Infineon Technologies CY7C1325G-133AXC

Overview

CY7C1325G-133AXC from Cypress Semiconductor is a 4-Mbit (256K × 18) flow-through synchronous SRAM with 133 MHz clock support, 6.5 ns clock-to-output delay, 3.3 V core supply (VDD), and dual-voltage I/O (2.5 V/3.3 V VDDQ), designed for high-speed secondary cache interfacing in Pentium-class microprocessor systems.

For engineers reviewing the CY7C1325G-133AXC datasheet, CY7C1325G-133AXC pinout, CY7C1325G-133AXC application, or CY7C1325G-133AXC equivalent, key selection criteria include burst mode configurability (linear vs. interleaved), synchronous self-timed write capability, separate ADSP/ADSC address strobes, and ZZ sleep mode with data retention - all critical for cache coherency and power-aware embedded computing designs.

Technical Context

The device implements a 2-bit on-chip wraparound burst counter fed by A[1:0], enabling automatic address increment during burst reads/writes. Burst order (interleaved or linear) is statically selected via the MODE pin, with internal pull-up ensuring default interleaved operation when unconnected.

All synchronous inputs - including addresses, CE1/CE2/CE3, ADSP/ADSC, ADV, GW, BWE, BW[A:B], and CLK - are registered on the positive clock edge. Asynchronous controls OE and ZZ operate independently of CLK, with ZZ requiring external grounding per errata (Pin 64) to avoid unintended sleep activation.

Key Specifications

Pinout & Package

Package: 100-pin TQFP (14 × 20 × 1.4 mm), Pb-free, JEDEC-standard JESD8-5 compatible.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS61LV25618AL-133TQLI and MT48LC16M18A2-75:G, CY7C1325G-133AXC uniquely delivers VDDQ voltage flexibility, hardware-configurable burst order, and ZZ sleep - making it the only option for legacy Pentium cache designs requiring deterministic timing and power-aware operation.

Availability

CY7C1325G-133AXC is available at Aetrix Electronics and suitable for Intel Pentium-based industrial PCs, real-time PLC controllers, legacy test equipment, and avionics data buffering modules requiring stable component supply and long-term obsolescence management.

Supply support for CY7C1325G-133AXC 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

Cypress Semiconductor (now part of Infineon Technologies) is a fabless semiconductor company specializing in memory, microcontrollers, and programmable solutions for industrial, automotive, and communications markets.

CY7C1325G belongs to Cypress's legacy synchronous SRAM product line, engineered specifically for high-performance cache subsystems in x86-compatible processors and deterministic real-time control systems.

FAQ

What is the correct handling of the ZZ pin per official errata?

The ZZ pin (Pin 64) must be externally connected to ground, as stated in the datasheet errata on page 21. Leaving it floating risks unintended entry into sleep mode due to noise or leakage, even though the pin has an internal pull-down. Grounding ensures stable normal operation and prevents data access interruption during critical cache reads.

Can CY7C1325G-133AXC operate with 2.5 V I/O while using 3.3 V core supply?

Yes - VDD is fixed at 3.3 V for core logic, while VDDQ is independently configurable for either 2.5 V or 3.3 V. This allows direct interfacing with 2.5 V FPGAs or ASICs without level shifters, provided VDDQ decoupling and signal integrity meet JEDEC JESD8-5 requirements for mixed-voltage operation.

How does the burst counter behave during interleaved vs. linear mode?

In interleaved mode (MODE = HIGH), the 2-bit counter sequences as 0→2→1→3; in linear mode (MODE = LOW), it sequences as 0→1→2→3. Both use wraparound behavior. The counter advances on each ADV assertion during burst cycles, and initial address A[1:0] is latched at ADSP/ADSC activation - matching Pentium and i486 burst protocols respectively.

Is CY7C1325G-133AXC suitable for new designs given its legacy status?

Yes - Aetrix Electronics maintains active inventory and long-term sourcing agreements for CY7C1325G-133AXC. Its pinout, timing, and electrical specs remain unchanged; design documentation, IBIS models, and application notes are fully archived and accessible. It is recommended for repair, replacement, and continuity builds of certified legacy systems.