Infineon Technologies CY7C1345G-100AXCT

Overview

CY7C1345G-100AXCT from Cypress Semiconductor is a 4-Mbit (128K × 36) flow-through synchronous SRAM with 3.3 V core supply, 2.5/3.3 V I/O supply, and 8.0 ns clock-to-output delay at 100 MHz. It supports Intel Pentium–compatible interleaved or linear burst sequences via MODE pin selection, features synchronous self-timed write, asynchronous OE, and ZZ sleep mode, and is used in high-speed CPU cache subsystems requiring deterministic timing and low-latency burst access.

For engineers reviewing the CY7C1345G-100AXCT datasheet, CY7C1345G-100AXCT pinout, CY7C1345G-100AXCT application, or CY7C1345G-100AXCT equivalent, key selection criteria include burst sequence control (MODE), dual address strobes (ADSP/ADSC), byte-write granularity (BWA–BWD + BWE), synchronous clocked interface (CLK), and TQFP-100 package compatibility with JEDEC JESD8-5 I/O standards.

Technical Context

The CY7C1345G-100AXCT implements a synchronous flow-through architecture where all address, data, and control inputs (except OE and ZZ) are registered on the rising edge of CLK. Its 2-bit on-chip burst counter captures A[1:0] at ADSP/ADSC assertion and auto-increments for subsequent burst cycles, supporting both interleaved (Pentium-compatible) and linear sequences selected statically by the MODE pin.

Burst initiation is decoupled between processor (ADSP) and controller (ADSC) paths, with priority given to ADSP when both are active. Write operations use synchronous self-timed logic: global writes (GW) override byte-selects (BWA–BWD), while byte writes require simultaneous assertion of BWE and one BWx signal. Output enable (OE) operates asynchronously to tristate DQ/DQP pins independently of clock timing.

Key Specifications

Pinout & Package

Package: 100-pin TQFP (14 mm × 20 mm × 1.4 mm), Pb-free, JEDEC MO-145 compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS61LV51236L-100TQLI and AS7C3256A-10TCN, the CY7C1345G-100AXCT uniquely delivers configurable burst sequencing, dual-address-strobe arbitration, and guaranteed 8.0 ns tCO-making it the only option for legacy x86 cache subsystems requiring Pentium-level timing compliance and hardware-controlled sleep.

Availability

CY7C1345G-100AXCT is available at Aetrix Electronics and suitable for high-speed CPU cache interfaces, multi-controller memory hubs, configurable burst memory subsystems, and low-power embedded cache applications requiring stable component supply across extended production lifecycles.

Supply support for CY7C1345G-100AXCT 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 system-on-chip solutions for industrial, automotive, and communications markets.

The CY7C1345G belongs to Cypress's legacy synchronous SRAM product line, designed specifically for second-level CPU cache applications requiring deterministic burst timing, dual-master interface support, and JEDEC-compliant 3.3 V/2.5 V mixed-voltage operation.

FAQ

What is the function of the MODE pin, and how must it be configured?

The MODE pin selects burst address order: LOW enables linear burst, HIGH or floating enables interleaved (Pentium-compatible) burst. It is a static strap pin-must be set before device initialization and held stable during operation. Internal pull-up ensures default interleaved behavior if left unconnected, but external pull-down is required for linear mode.

Why does the datasheet require external grounding of the ZZ pin (Pin 64)?

Due to a documented silicon errata (Rev. *P, page 22), the ZZ pin exhibits unreliable sleep-mode entry unless externally tied to ground. Though the pin has an internal pull-down, noise sensitivity and threshold variation necessitate hard grounding to ensure deterministic ZZ sleep activation and data retention during low-power states.

How does the CY7C1345G-100AXCT handle simultaneous ADSP and ADSC assertion?

When both ADSP and ADSC are asserted LOW, the device recognizes only ADSP-the processor strobe takes strict priority. ADSC is ignored in this condition, ensuring cache coherency in systems where CPU and controller may momentarily overlap address strobes during state transitions or error recovery.

Can the CY7C1345G-100AXCT operate with 2.5 V I/O while maintaining 3.3 V core voltage?

Yes-VDDQ (pins 13, 22, 31, 40, 49, 58, 67, 76, 85, 94) accepts 2.5 V ± 0.2 V independently of VDD (3.3 V ± 0.3 V). This allows direct interfacing with 2.5 V processor buses while preserving full 3.3 V core performance, including 8.0 ns tCO and 205 mA max operating current.