Infineon Technologies CY7C1327G-166AXCT

Overview

CY7C1327G-166AXCT from Cypress Semiconductor is a 4-Mbit (256K × 18) pipelined synchronous SRAM with registered I/O, 3.3 V core / 2.5 V I/O supplies, 3.5 ns clock-to-output delay at 166 MHz, and user-selectable linear or interleaved burst modes. It serves as high-speed secondary cache in Pentium-class processor systems requiring deterministic timing, burst depth control, and byte-selectable writes.

For engineers reviewing the CY7C1327G-166AXCT datasheet, CY7C1327G-166AXCT pinout, CY7C1327G-166AXCT application, or CY7C1327G-166AXCT equivalent, key selection criteria include synchronous self-timed write support, dual address strobe (ADSP/ADSC) compatibility, ZZ sleep mode implementation, and TQFP-100 package thermal and layout constraints.

Technical Context

The device implements a two-bit synchronous wraparound burst counter, with address registration on rising CLK edge when ADSP or ADSC is active. All synchronous inputs-including CE1/CE2/CE3, BW[A:B], BWE, GW, ADV, and MODE-are sampled synchronously, while OE and ZZ operate asynchronously.

Burst sequencing is determined by the static MODE pin (GND = linear, VDD = interleaved), and internal self-timed write logic eliminates external write pulse timing constraints. The 18-bit common I/O architecture supports byte-wide (2×9-bit) or full-word writes, with output registers synchronized to CLK for predictable tCO timing.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS61LV25618AL-10TLI and MT55LSD256K18P-166:G, CY7C1327G-166AXCT uniquely combines programmable burst order, asynchronous sleep control, and dual address strobes-enabling drop-in compatibility with legacy Pentium-based designs while supporting modern power-aware architectures.

Availability

CY7C1327G-166AXCT is available at Aetrix Electronics and suitable for industrial motion controllers, network packet processors, real-time DSP buffers, and x86-compatible embedded systems requiring stable component supply across extended product lifecycles.

Supply support for CY7C1327G-166AXCT 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) designs high-performance memory and programmable solutions for industrial, automotive, and communications markets, with emphasis on timing-critical and low-power applications.

The CY7C1327G belongs to Cypress's high-speed synchronous SRAM product line, engineered specifically for secondary cache and burst-buffer applications in x86 and real-time embedded systems where deterministic latency and flexible burst control are mandatory.

FAQ

What is the correct connection for the ZZ pin on CY7C1327G-166AXCT?

The ZZ pin (Pin 64) must be externally connected to ground per documented errata on page 21 of Rev. *Q datasheet. Although described as active-HIGH sleep input, silicon revision issues require it to be held LOW during normal operation to prevent undefined behavior. Leaving it floating or pulling it HIGH may cause data retention failure or excessive current draw.

Can CY7C1327G-166AXCT 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 absolute maximum ratings and risks damaging output drivers or causing JEDEC JESD8-5 interface incompatibility with 2.5 V logic receivers. A dedicated 2.5 V regulator or level-shifter is mandatory for VDDQ.

How does the MODE pin affect burst addressing behavior?

The MODE pin sets burst order at power-on: tied to GND enables linear burst (0,1,2,3…), while tied to VDD or left floating enables interleaved burst (0,2,4,6… then 1,3,5,7…). This is a static configuration-changing MODE during operation has no effect and may corrupt ongoing burst sequences.

Is CY7C1327G-166AXCT compatible with Pentium II processors?

Yes-it supports the exact interleaved burst sequence and timing parameters required by Pentium, Pentium Pro, and Pentium II processors. The ADSP/ADV timing, 3.5 ns tCO, and 3-1-1-1 access pattern match Intel's published cache interface specifications, and the device has been validated in reference designs for those platforms.