Texas Instruments SN74ACT7802-60FN

Overview

SN74ACT7802-60FN from Texas Instruments is a 1024 × 18-bit strobed FIFO memory IC with 30 ns access time, 16.7 MHz maximum clock frequency, programmable almost-full/almost-empty flag offset (default 256), and 68-pin plastic leaded chip carrier (PLCC) package. It serves as a high-speed asynchronous data buffer in digital communication interfaces between mismatched clock domains.

For engineers reviewing the SN74ACT7802-60FN datasheet, SN74ACT7802-60FN pinout, SN74ACT7802-60FN application, or SN74ACT7802-60FN equivalent, key selection criteria include strobed load/unload timing, 18-bit parallel I/O, status flag programmability, and industrial-temperature operation (0°C to 70°C).

Technical Context

The SN74ACT7802-60FN implements a dual-clock FIFO architecture with independent LDCK (load clock) and UNCK (unload clock) inputs, enabling true asynchronous read/write operations. Its internal 1024-word × 18-bit RAM array supports bit-parallel data transfer at up to 16.7 MHz with guaranteed 30 ns access time under CL = 50 pF.

Status logic generates EMPTY, FULL, HF (half-full), and AF/AE (almost-full/almost-empty) flags using configurable depth offsets; AF/AE offset is set via DAF control and D0–D8 inputs during reset, or defaults to 256. All outputs are 3-state with OE-controlled bus isolation.

Key Specifications

Pinout & Package

SN74ACT7802-60FN uses a 68-pin plastic leaded chip carrier (PLCC) package with J-lead configuration, 0.05-inch pitch, and body size 1.100 inch × 1.100 inch. Thermal resistance θ_JA is 39°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FIFO memory applications.

Compared with IDT7203L15TPG and SN74ACT7804-60FN, the SN74ACT7802-60FN uniquely balances 5-V compatibility, 18-bit native width, and 30 ns access in a single PLCC device-making it optimal for legacy industrial interfaces where voltage and pin count constraints preclude redesign.

Availability

SN74ACT7802-60FN is available at Aetrix Electronics and suitable for video frame buffering, serial-to-parallel conversion, telecom packet assembly, and DSP co-processor interfacing requiring stable component supply across long-lifecycle industrial programs.

Supply support for SN74ACT7802-60FN 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 global semiconductor leader specializing in analog, embedded processing, and logic solutions, with over 90 years of innovation in high-reliability components.

The SN74ACT7802-60FN belongs to TI's Widebus™ family of advanced CMOS logic devices, engineered for high-speed, low-power data buffering in industrial and communications infrastructure.

FAQ

What is the maximum operating frequency of the SN74ACT7802-60FN?

The SN74ACT7802-60FN supports a maximum clock frequency of 16.7 MHz for both LDCK and UNCK inputs, as specified in the timing requirements table for the -60 speed grade. This rating assumes operation within recommended conditions: VCC = 4.5 V to 5.5 V and TA = 0°C to 70°C. The part achieves this performance with guaranteed 30 ns access time and 45 ns maximum propagation delay to status flags.

How is the AF/AE flag offset programmed on the SN74ACT7802-60FN?

The AF/AE flag offset on the SN74ACT7802-60FN is programmed during reset using the DAF pin and D0–D8 inputs. To define a custom offset X, assert DAF low, then apply the 9-bit value to D0–D8 before pulsing RESET. Holding DAF high during RESET selects the default offset of 256. The SN74ACT7802-60FN does not retain offset settings across power cycles; reprogramming is required at each power-on reset.

Does the SN74ACT7802-60FN support cascading for increased word depth?

No, the SN74ACT7802-60FN does not support cascading in the word-depth direction. The datasheet explicitly states that cascading is permitted only in the word-width direction-for example, two SN74ACT7802-60FN devices can be combined to implement a 1024 × 36-bit FIFO, as shown in Figure 5. Depth expansion (e.g., 2048 × 18) requires a different part such as the SN74ACT7804-60FN, which shares pin compatibility but doubles memory depth.

What are the power supply requirements for reliable operation of the SN74ACT7802-60FN?

The SN74ACT7802-60FN requires a single 4.5 V to 5.5 V DC supply on VCC pins (multiple distributed VCC connections per datasheet pinout). Decoupling capacitors (0.1 µF ceramic per VCC–GND pair) are mandatory at each VCC pin location to suppress switching noise. Total supply current ICC is typically 400 µA in static operation and increases with clock activity; ∆ICC transient current peaks at 1 mA per input transition.

Can the SN74ACT7802-60FN be used in systems requiring extended temperature range?

No, the SN74ACT7802-60FN is characterized only for the commercial-industrial temperature range of 0°C to 70°C. It is not rated or tested for operation below 0°C or above 70°C. For extended temperature applications (e.g., –40°C to 85°C), designers must select alternative FIFO solutions or verify derated performance through application-specific testing, as TI does not guarantee functionality outside the published specification range for the SN74ACT7802-60FN.