Infineon Technologies CY7C1381D-100AXCT

Overview

CY7C1381D-100AXCT from Cypress Semiconductor is a 18-Mbit (512K × 36) synchronous flow-through SRAM with 133 MHz bus operation, 6.5 ns clock-to-output delay, 3.3 V core supply (VDD), 2.5/3.3 V I/O supply (VDDQ), and JEDEC-standard Pb-free 100-pin TQFP packaging. It serves as high-speed cache or buffer memory in Pentium-class processor systems requiring burst-mode interfacing with minimal glue logic.

For engineers reviewing the CY7C1381D-100AXCT datasheet, CY7C1381D-100AXCT pinout, CY7C1381D-100AXCT application, or CY7C1381D-100AXCT equivalent, key selection criteria include burst sequence mode (interleaved/linear), ZZ sleep control behavior, VDDQ voltage tolerance, CE1/CE2/CE3 enable timing, and JTAG boundary-scan limitations per errata.

Technical Context

The CY7C1381D-100AXCT implements a synchronous, clock-driven architecture where all address, data, and control inputs (except OE and ZZ) are registered on the rising edge of CLK. A 2-bit on-chip burst counter captures A[1:0] at ADSP/ADSC assertion and auto-increments for subsequent burst cycles controlled by ADV.

It supports dual-burst initiation via processor (ADSP) or controller (ADSC) strobes, with asynchronous OE enabling tristate output control and asynchronous ZZ enabling non-time-critical sleep. The device uses separate byte write enables (BWA–BWD) qualified by BWE and global write (GW), and features IEEE 1149.1 JTAG boundary scan-though errata require BYPASS mode during testing.

Key Specifications

Pinout & Package

Package: 100-pin TQFP (14 × 20 × 1.4 mm), JEDEC-standard Pb-free, with exposed thermal pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C33128A-10BIN and IS61WV102432BLL-10MLI, CY7C1381D-100AXCT uniquely provides configurable burst mode, asynchronous sleep control, and IEEE 1149.1 boundary scan-critical for Pentium-compatible designs requiring debug visibility and power-aware operation.

Availability

CY7C1381D-100AXCT is available at Aetrix Electronics and suitable for high-speed CPU cache subsystems, network packet buffering, and industrial motion control systems requiring stable component supply, long-lifecycle support, and Pb-free compliance.

Supply support for CY7C1381D-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 programmable system-on-chip (PSoC), memory, and USB solutions for industrial, automotive, and consumer applications.

CY7C1381D belongs to Cypress's high-speed synchronous SRAM product line, designed specifically for cache and buffer applications in microprocessor-based systems requiring burst-mode compatibility and low-latency deterministic access.

FAQ

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

The ZZ pin (Pin 64 in TQFP) must be externally connected to ground for reliable operation. Although internally pulled down, Cypress errata (Document 38-05544 Rev. *V, page 32) explicitly requires this external connection to prevent unintended sleep entry. Leaving ZZ floating or driving it HIGH may cause intermittent data retention failure during active operation.

Can CY7C1381D-100AXCT operate with 2.5 V VDDQ while using 3.3 V VDD?

Yes - the device is specified to operate with 3.3 V core (VDD) and independently supplied 2.5 V or 3.3 V I/O (VDDQ). This dual-supply capability allows direct interfacing with 2.5 V logic families while maintaining full 133 MHz performance and 6.5 ns t_CO, as confirmed in the DC and AC electrical characteristics tables (pages 20–23).

Is JTAG boundary scan functional on CY7C1381D-100AXCT?

JTAG is physically implemented per IEEE 1149.1, but Cypress errata mandates use only in BYPASS mode. Functional testing in EXTEST or SAMPLE/PRELOAD modes is not guaranteed due to silicon-level issues. For production test, rely on functional verification via ADSP/ADSC timing rather than JTAG scan chains.

How does burst addressing work when both ADSP and ADSC are asserted simultaneously?

ADSP has strict priority over ADSC: when both are active LOW, only ADSP is recognized and the address is captured from the processor bus. The ADSC signal is ignored in that cycle. This prioritization ensures deterministic arbitration in systems where CPU and cache controller share the same SRAM bus.