Infineon Technologies CY7C1021B-15ZXI

Overview

CY7C1021B-15ZXI from Cypress Semiconductor is a 1-Mbit (64K × 16) high-speed CMOS static RAM with 15 ns maximum access time, 5 V ±10% supply, industrial temperature range (–40°C to +85°C), and Pb-free 44-pin TSOP II packaging. It supports independent byte-wide write control via BHE/ BLE, automatic CE-based power-down (ISB2 = 10 mA), and operates in read/write modes with TTL/CMOS-compatible inputs.

For engineers reviewing the CY7C1021B-15ZXI datasheet, CY7C1021B-15ZXI pinout, CY7C1021B-15ZXI application, or CY7C1021B-15ZXI equivalent, key selection considerations include tAA = 15 ns timing compliance, dual-byte enable architecture for partial-word writes, industrial-grade thermal resistance (ΘJA = 76.89°C/W), and compatibility with legacy 5 V memory bus systems requiring low standby current and deterministic tri-state behavior.

Technical Context

The CY7C1021B-15ZXI implements a synchronous, address-decoded SRAM array with row/column decoding across 512 × 2048 cells. Its read path uses sense amplifiers with tDOE = 7 ns and tHZOE = 7 ns (5 pF load), while write operations require overlapping CE LOW, WE LOW, and active BHE/BLE to latch data on I/O9–I/O16 or I/O1–I/O8 respectively.

Power management relies on CE-driven automatic power-down: ISB2 = 10 mA at CMOS input conditions (VIN > VCC – 0.3 V or < 0.3 V), with full ICC = 130 mA during active operation at fMAX = 1/tRC. Input/output pins enter high-impedance state under four conditions: CE HIGH, OE HIGH, BHE/BLE HIGH, or during write cycles.

Key Specifications

Pinout & Package

Package: 44-pin TSOP Type II (0.400-inch width), Pb-free, JEDEC MO-143AC compliant. Body dimensions: 11.20–11.30 mm × 10.16–10.26 mm × 1.0 mm max height.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed parallel SRAM applications.

Compared with IS61LV1024-15K, CY7C1021B-15ZXI offers Pb-free TSOP II packaging and lower ISB2 (10 mA vs. 12 mA), making it preferable for industrial surface-mount production; versus MC68HC11F1M15, it provides true external parallel SRAM functionality with deterministic timing and byte-select control absent in microcontroller-integrated RAM.

Availability

CY7C1021B-15ZXI is available at Aetrix Electronics and suitable for industrial PLCs, legacy 16-bit microprocessor systems, and automotive instrument clusters requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant manufacturing.

Supply support for CY7C1021B-15ZXI 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 founded in 1982, specializing in memory, microcontrollers, and programmable system-on-chip solutions.

The CY7C1021B belongs to Cypress's parallel SRAM product line, designed specifically for high-reliability, low-latency memory expansion in industrial, automotive, and communications equipment requiring deterministic timing and industrial temperature operation.

FAQ

Is CY7C1021B-15ZXI compatible with 3.3 V systems?

No. The CY7C1021B-15ZXI is specified exclusively for 5 V ±10% operation (4.5 V to 5.5 V). Its VIH minimum is 2.2 V and VIL maximum is 0.8 V, but internal circuitry, timing parameters, and power consumption are characterized only at 5 V. Interfacing with 3.3 V logic requires level-shifting circuitry and invalidates guaranteed tAA = 15 ns performance.

What is the meaning of "ZXI" in the part number CY7C1021B-15ZXI?

"Z" denotes TSOP II package, "X" indicates Pb-free construction, and "I" specifies industrial temperature range (–40°C to +85°C). This suffix uniquely identifies the device as a RoHS-compliant, industrial-grade 44-pin TSOP II variant with 15 ns access speed - distinct from commercial (C), automotive (E), or Pb-containing (no X) versions.

Does CY7C1021B-15ZXI support asynchronous burst reads?

No. The CY7C1021B-15ZXI is a static RAM with purely asynchronous operation: each read or write requires explicit CE, OE (for reads), WE (for writes), and BHE/BLE assertion per cycle. It lacks burst address generation, clock input, or sequential access modes - all timing is referenced to address and control signal edges per the truth table and switching waveforms.

Can BLE and BHE be asserted simultaneously for full 16-bit writes?

Yes. When both BLE and BHE are LOW while CE and WE are LOW, the device performs a full 16-bit write: data on I/O1–I/O8 is written to the lower byte and data on I/O9–I/O16 is written to the upper byte of the addressed location. This is explicitly defined in the truth table and functional description as "Write – All bits" mode.