Infineon Technologies CY7C1021BN-15ZXIT

Overview

CY7C1021BN-15ZXIT from Cypress Semiconductor is a 1-Mbit (64 K × 16) high-speed CMOS static RAM with 15 ns access time, industrial temperature range (–40 °C to +85 °C), 5 V ±10% supply, and automatic CE-controlled power-down mode. It supports independent byte-wide writes via BHE/ BLE and operates in 44-pin TSOP II package for space-constrained embedded memory buffering.

For engineers reviewing the CY7C1021BN-15ZXIT datasheet, CY7C1021BN-15ZXIT pinout, CY7C1021BN-15ZXIT application, or CY7C1021BN-15ZXIT equivalent, key selection criteria include tAA = 15 ns read timing, ISB2 ≤ 10 mA standby current (CMOS inputs), dual-byte enable control, and automotive-grade thermal resistance (θJA = 76.89 °C/W in TSOP II).

Technical Context

The CY7C1021BN-15ZXIT implements a synchronous, non-volatile-independent SRAM array organized as 65,536 × 16 bits with fully decoded address logic and bidirectional I/O1–I/O16 pins. Its read/write control relies on active-low CE, WE, OE, BHE, and BLE signals with defined setup/hold and transition timing per JEDEC-compliant AC test conditions.

It features automatic power-down when CE is HIGH, reducing ICC to ≤10 mA (ISB2) under CMOS input conditions. Byte-select architecture enables partial-word writes without disturbing adjacent bytes - critical for real-time data logging and FIFO management where word-aligned access is not required.

Key Specifications

Pinout & Package

44-pin TSOP II (Thin Small Outline Package, Type II), 400-mil body width, 0.8 mm pitch, JEDEC MO-141AC compliant. Dual VCC/VSS configuration improves noise immunity and reduces ground bounce in high-speed parallel bus operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS6C1008-15TIN and IS61LV1024-15K, the CY7C1021BN-15ZXIT uniquely delivers industrial-grade thermal performance, true dual-byte write capability, and ultra-low standby current - making it optimal for mission-critical embedded buffering where reliability, partial-word efficiency, and power predictability are mandatory.

Availability

CY7C1021BN-15ZXIT is available at Aetrix Electronics and suitable for industrial PLC data buffering, automotive ECU calibration storage, and telecom line card packet buffering requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CY7C1021BN-15ZXIT 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 markets, with headquarters in San Jose, CA.

The CY7C1021BN series targets applications needing fast, low-power, pin-compatible SRAM replacements for legacy 5 V systems - especially where byte-select control and extended temperature operation are essential.

FAQ

Is CY7C1021BN-15ZXIT compatible with 3.3 V logic interfaces?

No. The CY7C1021BN-15ZXIT requires a 5 V ±10% supply and specifies VIH = 2.2 V minimum and VIL = 0.8 V maximum. Direct connection to 3.3 V controllers risks violating input voltage thresholds and may cause undefined behavior or increased leakage. Level-shifting circuitry is required for interoperability.

Does this SRAM retain data when VCC drops below specification?

No. As a volatile CMOS SRAM, CY7C1021BN-15ZXIT loses stored data when VCC falls below 4.5 V (5 V –10%). It has no internal battery or capacitor backup. Data retention requires continuous regulation within the specified operating range or use of an external hold-up capacitor sized per worst-case current draw and droop time.

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

Yes. When both BHE and BLE are LOW, all 16 I/O pins (I/O1–I/O16) are enabled for concurrent read or write. This matches standard 16-bit bus operation and eliminates the need for two separate cycles to access a full word - confirmed by the Truth Table on page 11 of the datasheet.

What is the maximum sustained write frequency supported?

The device supports continuous write cycles at up to 66.7 MHz (tWC = 15 ns minimum), provided address, data, CE, WE, and byte-enable signals meet all setup/hold timing requirements. Sustained operation at this rate requires careful PCB layout to control skew and maintain signal integrity on all 36 control/data lines.