Infineon Technologies CY7C136A-55NXIT

Overview

CY7C136A-55NXIT from Cypress Semiconductor is a 2K × 8 true dual-port static RAM with independent left/right ports, 55 ns maximum access time, 110 mA max operating current, and 5 V ±10% supply. It functions as a master dual-port SRAM in shared-memory systems requiring simultaneous read/write access-e.g., multiprocessor inter-processor communication buffers or DSP cache coherency modules.

For engineers reviewing the CY7C136A-55NXIT datasheet, CY7C136A-55NXIT pinout, CY7C136A-55NXIT application, or CY7C136A-55NXIT equivalent, key selection criteria include BUSY arbitration logic, INT flag support for port-to-port signaling, asynchronous operation, automatic per-port power-down, and compatibility with CY7C142/CY7C146 slave devices for 16-bit+ data bus expansion.

Technical Context

This device implements fully asynchronous dual-port architecture with separate CE, R/W, and OE controls per port, enabling concurrent access to any memory location without internal arbitration delay. The BUSY output (open-drain, pull-up required) signals contention when both ports attempt access to the same address, while the INT flag (available on 52-pin PLCC/PQFP) indicates data placement at dedicated interrupt addresses (7FF_L, 7FE_R).

It supports two standby modes: ISB1 (both ports disabled, 35 mA max), ISB2 (one port active, 75 mA max), and ultra-low ISB3 (CMOS-input standby, 15 mA max). Memory array uses 0.65 µm CMOS process, delivering deterministic timing across commercial (0°C to +70°C) and industrial (–40°C to +85°C) temperature ranges.

Key Specifications

Pinout & Package

52-pin Plastic Quad Flat Package (PQFP), RoHS-compliant, with exposed thermal pad (connected to GND). Pin 1 marked by dot; top-view orientation aligns with JEDEC MS-026 standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C136-55NXI, CY7C136A-55NXIT offers identical performance but guarantees Pb-free packaging; versus CY7C142-55NXI, it provides full master functionality including BUSY arbitration and INT signaling-making it self-contained for standalone dual-processor designs.

Availability

CY7C136A-55NXIT is available at Aetrix Electronics and suitable for real-time multiprocessor systems, DSP cache buffers, industrial communication gateways, and bit-slice processor interconnects requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for CY7C136A-55NXIT 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 embedded and industrial applications, with focus on reliability and timing-critical system integration.

CY7C136A belongs to Cypress's legacy dual-port SRAM product line, engineered specifically for deterministic, contention-free memory sharing in multiprocessor, DSP, and bit-slice architectures-prioritizing low-latency arbitration and per-port power control.

FAQ

What is the function of the BUSY pin on CY7C136A-55NXIT?

The BUSY pin is an open-drain output that goes LOW when either port attempts to access the same memory address simultaneously. It requires an external pull-up resistor (typically 4.7 kΩ) and serves as a hardware arbitration signal-allowing external logic or firmware to pause one port until contention clears. Timing from address match to BUSY LOW is guaranteed ≤30 ns.

Can CY7C136A-55NXIT operate with a 3.3 V supply?

No. CY7C136A-55NXIT is specified only for 5 V ±10% (4.5–5.5 V) operation. Its input thresholds (VIH = 2.2 V, VIL = 0.8 V) and output drive levels (VOH ≥ 2.4 V, VOL ≤ 0.4 V) are designed for 5 V TTL/CMOS compatibility. Using 3.3 V violates absolute maximum ratings and will result in undefined behavior or permanent damage.

How does the INT flag work, and which packages support it?

INTL and INTR are open-drain interrupt flags asserting LOW when data is written to dedicated addresses 7FF_H (left port) or 7FE_H (right port). They are supported only on 52-pin PLCC and PQFP packages (not smaller footprints). Each flag operates independently and requires its own pull-up resistor; timing from write to INT assertion is ≤45 ns at –40°C to +85°C.

Is CY7C136A-55NXIT pin-compatible with CY7C136-55NXI?

Yes-CY7C136A-55NXIT is pin-, package-, and functionally identical to CY7C136-55NXI per datasheet Note 1. The "A" suffix denotes Pb-free packaging; all electrical characteristics, timing parameters, and pin functions match exactly. No PCB redesign or firmware changes are needed for substitution.