Texas Instruments SN74V245-10PAG

Overview

SN74V245-10PAG from Texas Instruments is a 4096 × 18-bit synchronous first-in, first-out (FIFO) memory IC designed for high-speed DSP-to-processor and DSP-to-analog front-end buffering. It delivers 7.5-ns read/write cycle time, 3.3-V V_CC with 5-V input tolerance, and supports both standard and first-word fall-through (FWFT) timing modes in industrial temperature range (0°C to 70°C).

For engineers reviewing the SN74V245-10PAG datasheet, SN74V245-10PAG pinout, SN74V245-10PAG application, or SN74V245-10PAG equivalent, this device serves as a glueless interface to TMS320 DSPs, enables depth/width expansion via XI/XO daisy-chaining, and provides programmable almost-empty/full flags with default offsets of 127 words.

Technical Context

This FIFO employs dual independent synchronous ports with asynchronous or coincident RCLK/WCLK operation, enabling flexible clock domain bridging. Its internal architecture includes separate read/write pointers, offset registers for PAE/PAF flag programming, and dedicated expansion logic for daisy-chain depth expansion using FL, RXI/RXO, and WXI/WXO pins.

Flag behavior is mode-dependent: FWFT mode uses OR/IR outputs (output ready/input ready), while standard mode uses EF/FF (empty/full); HF (half-full), PAE, and PAF are updated synchronously on RCLK or WCLK edges depending on configuration selected at reset via FL/RXI/WXI.

Key Specifications

Pinout & Package

Packaged in a 64-pin thin quad flat package (TQFP), the SN74V245-10PAG features 18-bit bidirectional data paths, dual independent clocks (RCLK/WCLK), and dedicated expansion/control pins including FL, LD, RS, OE, REN, and WEN.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V2105L10PF and ICS650G-03LFT, the SN74V245-10PAG uniquely combines 5-V input tolerance, FWFT mode configurability via FL pin, and user-programmable PAE/PAF offsets-making it optimal for mixed-voltage DSP systems requiring dynamic buffer control.

Availability

SN74V245-10PAG is available at Aetrix Electronics and suitable for telecom data buffering, DSP-based audio processing, industrial vision sensor interfaces, and network protocol acceleration requiring stable component supply and long-term industrial lifecycle support.

Supply support for SN74V245-10PAG 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 digital signal processing technologies, with over 50 years of innovation in high-performance data-path components.

The SN74V245-10PAG belongs to TI's DSP-SYNC™ FIFO family, engineered specifically to eliminate glue logic between TMS320 DSPs and peripheral interfaces while delivering deterministic low-latency buffering for real-time signal processing systems.

FAQ

What is the memory organization and maximum operating frequency of the SN74V245-10PAG?

The SN74V245-10PAG implements a 4096 × 18-bit synchronous FIFO array, providing 73,728 bits of buffered storage. It supports read/write cycle times of 7.5 ns, enabling reliable operation at up to 133 MHz clock frequency. This performance is validated across the full 0°C to 70°C industrial temperature range and applies to both standard and first-word fall-through timing modes.

How does the first-word fall-through (FWFT) mode function in the SN74V245-10PAG?

In FWFT mode, the first word written to an empty SN74V245-10PAG appears on the Q0–Q17 outputs after three valid low-to-high transitions of RCLK - no REN assertion is required. Subsequent words still require REN activation. This mode reduces control overhead in burst-oriented applications like packet streaming or audio frame transfer, and is selected at reset via FL, RXI, and WXI pin states.

Can the SN74V245-10PAG interface directly with 5-V logic systems?

Yes, the SN74V245-10PAG features 5-V tolerant inputs while operating from a 3.3-V V_CC supply. All control inputs (WEN, REN, LD, RS, OE, FL, RXI, WXI) and data inputs (D0–D17) accept 0–5.5-V signals without damage or level-shifting circuitry. This allows seamless integration with legacy 5-V microcontrollers, FPGAs, or bus interfaces alongside modern 3.3-V DSPs.

What are the default programmable flag offsets for the SN74V245-10PAG?

The SN74V245-10PAG defaults to 127-word offsets for both programmable almost-empty (PAE) and almost-full (PAF) flags - meaning PAE asserts when ≤127 words remain, and PAF asserts when ≥(4096 − 127) = 3969 words are stored. These values are stored in internal 12-bit offset registers and can be reloaded via the LD/WEN sequence on D0–D11.

How is depth expansion implemented using multiple SN74V245-10PAG devices?

Depth expansion uses daisy-chained configuration: FL is grounded on the first device and pulled high on subsequent devices; RXI connects to RXO of the prior device, and WXI connects to WXO of the prior device. The last device's RXO/WXO signals terminate unused. This configuration maintains synchronized flag propagation and enables seamless 8192×18 or larger FIFO arrays without external arbitration logic.