Infineon Technologies CY7C25682KV18-500BZC

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 (when DOFF = HIGH), 550 MHz clock operation, and on-die termination (ODT) for D[x:0], BWS[x:0], and K/K inputs. It delivers 1100 MT/s data throughput via double-data-rate I/O and is used in high-bandwidth networking line cards requiring deterministic low-latency memory access.

For engineers reviewing the CY7C25682KV18 datasheet, CY7C25682KV18 pinout, CY7C25682KV18 application, or CY7C25682KV18 equivalent, key selection criteria include DDR II+ timing compliance, echo clock (CQ/CQ) synchronization for source-synchronous data capture, ODT configuration via ZQ/ODT pins, and compatibility with 1.8 V core / 1.4–1.8 V I/O supply rails.

Technical Context

This device implements a synchronous pipelined SRAM core with dual-edge DDR interface logic, where all address, control, and data signals are registered on rising edges of complementary clocks K and K. Read data is driven on both K and K edges with precise alignment to echo clocks CQ/CQ, enabling reliable source-synchronous capture without board-level timing margining.

The internal architecture includes two 2M × 18 arrays, byte-write select (BWS0/BWS1) for 9-bit granularity writes, QVLD for cycle-accurate data validity indication, and a PLL for accurate data placement. DOFF pin selects between DDR II+ mode (2.5-cycle latency) and DDR I mode (1-cycle latency), allowing runtime latency tuning.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 13 mm × 15 mm × 1.4 mm body, 0.8 mm ball pitch, bottom thermal pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C25682KV18-450BZC, the -500BZC offers 100 MHz higher bandwidth and 110 mA higher current headroom for sustained bursts; versus AS7C3256B-15JCIN, it delivers 72× more density, 73× higher throughput, and deterministic source-synchronous timing essential for modern packet-processing pipelines.

Availability

CY7C25682KV18 is available at Aetrix Electronics and suitable for high-bandwidth networking infrastructure, telecom line card design, and industrial real-time control systems requiring stable component supply and long-term lifecycle assurance.

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) designs high-performance memory and programmable solutions for networking, automotive, and industrial applications, with emphasis on signal integrity and system-level timing robustness.

CY7C25682KV18 belongs to the QDR II+ SRAM product line, engineered specifically for deterministic, low-jitter, high-throughput memory interfacing in packet-forwarding engines, baseband processors, and test instrumentation.

FAQ

What is the function of the DOFF pin, and how does it affect timing?

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, it reverts to DDR I mode with 1-cycle latency. This is a static configuration set at power-up and affects internal pipeline staging - no dynamic switching is supported during operation. Latency mode determines minimum clock-to-output delay and burst alignment.

How is on-die termination (ODT) calibrated and controlled?

ODT is calibrated using the ZQ pin connected to a 240 Ω resistor to ground, which sets the reference impedance. The ODT pin selects resistance range: LOW selects RQ/3.33 (~72 Ω for 240 Ω ZQ), HIGH selects RQ/1.66 (~144 Ω). Calibration occurs automatically during power-up initialization and remains fixed until next reset; no software register access is required.

Can CY7C25682KV18 interface directly with Xilinx Ultrascale+ FPGAs?

Yes - its HSTL Class I I/O, 550 MHz DDR timing, echo clocks (CQ/CQ), and QVLD signal are fully compatible with Xilinx Ultrascale+ memory interfaces. The device meets all AC timing requirements for MIG-generated DDR controllers targeting QDR II+ protocols, including t_DS, t_DH, and t_QVLD specifications in the 001-66483 datasheet.

What is the role of the LD (Load) signal in burst transaction sequencing?

LD is the command strobe that initiates each burst transaction. Sampled on the rising edge of K, it latches the current address and R/W state to begin a two-word read or write. LD must meet strict setup/hold times relative to K; it is not a continuous enable but a per-burst trigger - one LD assertion yields exactly two data words transferred, regardless of subsequent K edges.