Cypress Semiconductor Corp CY7C25682KV18-550BZXI

Overview

CY7C25682KV18 from Cypress Semiconductor is a 72-Mbit (4M × 18) synchronous pipelined DDR II+ SRAM with two-word burst architecture, 2.5-cycle read latency (DOFF = HIGH), 550 MHz clock frequency, and on-die termination (ODT) for D[x:0], BWS[x:0], and K/K inputs. It operates at core VDD = 1.8 V ± 0.1 V and I/O VDDQ = 1.4–1.8 V, and is packaged in a 165-ball FBGA (13 × 15 × 1.4 mm). It serves as high-bandwidth buffer memory in networking line cards requiring precise DDR timing and echo-clock–synchronized data capture.

For engineers reviewing the CY7C25682KV18 datasheet, CY7C25682KV18 pinout, CY7C25682KV18 application, or CY7C25682KV18 equivalent, key selection criteria include DDR II+ burst timing compliance, ODT configuration via ZQ/ODT pins, QVLD-synchronized output validity, and compatibility with 550 MHz K/K clock pairs driving HSTL I/O interfaces in depth-expanded SRAM systems.

Technical Context

This device implements a synchronous pipelined SRAM core with dual-edge DDR interface logic: addresses are latched on alternate rising edges of K, write data is registered on both K and K rising edges, and read data is driven on both K and K rising edges. Each access delivers two sequential 18-bit words, enabling bandwidth efficiency without increasing address bus frequency.

The internal architecture includes a PLL for accurate data placement, echo clocks (CQ/CQ) aligned to K/K for simplified high-speed data capture, and programmable ODT ranges selected by the ODT pin during power-up initialization-supporting RQ/3.33 (low range) or RQ/1.66 (high range) termination impedance matching.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 13 mm × 15 mm × 1.4 mm body height, RoHS-compliant Pb-free option available.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-bandwidth synchronous SRAM applications.

Compared with CY7C25682KV18-450BZXI, the -550BZXI variant delivers 22% higher bandwidth and tighter timing margins for high-end networking; AS7C3256A-15JC lacks DDR, ODT, and burst capability entirely - it serves fundamentally different system roles and requires full interface redesign.

Availability

CY7C25682KV18 is available at Aetrix Electronics and suitable for high-speed network line cards, packet buffering in switch ASICs, telecom baseband processing, and industrial real-time data loggers requiring stable component supply and long-term obsolescence management.

Supply support for CY7C25682KV18 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 specializing in memory, microcontrollers, and connectivity solutions for embedded systems.

CY7C25682KV18 belongs to Cypress's QDR II+/DDR II+ SRAM product line, engineered specifically for high-throughput, low-latency buffering in networking, telecom, and high-performance computing applications demanding deterministic DDR timing and integrated signal integrity features.

FAQ

What is the function of the DOFF pin on CY7C25682KV18?

The DOFF (Double-Off) pin configures read latency mode: when asserted HIGH, the device operates in DDR II+ mode with 2.5-cycle read latency; when LOW or tied to VSS, it reverts to DDR I mode with 1-cycle latency. This pin is sampled at power-up and remains static during operation - it does not support dynamic switching mid-operation.

How does on-die termination (ODT) work on CY7C25682KV18?

ODT is enabled via the ODT pin and calibrated using an external resistor (RQ) connected to the ZQ pin. A LOW on ODT selects RQ/3.33 termination (175–350 Ω range); HIGH selects RQ/1.66 (175–250 Ω). ODT applies to D[17:0], BWS[1:0], and K/K inputs - eliminating external resistors and reducing board-level signal integrity complexity.

Can CY7C25682KV18 be used in depth-expanded memory configurations?

Yes - its synchronous tri-state control, QVLD signaling, and echo clocks (CQ/CQ) are explicitly designed for depth expansion. When a read is deselected, outputs tri-state on the next K rising edge, enabling seamless handoff between devices without wait states. CQ/CQ alignment ensures consistent capture timing across multiple SRAMs in parallel depth stacks.

What is the role of the CQ and CQ pins?

CQ and CQ are free-running echo clocks synchronized to the K input clock. They are edge-aligned with valid data on DQ[17:0] and serve as source-synchronous capture clocks for the receiving controller. Unlike forwarded clocks, they track K skew and jitter, enabling robust data capture at 550 MHz without complex deskew circuitry or manual timing margining.