Cypress Semiconductor Corp CY7C1268KV18-400BZXC

Overview

CY7C1268KV18 from Cypress Semiconductor is a 36-Mbit (2 M × 18) DDR II+ synchronous pipelined SRAM with 2.5-cycle read latency, 550 MHz clock support, and HSTL I/O interface operating at 1.4 V to 1.8 V. It delivers 1100 MT/s data throughput via double-data-rate transfers synchronized to K/K clocks and integrates echo clocks (CQ/CQ) and QVLD for precise high-speed data capture in networking and test equipment memory buffers.

For engineers reviewing the CY7C1268KV18 datasheet, CY7C1268KV18 pinout, CY7C1268KV18 application, or CY7C1268KV18 equivalent, key selection considerations include its 165-ball FBGA package, PLL-controlled timing alignment, DOFF-selectable DDR I/DDR II+ mode, and synchronous burst write capability with byte-write select (BWS0/BWS1) for partial-word updates.

Technical Context

This SRAM implements a two-word burst architecture where each address access retrieves two consecutive 18-bit words on alternating rising edges of K and K clocks. Internal pipelining enables back-to-back read initiation every K cycle, while synchronous self-timed writes eliminate external write-strobe timing constraints.

The device uses a phase-locked loop (PLL) to align output data with echo clocks CQ/CQ, achieving ±0.45 ns data valid window relative to clock edges. DOFF pin selection determines operation mode: HIGH enables DDR II+ with 2.5-cycle latency and up to 550 MHz; LOW disables PLL and reverts to DDR I timing with 1-cycle latency and ≤167 MHz maximum frequency.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 13 mm × 15 mm × 1.4 mm body height, RoHS-compliant, with thermal pad exposed on underside.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C33618A-400BIN and IS61WV102418BLL-10BLI, CY7C1268KV18 uniquely delivers programmable DDR latency, echo-clock–assisted data capture, and HSTL signaling - making it irreplaceable in systems requiring guaranteed 550 MHz burst throughput with sub-nanosecond timing closure.

Availability

CY7C1268KV18 is available at Aetrix Electronics and suitable for telecom line cards, high-speed test equipment, network packet processors, and medical imaging systems requiring stable component supply across extended product lifecycles.

Supply support for CY7C1268KV18 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.

CY7C1268KV18 belongs to Cypress's QDR II+/DDR II+ SRAM product line, engineered specifically for deterministic, low-jitter memory buffering in packet-switched networks and high-speed instrumentation where burst throughput and timing predictability are critical.

FAQ

What is the function of the DOFF pin on CY7C1268KV18?

The DOFF pin controls the internal PLL: when asserted HIGH, it enables DDR II+ mode with 2.5-cycle read latency and up to 550 MHz operation; when LOW, it disables the PLL and reverts the device to DDR I timing with 1-cycle latency and a maximum frequency of 167 MHz. This allows runtime mode switching without changing external clock sources or layout.

How does the QVLD signal improve system timing margin?

QVLD is edge-aligned with the echo clocks CQ and CQ and asserts precisely when DQ[17:0] data is valid. Unlike fixed-delay approaches, QVLD eliminates setup/hold uncertainty by providing a synchronous, per-burst validity indicator - enabling FPGA receivers to sample data with zero added timing margin in high-speed designs.

Can CY7C1268KV18 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, HSTL output drive strength remains compliant with Class I specifications, and AC timing parameters (e.g., tAC, tHZ) are guaranteed per the datasheet's 1.5 V operating condition tables, provided VDD remains at 1.8 V ± 0.1 V.

What is the purpose of the ZQ pin and how must it be connected?

ZQ enables output impedance calibration: connecting a 240 Ω resistor from ZQ to ground sets CQ, CQ, and DQ output impedance to 48 Ω (0.2 × 240 Ω). Alternatively, tying ZQ to VDDQ enables minimum-impedance mode. ZQ must never be left floating or connected to GND directly - doing so disables calibration and risks signal integrity failure.