Texas Instruments SN74V225-7PAG

Overview

SN74V225-7PAG from Texas Instruments is a 1024 × 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. Used in TMS320 DSP glueless interfaces, network and video data pipelines.

For engineers reviewing the SN74V225-7PAG datasheet, SN74V225-7PAG pinout, SN74V225-7PAG application, or SN74V225-7PAG equivalent, key selection factors include its 1024-word depth, dual-register-buffered EF/OR and FF/IR flags, programmable almost-empty/almost-full offsets, half-full flag capability, and 64-pin TQFP package compatibility with TI's DSP-Sync™ architecture.

Technical Context

This FIFO employs synchronous dual-port architecture with independent, asynchronous or coincident RCLK and WCLK inputs-each gated by REN and WEN enables. All data transfers are synchronized to low-to-high clock edges, and internal pointers operate independently for read and write operations.

It implements configurable timing behavior via FL/RXI/WXI pin states at reset, enabling either FWFT mode (first word appears on outputs after three RCLK transitions without REN) or standard mode (explicit REN + RCLK required). Flag logic-including EF/OR, FF/IR, PAE, PAF, and HF-is fully synchronous and updated on respective clock edges.

Key Specifications

Pinout & Package

Packaged in a 64-pin thin quad flat package (TQFP), SN74V225-7PAG features 18-bit bidirectional data paths, dual independent clocks (RCLK/WCLK), and dedicated expansion/control pins for flexible system integration.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V2115L10PF and ICS650G-01LFT, SN74V225-7PAG uniquely combines 5-V input tolerance, FWFT timing, half-full flag, and native daisy-chain expansion - making it optimal for TI DSP ecosystems requiring robust, low-latency, field-upgradeable buffering.

Availability

SN74V225-7PAG is available at Aetrix Electronics and suitable for DSP interface design, real-time signal processing, and industrial communications equipment requiring stable component supply and long-term lifecycle support.

Supply support for SN74V225-7PAG 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 decades of leadership in high-performance timing and interface solutions.

SN74V225-7PAG belongs to the DSP-Sync™ family of synchronous FIFOs, engineered specifically to provide glueless, low-latency buffering between TMS320 DSPs and peripheral subsystems - emphasizing timing predictability, voltage flexibility, and system-level expandability.

FAQ

What is the memory organization of the SN74V225-7PAG?

The SN74V225-7PAG implements a 1024 × 18-bit synchronous FIFO memory array. This means it stores 1024 words, each 18 bits wide, supporting parallel data throughput for high-bandwidth applications such as DSP-to-ADC buffering and video pipeline alignment. The SN74V225-7PAG uses high-performance submicron CMOS technology to achieve fast access and reliable operation across its specified temperature range.

Does the SN74V225-7PAG support both standard and first-word fall-through (FWFT) timing modes?

Yes, the SN74V225-7PAG supports both timing modes. Mode selection is determined at reset via the FL, RXI, and WXI pin states. In FWFT mode, the first written word appears on the Q-bus after three RCLK transitions without requiring REN assertion - reducing read latency. In standard mode, explicit REN activation is mandatory for every read, including the first word. The SN74V225-7PAG's dual-mode capability makes it adaptable to diverse system timing constraints.

What are the default programmable flag offsets for the SN74V225-7PAG?

The SN74V225-7PAG 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 ≥900 words are stored (1024 − 127 = 897, rounded per flag logic). These offsets are user-loadable via D0–D11 and the LD/WEN sequence. The SN74V225-7PAG retains these defaults after power-on reset unless explicitly reprogrammed.

How does the half-full flag (HF) function on the SN74V225-7PAG?

On the SN74V225-7PAG, the half-full flag (HF) is an asynchronous output that goes low when more than 512 words are stored - indicating the FIFO is over half capacity. HF remains asserted until the difference between write and read pointers drops to ≤512, then resets high on the next RCLK edge. In daisy-chain configurations, the same pin serves as WXO to signal completion of a write to the last location. The SN74V225-7PAG uses HF to simplify balanced buffer management without software polling.

Can the SN74V225-7PAG be used in systems with mixed 3.3-V and 5-V logic?

Yes, the SN74V225-7PAG operates from a 3.3-V V_CC supply while supporting 5-V tolerant inputs on all control and data pins (D0–D17, REN, WEN, etc.). This eliminates the need for external level shifters when interfacing with 5-V microcontrollers, FPGAs, or legacy peripherals - simplifying design, reducing component count, and improving signal integrity. The SN74V225-7PAG maintains full timing and functional specification under this mixed-voltage operation.