Cypress Semiconductor Corp CY7C2568XV18-633BZXC

Overview

CY7C2568XV18-633BZXC from Cypress Semiconductor is a 72-Mbit (4 M × 18) DDR II+ Xtreme SRAM with two-word burst architecture, 2.5-cycle read latency at 633 MHz clock frequency, on-die termination (ODT) for DQ/BWS/K/K inputs, and HSTL I/O interface operating at 1.4–1.6 V VDDQ. It delivers 1266 MT/s data rate in high-bandwidth networking and packet buffering applications.

For engineers reviewing the CY7C2568XV18-633BZXC datasheet, CY7C2568XV18-633BZXC pinout, CY7C2568XV18-633BZXC application, or CY7C2568XV18-633BZXC equivalent, key selection criteria include DDR II+ burst timing, ODT configuration via ZQ/ODT pins, echo clock (CQ/CQ) synchronization, QVLD data validity signaling, and 165-ball FBGA package compatibility with high-speed PCB layout constraints.

Technical Context

This SRAM implements synchronous pipelined read/write operations using dual-edge-aligned K/K clocks: address and control signals latch on K rising edges, while write data registers on both K and K rising edges. Read data outputs are edge-aligned to both K and K, with QVLD indicating valid output timing relative to CQ/CQ.

The device integrates a PLL for precise data placement, supports programmable impedance matching via ZQ pin (0.2 × RQ), and enables configurable read latency (1-cycle DDR I mode when DOFF = LOW; 2.5-cycle DDR II+ mode when DOFF = HIGH). ODT is active only during write cycles and applies to DQ[17:0], BWS[1:0], and K/K inputs.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C2568XV18-633BZXC, the -500BZXC variant trades 21% bandwidth for reduced jitter sensitivity and lower power, while the AS7C3256A lacks DDR timing, ODT, and burst capability-making it incompatible for systems requiring synchronized multi-word transfers or impedance-controlled signaling.

Availability

CY7C2568XV18-633BZXC is available at Aetrix Electronics and suitable for high-speed packet buffering, network switch ASIC interfacing, telecom baseband processing, and test equipment data capture requiring stable component supply and long-term industrial availability.

Supply support for CY7C2568XV18-633BZXC 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 automotive, industrial, and communications markets.

CY7C2568XV18 belongs to the DDR II+ Xtreme SRAM product line, engineered specifically for deterministic, low-latency burst memory in high-speed serial fabric and packet-processing systems.

FAQ

What is the function of the DOFF pin on CY7C2568XV18-633BZXC?

The DOFF (DDR 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 pin is sampled during power-up initialization and remains static during operation, enabling system-level compatibility with multiple controller generations without hardware change.

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

ODT is enabled only during write operations and applies to DQ[17:0], BWS[1:0], and K/K inputs. Its resistance value is selected at power-up based on the ODT pin state and ZQ calibration resistor (RQ): ODT = RQ/3.33 (LOW) or RQ/1.66 (HIGH). This eliminates external termination components and adapts to varying PCB trace impedances without redesign.

Can CY7C2568XV18-633BZXC operate with a 1.5 V VDDQ supply?

Yes - the device specifies VDDQ = 1.4 V to 1.6 V, making 1.5 V nominal operation fully compliant. All HSTL Class I input thresholds and output drive strengths are guaranteed across this range, and ZQ calibration remains accurate since output impedance scales linearly with VDDQ.

What is the purpose of the CQ and CQ echo clocks?

CQ and CQ are free-running, K-synchronized output clocks that align precisely with data transitions on DQ[17:0]. They serve as dedicated capture strobes for receiving systems, removing skew uncertainty between clock and data paths. Unlike traditional DDR strobes, they require no phase alignment circuitry and simplify timing closure in multi-SRAM configurations.