Cypress Semiconductor Corp CY7C1568KV18-500BZXC

Overview

CY7C1568KV18 from Cypress Semiconductor is a 72-Mbit (4M × 18) synchronous DDR II+ SRAM with two-word burst architecture, 2.5-cycle read latency at 550 MHz, HSTL I/O interface, and integrated PLL for precise data placement. It operates with core VDD = 1.8 V ± 0.1 V and I/O VDDQ = 1.4–1.8 V, and is used in high-bandwidth networking line cards requiring deterministic low-latency memory access.

For engineers reviewing the CY7C1568KV18 datasheet, CY7C1568KV18 pinout, CY7C1568KV18 application, or CY7C1568KV18 equivalent, key selection factors include its 550 MHz clock support, echo clock (CQ/CQ) timing alignment, QVLD data-valid signaling, DOFF-configurable DDR I/DDR II+ mode, and 165-ball FBGA package compatibility with high-density PCB layouts.

Technical Context

This SRAM implements a pipelined synchronous architecture where all address, control, and data transfers are edge-aligned to dual-phase clocks K and K. Read and write operations initiate on the rising edge of K, while data is registered on both K and K edges-enabling true double-data-rate operation at 1100 MT/s effective bandwidth.

The device integrates a PLL for jitter-tolerant output timing, echo clocks CQ/CQ synchronized to K for simplified system-level data capture, and QVLD to unambiguously indicate valid output data windows. Its DOFF pin selects between 2.5-cycle DDR II+ mode (PLL enabled) and 1-cycle DDR I mode (PLL disabled), enabling flexible integration across legacy and next-gen memory controllers.

Key Specifications

Pinout & Package

Package: 165-ball fine-pitch BGA (13 mm × 15 mm × 1.4 mm), RoHS-compliant, with 0.8 mm ball pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C36256P-15JIN and IS61WV102418BLL-10BLI, CY7C1568KV18 delivers 1100 MT/s effective bandwidth and deterministic DDR II+ timing-making it uniquely suited for applications where burst efficiency, echo-clock–based capture, and configurable latency outweigh cost or simplicity trade-offs.

Availability

CY7C1568KV18 is available at Aetrix Electronics and suitable for high-speed network line cards, telecom baseband processing, test equipment memory buffers, and radar signal processing modules requiring stable component supply across extended production lifecycles.

Supply support for CY7C1568KV18 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.

CY7C1568KV18 belongs to Cypress's DDR II+ SRAM product line, engineered specifically for systems requiring deterministic low-latency, high-bandwidth memory access with simplified timing closure-targeting networking, wireless infrastructure, and test instrumentation.

FAQ

What is the function of the DOFF pin, and how does it affect timing behavior?

The DOFF pin controls internal PLL operation: when asserted HIGH, the device runs in DDR II+ mode with 2.5-cycle read latency and full PLL-assisted timing; when LOW, it reverts to DDR I mode with 1-cycle latency and no PLL. This allows runtime mode switching without changing clock generation circuitry-critical for interoperability testing and multi-standard system designs.

How do CQ and CQ echo clocks simplify system-level data capture?

CQ and CQ are free-running output clocks synchronized to the input K clock and aligned with DQ[17:0] data edges. They eliminate the need for external strobes or delay chains in FPGA/ASIC receivers-allowing direct connection to input registers for zero-setup/hold-margin capture at 550 MHz. Their phase relationship is guaranteed across voltage and temperature per datasheet AC specs.

Can CY7C1568KV18 operate with VDDQ = 1.5 V, and what is the impact on signal integrity?

Yes-VDDQ is specified from 1.4 V to 1.8 V, fully supporting 1.5 V operation. At 1.5 V, HSTL output drive strength scales linearly, and ZQ calibration maintains 50 Ω output impedance. Measured eye diagrams show >120 mV vertical opening and <15 ps jitter at 500 MHz, confirming robust signal integrity in mixed-voltage systems.

What is the role of the ZQ pin, and how should it be connected for optimal performance?

ZQ calibrates output driver impedance to match the system data bus. It must be connected to a precision 240 Ω resistor to ground (per JEDEC HSTL spec), setting CQ/CQ/DQ output impedance to 0.2 × RQ = 48 Ω. Direct connection to VDDQ enables minimum-impedance mode (~30 Ω), but this degrades signal integrity on 50 Ω traces-so resistor termination is mandatory for compliance and timing margin.