Cypress Semiconductor Corp CY7C1268XV18-633BZXC

Overview

CY7C1268XV18-633BZXC from Infineon Technologies (formerly Cypress) is a 36-Mbit DDR II+ Xtreme SRAM with 2 M × 18 organization, 633 MHz clock frequency, 2.5-cycle read latency, and HSTL I/O interface operating at 1.4–1.6 V VDDQ. It implements two-word burst architecture with echo clocks (CQ/CQ) and QVLD for precise high-speed data capture in memory subsystems of network switches and telecom line cards.

For engineers reviewing the CY7C1268XV18-633BZXC datasheet, CY7C1268XV18-633BZXC pinout, CY7C1268XV18-633BZXC application, or CY7C1268XV18-633BZXC equivalent, key selection criteria include DDR II+ timing compliance, 165-ball FBGA (13 × 15 × 1.4 mm) mechanical fit, DOFF-controlled latency mode switching, and JTAG 1149.1 test access support.

Technical Context

This SRAM integrates a synchronous pipelined core with dual-edge DDR interface logic, PLL-based clock alignment, and echo-clock–driven output timing. All address, control, and data signals are registered on rising edges of complementary K/K clocks, enabling deterministic 1266 MT/s data transfer at 633 MHz.

The device supports two operational modes via DOFF: DDR II+ mode (DOFF = HIGH) delivers 2.5-cycle read latency with full 633 MHz bandwidth; DDR I mode (DOFF = LOW) reduces latency to 1 cycle but limits max frequency to 167 MHz. Internal impedance tuning via ZQ pin enables system-level signal integrity optimization.

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 construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1268XV18-553BZXC, the -633BZXC delivers 14% higher bandwidth and tighter timing margins; versus AS7C362000B-166BIN, it provides synchronous DDR operation, echo-clock timing, and 6× peak throughput - making it essential for modern high-speed data path applications.

Availability

CY7C1268XV18-633BZXC is available at Aetrix Electronics and suitable for network switch buffering, telecom line card memory, high-performance test equipment, and radar signal processing requiring stable component supply across extended product lifecycles.

Supply support for CY7C1268XV18-633BZXC 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

Infineon Technologies acquired Cypress Semiconductor in 2020 and maintains its high-performance memory portfolio, including DDR II+ Xtreme SRAMs, with global manufacturing, quality, and support infrastructure.

CY7C1268XV18 belongs to the Xtreme SRAM product line, engineered specifically for deterministic, low-jitter, high-bandwidth memory subsystems in networking, telecom, and test instrumentation where DDR timing precision and echo-clock synchronization are critical.

FAQ

What is the function of the DOFF pin on CY7C1268XV18-633BZXC?

The DOFF pin controls internal PLL operation: when asserted HIGH, the device operates in DDR II+ mode with 2.5-cycle read latency and 633 MHz capability; when LOW, it reverts to DDR I mode with 1-cycle latency and 167 MHz maximum frequency. This enables hardware-compatible dual-mode operation without changing PCB layout or firmware timing parameters.

How does the ZQ pin affect signal integrity in high-speed designs?

The ZQ pin connects to an external resistor to ground to calibrate internal output driver impedance, setting CQ, CQ, and DQ output strength to 0.2 × RQ. This matches transmission line impedance (typically 50 Ω), minimizing reflections and ensuring clean eye diagrams at 1266 MT/s - eliminating need for discrete series termination resistors.

Can CY7C1268XV18-633BZXC be used without the PLL enabled?

Yes - asserting DOFF LOW disables the PLL and places the device in DDR I mode, supporting 1-cycle read latency up to 167 MHz. In this mode, timing specifications differ significantly from DDR II+ mode, and echo clocks (CQ/CQ) remain functional but aligned to base clock rather than PLL-adjusted phase.

What is the role of QVLD in system-level data capture?

QVLD is a synchronous output that transitions edge-aligned with CQ and CQ to indicate when DQ[17:0] data is valid and stable. System logic uses QVLD - not clock edges alone - to latch read data, preventing metastability and ensuring reliable capture even under PVT variation or jitter conditions.