Cypress Semiconductor Corp CY7C1518AV18-250BZI

Overview

CY7C1518AV18 from Cypress Semiconductor is a 72-Mbit (4 M × 18) DDR-II synchronous SRAM with two-word burst architecture, 300-MHz clock support, 1.8-V core supply, and HSTL I/O. It operates with 1.5-cycle read latency when DLL is enabled and supports echo clocks (CQ/CQ) for precise high-speed data capture in networking and telecom buffer applications.

For engineers reviewing the CY7C1518AV18 datasheet, CY7C1518AV18 pinout, CY7C1518AV18 application, or CY7C1518AV18 equivalent, key selection criteria include DDR-II timing compliance, 165-ball FBGA package compatibility, dual-clock (K/K and C/C) interface requirements, and JTAG 1149.1 test port integration for system-level validation.

Technical Context

This SRAM implements a synchronous pipelined architecture with internal burst counter driven by A0, latching addresses on alternate rising edges of K/K clocks and registering write data on both K and K edges. Read data is output synchronously on C/C (or K/K in single-clock mode), tightly aligned to echo clocks CQ/CQ for zero-skew capture.

The device integrates a delay-locked loop (DLL) for accurate data placement, supports programmable output impedance via ZQ calibration, and provides byte-write select (BWS0/BWS1) for granular 9-bit writes. JTAG 1149.1 boundary scan enables production testability without requiring external test fixtures.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 15 mm × 17 mm × 1.4 mm body height, RoHS-compliant, with 1.0 mm ball pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DDR-II SRAM applications.

Compared with IS45S32800J-3BLI and MT47H64M16HR-3:G, CY7C1518AV18 delivers deterministic sub-2-cycle latency, built-in DLL for timing margin recovery, and echo clocks for simplified high-speed capture-critical for real-time packet buffering and baseband processing where jitter and setup/hold violations must be eliminated.

Availability

CY7C1518AV18 is available at Aetrix Electronics and suitable for high-speed packet buffering, baseband processing memory, network processor lookaside memory, and industrial real-time control buffer applications requiring stable component supply and long-term lifecycle support.

Supply support for CY7C1518AV18 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 communications, computing, and industrial systems, with focus on signal integrity and timing-critical applications.

CY7C1518AV18 belongs to Cypress's DDR-II SRAM product line, engineered specifically for deterministic, low-latency, high-throughput buffering in telecom infrastructure and real-time digital signal processing systems.

FAQ

What is the function of the DOFF pin on CY7C1518AV18?

The DOFF (DLL Turn Off) pin is an active-low input that disables the internal delay-locked loop. When pulled low, the device reverts to DDR-I timing with 1-cycle read latency and a maximum operating frequency of 167 MHz. This mode is used for system-level timing margin testing or fallback operation under voltage/temperature stress, and requires updated AC timing parameters from the datasheet's DLL-off section.

How does the ZQ pin affect output drive strength?

The ZQ pin connects to an external resistor to ground (typically 240 Ω) to calibrate the output driver impedance to 0.2 × R_Q, resulting in ~48 Ω for standard HSTL termination. This calibration ensures consistent signal rise/fall times and minimizes reflections on 50 Ω transmission lines. Leaving ZQ unconnected or tying it to GND violates specifications and causes undefined output impedance behavior.

Can CY7C1518AV18 operate without C and C clocks?

Yes - the device supports single-clock mode where K and K serve as both input and output clocks. In this configuration, read data is driven on K/K edges instead of C/C, and echo clocks CQ/CQ are generated relative to K/K. However, this sacrifices the flight-time deskewing capability provided by independent C/C, limiting maximum reliable data rate to ~250 MHz in typical layouts.

What is the role of BWS0 and BWS1 in write operations?

BWS0 and BWS1 are active-low byte write select inputs that control which 9-bit segments of DQ[17:0] are written during a burst. BWS0 governs DQ[8:0], BWS1 governs DQ[17:9]. When asserted, they enable writing to their respective byte lanes; when deasserted, those bits retain prior values. This enables atomic partial-word updates essential for status register maintenance in real-time control applications.