Infineon Technologies CY7C136-55JXC

Overview

CY7C136-55JXC from Cypress Semiconductor is a 2K × 8 true dual-port static RAM with independent left/right ports, 55 ns maximum access time, 5 V ±10% supply, and 52-pin PLCC package. It enables simultaneous read access to the same memory location and supports master-slave expansion for 16-bit+ data buses in multiprocessor cache systems.

For engineers reviewing the CY7C136-55JXC datasheet, CY7C136-55JXC pinout, CY7C136-55JXC application, or CY7C136-55JXC equivalent, key selection criteria include BUSY arbitration logic, INT flag support for port-to-port communication, automatic per-port power-down, and compatibility with CY7C146 slave devices in shared-memory architectures.

Technical Context

This device implements fully asynchronous dual-port SRAM architecture with separate address, data, and control lines for left (L) and right (R) ports. Each port features independent CE, R/W, and OE pins, enabling concurrent read/write operations subject to BUSY arbitration when accessing identical addresses.

The 52-pin PLCC version includes open-drain BUSY outputs (requiring external pull-ups) and bidirectional INT flags tied to fixed internal locations (7FF_L, 7FE_R). Power management is implemented via TTL- or CMOS-level CE-driven automatic power-down, with standby current as low as 35 mA (both ports disabled, industrial temp).

Key Specifications

Pinout & Package

Package: 52-pin Plastic Leaded Chip Carrier (PLCC), JEDEC standard, surface-mount, lead-free compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-port SRAM applications.

Compared with CY7C136A-55JXC, this part offers identical functionality but may differ in wafer lot traceability; versus CY7C146-55JXC, it provides full master capability including BUSY arbitration and interrupt generation-essential for autonomous dual-processor systems.

Availability

CY7C136-55JXC is available at Aetrix Electronics and suitable for DSP cache memory, multiprocessor shared buffers, bit-slice processor interconnects, and legacy system memory expansion requiring stable component supply and long-term industrial lifecycle support.

Supply support for CY7C136-55JXC 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-reliability memory and programmable solutions for industrial, automotive, and communications infrastructure.

CY7C136 belongs to Cypress's legacy dual-port SRAM product line, engineered specifically for deterministic, low-latency shared-memory applications in real-time embedded systems and legacy equipment upgrades.

FAQ

Is CY7C136-55JXC pin-compatible with CY7C136-45JXC?

Yes - both use identical 52-pin PLCC packaging and share the same pinout. The only difference is access time: 55 ns vs. 45 ns. Electrical characteristics (VCC, VIH/VIL, drive strength) and timing parameters outside access time are identical, allowing direct substitution in designs where 55 ns timing meets system requirements.

Does CY7C136-55JXC support 3.3 V operation?

No - it is specified only for 5 V ±10% (4.5–5.5 V) operation. The absolute maximum ratings prohibit applying voltages below 4.5 V or above 5.5 V. Using it with 3.3 V logic interfaces requires level-shifting circuitry on all address, data, and control lines to avoid undefined behavior or damage.

What is the purpose of the BUSY pin, and how must it be connected?

BUSY is an open-drain output that goes LOW when its port attempts to access an address currently being accessed by the other port. It requires an external pull-up resistor (typically 4.7 kΩ to VCC) to generate a valid HIGH level. Without the pull-up, BUSY remains floating and cannot signal arbitration status reliably.

Can CY7C136-55JXC operate without using the INT pins?

Yes - INTL and INTR are optional features. They can be left unconnected (with appropriate PCB keep-out) if inter-processor interrupt signaling is handled via software polling or alternate hardware. All core dual-port memory functions remain fully operational without INT usage.