Infineon Technologies CY7C109B-15VC

Overview

CY7C109B-15VC from Cypress Semiconductor is a 128K × 8 (1,048,576-bit) high-speed CMOS static RAM with 15 ns maximum access time, TTL-compatible I/O, and dual chip enable (CE1 active LOW, CE2 active HIGH) for flexible memory expansion. It operates at 5V ±10%, supports automatic power-down when deselected, and retains data down to 2.0V. Used in embedded controllers, industrial PLCs, and legacy telecom interface buffers requiring deterministic read/write timing.

For engineers reviewing the CY7C109B-15VC datasheet, CY7C109B-15VC pinout, CY7C109B-15VC application, or CY7C109B-15VC equivalent, key selection criteria include tAA = 15 ns access time, ISB2 = 10 mA CMOS standby current, tri-state I/O control via OE/CE/WE, and SOJ-32 (400-mil) or TSOP-I-32 package compatibility with legacy PCB footprints.

Technical Context

This SRAM implements a full asynchronous interface with independent address latching, no internal clocks or refresh circuitry, and true bi-directional I/O pins (I/O0–I/O7) that enter high-impedance state during deselect, write, or OE disable. Its dual CE architecture allows seamless bank switching in 16-bit or 32-bit data bus systems without external logic.

The device uses standard CMOS process technology with TTL-level input thresholds (VIH = 2.2 V, VIL = 0.8 V), guarantees data retention at VCC = 2.0 V with ISB1 ≤ 40 mA and ISB2 ≤ 10 mA, and meets MIL-STD-883 Class 1A ESD rating (>2001 V).

Key Specifications

Pinout & Package

Package: 32-pin SOJ (400-mil width), JEDEC MS-012AC compliant. Body dimensions: 13.72 mm × 7.62 mm × 2.54 mm. Lead pitch: 1.27 mm. RoHS-compliant lead finish (SnPb or Pb-free per suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar static RAM applications.

Compared with IS61LV1024-15K and AS6C1008-15PCN, CY7C109B-15VC uniquely supports legacy 5V-only systems with dual CE expansion and SOJ-32 drop-in replacement capability, while delivering balanced speed (15 ns), power (10 mA ISB2), and industrial temperature range support.

Availability

CY7C109B-15VC is available at Aetrix Electronics and suitable for industrial PLCs, telecom line cards, network routers, and medical imaging systems requiring stable component supply with long lifecycle visibility.

Supply support for CY7C109B-15VC 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, PSoC, USB, and clock solutions for industrial, automotive, and consumer applications.

CY7C109B belongs to Cypress's legacy parallel SRAM product line, designed specifically for 5V embedded systems needing deterministic, non-refreshing memory with minimal board-level support circuitry.

FAQ

What is the minimum VCC required to retain data in CY7C109B-15VC?

Data retention is guaranteed at VCC = 2.0 V under conditions where CE1 > VCC – 0.3 V or CE2 < 0.3 V, and all inputs are within valid logic levels. At this voltage, ICCDR remains ≤ 150 µA, and tCDR = 0 ns - meaning retention begins immediately upon entering power-down mode. No external capacitor or backup source is required.

Can CY7C109B-15VC be used with a 3.3 V microcontroller?

No - CY7C109B-15VC is a 5V-only device. Its VIH minimum is 2.2 V, but VCC must be 5.0 V ±10%. Driving its inputs from a 3.3 V MCU violates the absolute maximum rating of VCC + 0.5 V on inputs and risks latch-up or parametric failure. A level-shifting buffer (e.g., 74LVC4245) is mandatory for interoperability.

What is the function of Pin 15 (NC) on the SOJ-32 package?

Pin 15 is a no-connect terminal - it is not bonded to the die and serves only as mechanical support. Cypress documentation explicitly states NC pins "are not connected on the die." It may be left floating, tied to GND for mechanical stability, or omitted from PCB routing; no electrical function or timing impact is associated with this pin.

How does the dual CE architecture improve memory expansion?

CE1 (active LOW) and CE2 (active HIGH) allow hierarchical decoding: A16 can drive CE2 directly while lower address bits feed CE1 logic, enabling 256 KB systems using two CY7C109B-15VC devices without external GALs or CPLDs. This eliminates address decode delay and reduces propagation skew versus single-CE alternatives.