Texas Instruments SN74AS763N

Overview

SN74AS763N from Texas Instruments is an octal buffer/line driver with complementary G and G̅ (active-low) enable inputs, open-collector outputs, 64-mA sink capability, 0.55-V VOL at IOL = 64 mA, and operation over 0°C to 70°C. It eliminates 3-state overlap protection in memory address bus driving applications.

For engineers reviewing the SN74AS763N datasheet, SN74AS763N pinout, SN74AS763N application, or SN74AS763N equivalent, this device is selected for high-current bus interfacing where dual active-low enables, low propagation delay (1–7 ns), and TTL-compatible input thresholds are required.

Technical Context

The SN74AS763N implements two independent 4-bit noninverting buffer sections, each controlled by complementary G/G̅ enables - enabling simultaneous activation of both halves or selective gating. Its open-collector outputs support wired-AND logic and direct connection to 5-V bus lines without pull-up resistors on the IC side.

Designed for AS (Advanced Schottky) logic family performance, it delivers tPHL as low as 1 ns and tPLH up to 20 ns under 50-pF load, with guaranteed 64-mA sink current per output and VOL ≤ 0.55 V at that level - exceeding standard ALS and matching industrial-grade drive requirements.

Key Specifications

Pinout & Package

SN74AS763N uses a 20-pin plastic DIP (N package), 300-mil width, with through-hole mounting and industry-standard pin spacing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal buffer with open-collector output applications.

Compared with SN74ALS763N and SN74F763N, the SN74AS763N uniquely combines 64-mA drive, sub-7 ns tPHL, and integrated complementary enables - making it the only option for high-reliability, high-fanout memory bus buffering without added logic.

Availability

SN74AS763N is available at Aetrix Electronics and suitable for memory address buffering, industrial I/O module selection, legacy bus expansion, and high-current digital interface applications requiring stable component supply and long-term obsolescence management.

Supply support for SN74AS763N 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

Texas Instruments is a U.S.-based semiconductor manufacturer founded in 1930, delivering analog, embedded processing, logic, and power management solutions globally with emphasis on reliability and industrial longevity.

The SN74AS763N belongs to TI's Advanced Schottky TTL logic family, designed specifically for high-speed, high-drive bus interfacing in memory and control subsystems of industrial, computing, and instrumentation equipment.

FAQ

What is the maximum sink current per output of the SN74AS763N?

The SN74AS763N supports up to 64 mA of continuous sink current per open-collector output, verified under VCC = 4.5 V and specified in the electrical characteristics table. This rating applies across the full commercial temperature range (0°C to 70°C) and enables direct driving of multiple TTL inputs or high-capacitance bus lines without external amplification. The SN74AS763N maintains VOL ≤ 0.55 V at this current level.

Does the SN74AS763N require external pull-up resistors on its outputs?

Yes, the SN74AS763N features open-collector outputs and requires external pull-up resistors to establish high-level logic states. Each output (1Y1–1Y4, 2Y1–2Y4) must be connected to VCC or another logic-high rail via a pull-up resistor sized according to bus capacitance and rise-time requirements. The SN74AS763N itself does not provide internal pull-ups or active high drivers.

How do the complementary G and G̅ inputs function on the SN74AS763N?

The SN74AS763N has two sets of complementary enable inputs: 1G/1G̅ for the first 4-bit section and 2G/2G̅ for the second. Both G and its complement must be driven simultaneously - e.g., G = LOW and G̅ = HIGH - to activate the corresponding outputs. Driving mismatched levels results in undefined output states. This architecture eliminates external inverters and prevents enable timing skew in the SN74AS763N.

Is the SN74AS763N pin-compatible with the SN74ALS763N?

Yes, the SN74AS763N is pin-compatible with the SN74ALS763N in the same N-package (20-pin DIP), sharing identical pinout, power connections, and signal assignments. However, they differ electrically: the SN74AS763N offers higher sink current (64 mA vs. 24 mA), faster propagation (1–7 ns vs. 2–11 ns), and tighter VOL spec. Board-level replacement is possible but requires validation of timing and drive margins in the SN74AS763N.

What is the operating temperature range for the SN74AS763N?

The SN74AS763N is characterized for commercial operation from 0°C to 70°C, as confirmed in the "recommended operating conditions" table of the SDAS067A datasheet. It is not rated for extended temperature ranges such as −40°C to 85°C or military −55°C to 125°C. Designs requiring wider thermal tolerance must consider SN54AS763 variants or alternative families, as the SN74AS763N specification is strictly limited to 0°C–70°C.