Cypress Semiconductor Corp CY7C1568KV18-400BZXI

Overview

CY7C1568KV18 from Cypress Semiconductor is a 72-Mbit (4M × 18) synchronous pipelined DDR II+ SRAM with two-word burst architecture, 2.5-cycle read latency at 550 MHz, HSTL I/O interface, and 1.8 V core / 1.4–1.8 V I/O supply. It delivers 1100 MT/s data throughput via double-data-rate transfers synchronized to K/K clocks and is used in high-bandwidth networking line cards and packet buffer subsystems.

For engineers reviewing the CY7C1568KV18 datasheet, CY7C1568KV18 pinout, CY7C1568KV18 application, or CY7C1568KV18 equivalent, key selection criteria include DDR II+ timing compliance, echo clock (CQ/CQ) alignment for source-synchronous capture, QVLD validity signaling, DOFF-configurable 1- vs 2.5-cycle latency mode, and 165-ball FBGA mechanical compatibility.

Technical Context

This SRAM implements a synchronous, pipelined architecture where all address, control, and data signals are registered on rising edges of complementary K/K clocks. Internal organization comprises two 2M × 18 arrays, enabling two sequential 18-bit words per access. Read data is driven on both K and K edges with precise placement governed by an integrated PLL.

The device supports dual operational modes: DDR II+ mode (DOFF = HIGH) with 2.5-cycle latency and 550 MHz max frequency, and DDR I mode (DOFF = LOW) with 1-cycle latency up to 167 MHz. Echo clocks CQ/CQ are free-running, phase-aligned replicas of K/K, eliminating system-level skew compensation.

Key Specifications

Pinout & Package

Available in a 165-ball fine-pitch ball grid array (FBGA) package measuring 13 mm × 15 mm × 1.4 mm, with 0.8 mm ball pitch and Pb-free option. Pin assignments follow JEDEC MO-245AC standard layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72T3615 and IS61WV102418B, CY7C1568KV18 uniquely combines DDR II+ burst efficiency, echo-clock–assisted timing closure, and programmable latency-making it irreplaceable in high-speed packet buffering where sub-nanosecond data validity alignment is required.

Availability

CY7C1568KV18 is available at Aetrix Electronics and suitable for high-bandwidth networking line cards, telecom infrastructure equipment, and test instrumentation requiring stable component supply and long-term lifecycle support.

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) is a U.S.-based semiconductor company specializing in high-performance memory, microcontrollers, and connectivity solutions for industrial, automotive, and communications markets.

The CY7C1568KV18 belongs to Cypress's DDR II+ SRAM product line, engineered specifically for deterministic, low-latency, high-throughput buffering in packet-switched networks and real-time signal processing systems.

FAQ

What is the function of the DOFF pin on CY7C1568KV18?

The DOFF (PLL Turn Off) pin is an active-LOW control that disables the internal PLL. When asserted LOW, the device reverts to DDR I timing with 1-cycle read latency and maximum 167 MHz operation. When HIGH, it enables full DDR II+ mode with 2.5-cycle latency and 550 MHz capability. Pull-up to VDDQ via ≤10 kΩ resistor is required for normal operation.

How does the ZQ pin affect output drive strength?

The ZQ pin connects to an external resistor to ground (typically 240 Ω) to calibrate the output impedance of DQ[17:0], CQ, and CQ pins to 0.2 × RQ (≈48 Ω). This matches standard 50 Ω PCB trace impedance, minimizing reflections and ensuring signal integrity at 550 MHz. Connecting ZQ directly to VDDQ enables minimum-impedance mode; floating or grounding ZQ is prohibited.

Can CY7C1568KV18 operate with only one clock input?

No. The device requires both complementary K and K clock inputs. All synchronous operations-including address latching, data capture, and output driving-depend on both edges. K captures address and control signals; both K and K register write data and drive read data. Omitting either clock violates timing specifications and prevents functional operation.

What is the purpose of the QVLD signal in system design?

QVLD (Valid Output Indicator) is an edge-aligned strobe that asserts precisely when DQ[17:0] carries valid burst data-synchronized to CQ/CQ transitions. It eliminates reliance on fixed setup/hold windows, allowing receivers to latch data only during confirmed valid periods. This is critical in systems with variable trace delays or multi-drop DDR buses where static timing margins are insufficient.