Infineon Technologies CY7C1327G-133AXI

Overview

CY7C1327G-133AXI from Cypress Semiconductor is a 4-Mbit (256K × 18) pipelined synchronous SRAM with registered I/O, 133 MHz clock operation, 4.0 ns clock-to-output delay, dual power rails (3.3 V core / 2.5 V I/O), and user-selectable linear or interleaved burst mode - deployed in high-speed secondary cache subsystems for Pentium-class processors.

For engineers reviewing the CY7C1327G-133AXI datasheet, CY7C1327G-133AXI pinout, CY7C1327G-133AXI application, or CY7C1327G-133AXI equivalent, key selection criteria include synchronous burst timing compliance, byte-write control granularity, ZZ sleep mode implementation, and TQFP-100 package compatibility with legacy x86 memory controller interfaces.

Technical Context

The device implements a two-bit synchronous wraparound burst counter, clocked on the rising edge of CLK, with address capture triggered by either ADSP (processor strobe) or ADSC (controller strobe). All synchronous inputs - including A[1:0], CE1/CE2/CE3, BW[A:B], BWE, GW, ADV, ADSP, ADSC - are registered on the same clock edge.

It supports asynchronous OE for output tristating and asynchronous ZZ (active-HIGH) sleep mode with internal pull-down; however, per errata, Pin 64 (ZZ) must be externally tied to ground. Data I/O uses common bidirectional DQA/DQB/DQPA/DQPB lines with output registers synchronized to CLK.

Key Specifications

Pinout & Package

Package: 100-pin Thin Quad Flat Package (TQFP), RoHS-compliant, body size 14 mm × 14 mm, 0.5 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1327G-166AXI, the -133AXI trades 33 MHz bandwidth for relaxed timing margins and lower operating current (225 mA vs. 240 mA); versus IS61LV25618AL-10TLI, it adds pipelined burst capability and processor-coherent strobe logic at the cost of interface complexity and power.

Availability

CY7C1327G-133AXI is available at Aetrix Electronics and suitable for industrial motion controllers, legacy telecom baseband upgrades, Pentium-class CPU cache modules, and network packet buffering systems requiring stable component supply across extended production lifecycles.

Supply support for CY7C1327G-133AXI 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 embedded and industrial applications.

The CY7C1327G belongs to Cypress's high-speed synchronous SRAM product line, designed specifically for burst-mode secondary cache and real-time buffer applications in x86-compatible and custom controller-based systems.

FAQ

What is the correct configuration for the ZZ pin on CY7C1327G-133AXI?

The ZZ pin (Pin 64) must be externally connected to ground per documented errata - despite its active-HIGH specification, leaving it floating or pulling it HIGH causes undefined sleep behavior. The internal pull-down is insufficient; a direct 0 Ω connection to VSS is required for reliable operation and to avoid inadvertent entry into sleep mode during normal operation.

How does burst addressing work when MODE is set to linear versus interleaved?

In linear mode (MODE = GND), burst addresses increment sequentially: A, A+1, A+2, A+3. In interleaved mode (MODE = VDD/floating), addresses follow Intel Pentium order: A, A+2, A+1, A+3 - optimized for 32-bit bus utilization with 16-bit words. The 2-bit internal counter generates both sequences automatically upon ADV assertion during a burst cycle.

Can CY7C1327G-133AXI operate with only 3.3 V applied to both VDD and VDDQ?

No - the device requires separate 3.3 V on VDD (core) and 2.5 V on VDDQ (I/O). Applying 3.3 V to VDDQ violates the absolute maximum rating (VDDQ ≤ 2.7 V) and risks damage to output drivers and JEDEC JESD8-5 interface compliance. A dedicated 2.5 V regulator or level-shifting circuit is mandatory for VDDQ.

What is the difference between ADSP-initiated and ADSC-initiated write cycles?

ADSP-initiated writes require two clock cycles: address latched on first CLK rise, data written on second CLK rise if GW/BWE active. ADSC-initiated writes complete in one clock cycle - address and data captured and written simultaneously. ADSP is prioritized when both strobes are active, and ADSP is ignored if CE1 is deasserted.