Infineon Technologies CY7C1381D-133AXIT

Overview

CY7C1381D-133AXIT from Cypress Semiconductor is a 18-Mbit synchronous flow-through SRAM with 512K × 36 organization, designed for high-speed secondary cache in Pentium®-compatible systems. It operates at 133 MHz with 6.5 ns clock-to-output delay, 3.3V core supply (VDD), 2.5V/3.3V I/O supply (VDDQ), and supports Intel®-compatible interleaved or linear burst sequences via MODE pin selection.

For engineers reviewing the CY7C1381D-133AXIT datasheet, CY7C1381D-133AXIT pinout, CY7C1381D-133AXIT application, or CY7C1381D-133AXIT equivalent, key selection criteria include burst timing compatibility with ADSP/ADSC strobes, JEDEC-standard 100-pin TQFP packaging, synchronous self-timed write capability, and dual VDD/VDDQ supply separation for mixed-voltage system integration.

Technical Context

This SRAM implements a 2-bit on-chip wraparound burst counter that captures A[1:0] at ADSP/ADSC assertion and auto-increments addresses during burst reads/writes. All synchronous inputs - including address, CE1/CE2/CE3, BWx, BWE, GW, ADSP, ADSC, ADV, and CLK - are registered on the rising edge of CLK.

It features asynchronous OE and ZZ controls, with OE enabling tri-state output control independent of clock timing, and ZZ placing the device in low-power sleep while preserving data integrity. The device supports both processor-initiated (ADSP) and controller-initiated (ADSC) burst access, with ADV governing internal address advancement.

Key Specifications

Pinout & Package

Package: JEDEC-standard Pb-free 100-pin Thin Quad Flat Package (TQFP), 14 × 14 mm body, 0.5 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS61WV102436BLL-133TQLI and CY7C1399-133AXC, the CY7C1381D-133AXIT uniquely combines dual-supply I/O, full ADSP/ADSC/ADV burst control, and three chip enables - making it the only option for Pentium®-compatible, mixed-voltage, multi-bank cache subsystems.

Availability

CY7C1381D-133AXIT is available at Aetrix Electronics and suitable for secondary cache subsystems, high-speed network buffers, industrial motion controller memory, and real-time video frame buffering requiring stable component supply and long-term obsolescence management.

Supply support for CY7C1381D-133AXIT 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 U.S.-based semiconductor company specializing in high-performance memory, microcontrollers, and programmable analog/digital ICs for industrial, automotive, and communications markets.

The CY7C1381D belongs to Cypress's high-speed synchronous SRAM product line, engineered specifically for low-latency, burst-mode cache and buffer applications in x86-compatible and real-time embedded systems.

FAQ

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

The MODE pin selects burst sequence type: HIGH (or floating, due to internal pull-up) enables Intel® Pentium®-compatible interleaved addressing; LOW (tied to GND) selects linear burst. It is a static strap pin - configuration must be fixed before operation and cannot change dynamically during burst cycles. Incorrect or floating MODE in linear mode may cause misaligned cache fills.

Can CY7C1381D-133AXIT operate with only 2.5V applied to both VDD and VDDQ?

No. The device requires 3.3V ±0.3V on VDD for core logic operation; applying 2.5V to VDD will prevent functional operation and may damage the core circuitry. VDDQ may be 2.5V or 3.3V independently, but VDD must remain at 3.3V. This separation enables interfacing with 2.5V I/O buses while sustaining core performance.

How does the ZZ sleep mode affect timing and data retention?

When ZZ is driven HIGH, the device enters non-time-critical sleep: all outputs tri-state, internal clocks halt, and dynamic power drops sharply - but SRAM cell data is retained indefinitely as long as VDD remains within specification (3.0–3.6V). No minimum sleep duration or wake-up sequence is required; asserting ZZ LOW resumes full operation on the next CLK edge.

Why are CE2 and CE3 not present on the 119-ball BGA variants (CY7C1381F)?

The CY7C1381F (119-ball BGA) implements only CE1 for chip select, simplifying routing in space-constrained layouts. In contrast, the CY7C1381D (100-pin TQFP) retains CE2 (active HIGH) and CE3 (active LOW) to support three-level bank decoding in larger systems. This reflects package-specific feature pruning - not a functional downgrade - and is documented in the Cypress selection guide footnote [2].