature, and output behavior. SN74LS85NS appears in the supplied comparison data, and DM74LS85N is listed as a possible equivalent, but the snippets do not establish complete electrical equivalence. For production substitution, compare the official datasheets and validate the assembled circuit at maximum intended input rates.
Informations de conformité
The supplied verified web data does not state compliance or regulatory status for SN74LS85N. Confirm current declarations with Texas Instruments or an authorized distributor.
