Cypress Semiconductor Corp CY7C2568KV18-450BZC

Overview

CY7C2568KV18 from Cypress Semiconductor is a 72-Mbit DDR II+ SRAM configured as 4M × 18, operating at up to 450 MHz with 2.5-cycle read latency, on-die termination (ODT), and HSTL I/O. It delivers 1100 MT/s data throughput via double-data-rate interface and supports precise timing with dual K/K clocks and echo clocks CQ/CQ. Used in high-bandwidth networking and packet buffering applications where deterministic latency and signal integrity are critical.

For engineers reviewing the CY7C2568KV18 datasheet, CY7C2568KV18 pinout, CY7C2568KV18 application, or CY7C2568KV18 equivalent, key selection criteria include burst depth (2-word), ODT support for D/BWS/K inputs, QVLD timing alignment with echo clocks, and compatibility with 1.4–1.8 V I/O supply rails in 165-ball FBGA packaging.

Technical Context

This device implements a synchronous pipelined SRAM core with DDR II+ architecture, using rising edges of complementary K and K clocks for address latching, write data registration, and read data output. Internal self-timed writes eliminate external write pulse control, while the PLL ensures accurate data placement relative to echo clocks.

The 4M × 18 organization maps to two 2M × 18 arrays, with BWS[1:0] enabling byte-selective writes across 18-bit data width. DOFF pin configures read latency: HIGH enables 2.5-cycle mode; LOW reverts to 1-cycle DDR I–compatible operation. ODT is programmable via ODT pin and calibrated against ZQ reference resistor.

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, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C2568KV18-500BZC, this -450BZC variant trades 50 MHz bandwidth for relaxed timing margins and lower power (650 mA vs. 700 mA at 450 MHz). Against AS7C3256A-15JCIN, it delivers >10× higher throughput and deterministic DDR timing but requires full DDR PHY support and careful impedance-controlled routing.

Availability

CY7C2568KV18-450BZC is available at Aetrix Electronics and suitable for packet buffering in network switches, line-card memory in telecom infrastructure, and high-speed test equipment requiring stable component supply across extended production lifecycles.

Supply support for CY7C2568KV18-450BZC 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 industrial, automotive, and communications markets, with emphasis on signal integrity and timing precision.

This device belongs to the QDR II+/DDR II+ SRAM product line, engineered specifically for deterministic-latency, high-bandwidth buffering in packet-switched and real-time signal processing systems where burst efficiency and on-die signal conditioning are essential.

FAQ

What is the function of the DOFF pin on CY7C2568KV18-450BZC?

The DOFF (Double-Off) pin selects read latency mode: when asserted HIGH, it enables 2.5-cycle DDR II+ operation; when LOW, the device behaves like a standard DDR I SRAM with 1-cycle latency. This pin is sampled at power-up and remains static during operation - it is not dynamically reconfigurable. Its state determines internal timing paths and must be set before initialization completes.

How does on-die termination (ODT) work on this SRAM?

ODT provides programmable termination resistance (175–350 Ω range) on D[17:0], BWS[1:0], and K/K inputs, calibrated against the external ZQ resistor. The ODT pin selects resistance range (LOW = lower range), and termination is enabled automatically during active cycles. No external resistors are needed, reducing PCB layer count and improving signal fidelity at 450 MHz clock rates.

Can CY7C2568KV18-450BZC operate with VDDQ = 1.5 V?

Yes - the device supports VDDQ from 1.4 V to 1.8 V, including 1.5 V nominal. At 1.5 V, AC timing parameters (e.g., tAC, tHZ) scale linearly per datasheet specifications, and HSTL Class I compliance is maintained. Core VDD must remain at 1.8 V ± 0.1 V regardless of VDDQ setting, as it powers the SRAM array and internal logic independently.

What is the role of CQ and CQ echo clocks?

CQ and CQ are source-synchronous output clocks driven edge-aligned with DQ[17:0] data transitions. They eliminate timing skew between clock and data paths in point-to-point connections, allowing receivers to latch data without complex phase alignment circuits. Unlike system clocks, they are not used for input sampling and are only active during read bursts - simplifying clock tree design in high-speed interfaces.