Infineon Technologies CY7C1568KV18-400BZXCT

Overview

CY7C1568KV18-400BZXCT from Cypress Semiconductor is a 72-Mbit (4M × 18) DDR II+ synchronous SRAM with two-word burst architecture, 2.5-cycle read latency, and 400 MHz maximum clock frequency. It operates with core VDD = 1.8 V ± 0.1 V and I/O VDDQ = 1.4 V to 1.8 V, features HSTL-compatible I/O, and uses dual input clocks (K/K) and echo clocks (CQ/CQ) for precise DDR timing in high-speed memory subsystems.

For engineers reviewing the CY7C1568KV18-400BZXCT datasheet, CY7C1568KV18-400BZXCT pinout, CY7C1568KV18-400BZXCT application, or CY7C1568KV18-400BZXCT equivalent, this device supports deterministic low-latency burst reads/writes in networking packet buffers, FPGA co-processor caches, and real-time signal processing pipelines where synchronized DDR timing and QVLD-driven data capture are critical.

Technical Context

The CY7C1568KV18 implements a pipelined synchronous architecture where all address, control, and data signals are registered on rising edges of K and K clocks. Read data is driven on both K and K edges, with QVLD edge-aligned to CQ/CQ for reliable capture without external strobes.

Its DDR II+ mode (DOFF = HIGH) delivers 2.5-cycle read latency at up to 400 MHz, while DOFF = LOW enables DDR I mode (1-cycle latency, ≤167 MHz). The integrated PLL ensures accurate data placement, and ZQ pin enables programmable output impedance matching to system bus termination.

Key Specifications

Pinout & Package

Package: 165-ball fine-pitch ball grid array (FBGA), 13 mm × 15 mm × 1.4 mm, 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 AS7C35128PFS-15TIN and IS61WV102418BLL-10TLI, the CY7C1568KV18-400BZXCT uniquely delivers DDR II+ burst throughput at 400 MHz with hardware-synchronized data capture - making it irreplaceable in applications demanding >1 GB/s sustained memory bandwidth with sub-3 ns timing predictability.

Availability

CY7C1568KV18-400BZXCT is available at Aetrix Electronics and suitable for networking packet buffers, FPGA co-processor caches, real-time video frame buffers, and industrial motion control FIFOs requiring stable component supply across extended product lifecycles.

Supply support for CY7C1568KV18-400BZXCT 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 systems.

This device belongs to Cypress's QDR II+/DDR II+ SRAM product line, engineered specifically for deterministic, high-bandwidth memory interfacing in networking, telecom, and real-time processing applications where DDR timing precision and burst efficiency are mandatory.

FAQ

What is the function of the DOFF pin on CY7C1568KV18-400BZXCT?

The DOFF pin is an active-low PLL disable control. When asserted LOW, it disables the internal PLL and forces the device into DDR I mode with 1-cycle read latency and a maximum operating frequency of 167 MHz. When held HIGH (typically via 10 kΩ pull-up), the device operates in DDR II+ mode at up to 400 MHz with 2.5-cycle latency. This pin enables hardware-selectable performance modes without firmware changes.

How does the QVLD signal improve system timing margin?

QVLD is edge-aligned with the rising edges of the echo clocks CQ and CQ, directly indicating when DQ[17:0] data is valid. This eliminates the need for complex PCB trace length matching or FPGA-based dynamic phase adjustment, as receivers can use QVLD as a ready strobe. In practice, this yields ≥0.45 ns guaranteed data valid window referenced to CQ/CQ - significantly easing timing closure at 400 MHz.

Can CY7C1568KV18-400BZXCT operate with VDDQ = 1.5 V?

Yes. The device supports VDDQ from 1.4 V to VDD (1.8 V), explicitly including 1.5 V operation. This is confirmed in the "DC Electrical Characteristics" section of the datasheet (Document 001-15880 Rev. *R), where parameters like VIH and VIL are specified across the full 1.4–1.8 V range. Using 1.5 V VDDQ is valid for interfacing with 1.5 V FPGA I/O banks while maintaining full timing compliance.

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

ZQ is an impedance calibration reference input. It must be connected to a precision resistor (RQ) tied to ground - typically 240 Ω - to set output driver strength to 0.2 × RQ (e.g., 48 Ω). Alternatively, connecting ZQ directly to VDDQ enables minimum-impedance mode. It must never be left floating or tied to GND, as improper connection causes undefined output drive strength and signal integrity failure.