Infineon Technologies CY7C1268V18-400BZXC

Overview

CY7C1268V18 from Cypress Semiconductor is a 36-Mbit (2M × 18) synchronous pipelined SRAM with DDR-II+ architecture, operating at 400 MHz with 2.5-cycle read latency and dual-edge DDR data transfer at 800 Mbps. It features HSTL I/O, 1.8V core supply, 1.4–1.8V I/O supply, and echo clocks (CQ/CQ) for precise high-speed data capture in memory subsystems. Used in network packet buffers and high-throughput FPGA co-processor interfaces.

For engineers reviewing the CY7C1268V18 datasheet, CY7C1268V18 pinout, CY7C1268V18 application, or CY7C1268V18 equivalent, key selection criteria include burst depth (2-word), DDR timing alignment via K/K clocks, QVLD validity signaling, DLL-enabled data placement accuracy, and FBGA-165 package compatibility with high-density PCB layouts.

Technical Context

The CY7C1268V18 implements a synchronous pipelined architecture where address and control signals are registered on rising edges of K and K clocks. Read data bursts two 18-bit words sequentially, driven on both K and K rising edges with QVLD edge-aligned to CQ/CQ outputs.

Its internal 2M × 18 array uses dual-clock DDR timing with Delay Lock Loop (DLL) for sub-cycle data placement accuracy. Write operations employ synchronous self-timed write circuitry with BWS[1:0] byte-select control, and impedance matching is managed via ZQ pin referenced to external resistor or VDDQ.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 15 mm × 17 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 AS7C362000B-400BIN and IS61WV204818BLL-400BLI, the CY7C1268V18 uniquely integrates DLL-based data alignment, QVLD validity signaling, and HSTL I/O with ZQ calibration-enabling robust 400 MHz operation in tightly timed, multi-device memory subsystems without external timing compensation.

Availability

CY7C1268V18 is available at Aetrix Electronics and suitable for network packet buffering, FPGA co-processor caching, telecom baseband memory, and high-speed test equipment requiring stable component supply and long-lifecycle support.

Supply support for CY7C1268V18 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 demanding embedded and communications applications.

The CY7C1268V18 belongs to Cypress's DDR-II+ SRAM product line, engineered specifically for ultra-low-latency, high-bandwidth memory subsystems in networking, wireless infrastructure, and test instrumentation.

FAQ

What is the function of the DOFF pin on CY7C1268V18?

The DOFF (DLL Turn Off) pin is an active-low control that disables the internal Delay Lock Loop. When asserted, the device reverts to DDR-I timing mode with reduced maximum frequency (≤167 MHz) and relaxed setup/hold requirements. For normal DDR-II+ operation at 400 MHz, DOFF must be pulled high via ≤10 kΩ resistor to VDDQ.

How does the ZQ pin affect output impedance calibration?

The ZQ pin connects to an external resistor (RQ) tied to ground, enabling on-die calibration of CQ, CQ, and DQ[17:0] output drivers to 0.2 × RQ. This achieves precise HSTL-compatible impedance matching to the PCB trace. Alternatively, tying ZQ to VDDQ enables minimum-impedance mode; ZQ must never be left floating or connected to VSS.

Can CY7C1268V18 operate with only the K clock (not K)?

No. The CY7C1268V18 requires both K and K clocks for full DDR-II+ functionality. K and K are complementary inputs used to latch data and control signals on alternating edges. Omitting K violates timing specifications and prevents correct burst read/write operation, as data is sampled and driven on both clock edges.

What is the role of BWS[1:0] during write operations?

BWS[1:0] are active-low byte write select inputs controlling which 9-bit portion of DQ[17:0] is written during each half of the 2-word burst. BWS0 enables DQ[8:0], BWS1 enables DQ[17:9]. Both must be asserted to write the full 18-bit word; deselecting either preserves the corresponding byte in memory, enabling partial-word updates without read-modify-write cycles.