Cypress Semiconductor Corp CY7C25682KV18-450BZC

Overview

CY7C25682KV18-450BZC from Cypress Semiconductor is a 72-Mbit (4M × 18) DDR II+ synchronous pipelined SRAM with two-word burst architecture, 2.5-cycle read latency at 450 MHz, on-die termination (ODT), and HSTL I/O interfaces operating at VDDQ = 1.4–1.8 V. It uses dual input clocks (K/K) and echo clocks (CQ/CQ) for precise DDR timing and data capture in high-speed memory subsystems, deployed in network packet buffers and FPGA co-processor caches.

For engineers reviewing the CY7C25682KV18-450BZC datasheet, CY7C25682KV18-450BZC pinout, CY7C25682KV18-450BZC application, or CY7C25682KV18-450BZC equivalent, key selection criteria include 450 MHz maximum clock frequency, 2.5-cycle vs. 1-cycle configurable read latency via DOFF pin, ODT support for D/BWS/K/K inputs, 165-ball FBGA package, and QVLD-synchronized valid-data indication.

Technical Context

This device implements a synchronous pipelined SRAM core with DDR II+ interface logic, where all address, control, and data signals are registered on rising edges of K and K clocks. Read and write operations execute as two-word bursts, with each address location delivering two sequential 18-bit words on alternating K/K edges.

The integrated PLL ensures accurate data placement relative to echo clocks CQ/CQ, while ODT enables programmable termination (175–350 Ω range) for D[17:0], BWS[1:0], and K/K inputs using external ZQ resistor. DOFF pin selects between 2.5-cycle (HIGH) and 1-cycle (LOW) read latency modes, maintaining functional compatibility with DDR I systems.

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-speed synchronous SRAM applications.

Compared with CY7C25682KV18-450BZC, the -500BZC offers higher bandwidth at increased power and layout complexity, while the AS7C3256PFS-15JC lacks DDR functionality entirely-making it unsuitable for any application requiring burst transfers or impedance-controlled high-speed signaling.

Availability

CY7C25682KV18-450BZC is available at Aetrix Electronics and suitable for network packet buffers, FPGA co-processor caches, and telecom baseband memory requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.

Supply support for CY7C25682KV18-450BZC 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 networking, automotive, and industrial applications, with emphasis on signal integrity and system-level integration.

CY7C25682KV18 belongs to the QDR II+ SRAM product line, engineered specifically for deterministic, low-latency, high-bandwidth memory interfacing in FPGA- and ASIC-based data-path systems where DDR timing predictability is critical.

FAQ

What is the function of the DOFF pin on CY7C25682KV18-450BZC?

The DOFF (Disable Off-mode) pin configures read latency mode: when asserted HIGH, the device operates in DDR II+ mode with 2.5-cycle read latency; when LOW, it reverts to DDR I-compatible 1-cycle latency. This pin is sampled at power-up and remains latched, enabling hardware-selectable performance vs. compatibility trade-offs without firmware intervention.

How does On-Die Termination (ODT) work on this SRAM?

ODT provides programmable termination resistance (175–350 Ω range) for D[17:0], BWS[1:0], K, and K inputs using an external ZQ resistor. The ODT pin selects between RQ/3.33 (LOW) or RQ/1.66 (HIGH) scaling. This eliminates discrete termination resistors, reduces PCB layer count, and improves signal integrity at 450 MHz without sacrificing routing flexibility.

Can CY7C25682KV18-450BZC be used with a 1.5 V I/O supply?

Yes - the device supports VDDQ = 1.4 V to 1.8 V, explicitly including 1.5 V operation. HSTL Class I output drivers and input receivers are fully compliant at 1.5 V, and DC/AC specifications (including setup/hold times and ODT calibration) are validated across this full range per datasheet Table 20 and Figure 22.

What is the role of CQ and CQ echo clocks?

CQ and CQ are free-running, phase-aligned copies of the K and K input clocks, generated internally by the device. They serve as dedicated, low-skew strobes for capturing DQ[17:0] outputs - eliminating the need for board-level routing of separate read strobes and removing inter-SRAM skew in depth-expanded configurations.