Cypress Semiconductor Corp CY7C1268KV18-550BZXC

Overview

CY7C1268KV18-550BZXC from Cypress Semiconductor is a 36-Mbit (2 M × 18) DDR II+ synchronous SRAM with 550 MHz clock operation, 2.5-cycle read latency, and HSTL I/O interface. It delivers 1100 MT/s data throughput via double-data-rate transfers on rising edges of complementary K/K clocks, and integrates echo clocks (CQ/CQ) and QVLD for precise high-speed data capture in networking and packet buffering applications.

For engineers reviewing the CY7C1268KV18-550BZXC datasheet, CY7C1268KV18-550BZXC pinout, CY7C1268KV18-550BZXC application, or CY7C1268KV18-550BZXC equivalent, key selection criteria include DDR II+ burst timing compliance, 1.8 V core / 1.4–1.8 V I/O supply flexibility, JTAG 1149.1 testability, and FBGA-165 package compatibility with high-density memory subsystems.

Technical Context

This SRAM implements a pipelined, synchronous architecture where address and control inputs (LD, R/W, BWS[1:0]) are registered on the rising edge of K only, while write data is latched on both K and K rising edges. Read data is driven synchronously on both K and K edges with 2.5-cycle latency when DOFF = HIGH, enabling deterministic timing alignment across multi-chip depth-expanded systems.

The integrated PLL generates internal timing for accurate data placement; echo clocks CQ/CQ are free-running and phase-aligned to K/K, eliminating board-level skew compensation. ZQ input enables dynamic output impedance tuning to match system trace impedance, and QVLD provides edge-aligned validity indication synchronized to CQ/CQ - critical for reliable DDR latch timing at 550 MHz.

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 0.8 mm ball pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C362000B-550BIN and IS61WV102418BLL-550BLI, CY7C1268KV18-550BZXC uniquely combines full 36-Mbit density, on-die PLL, QVLD, and ZQ in one FBGA-165 package - reducing BOM count and layout complexity for next-gen telecom and test equipment.

Availability

CY7C1268KV18-550BZXC is available at Aetrix Electronics and suitable for high-speed packet buffering, network switch fabric memory, telecom line card buffering, and test equipment pattern memory requiring stable component supply and long-term industrial lifecycle support.

Supply support for CY7C1268KV18-550BZXC 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 communications, industrial, and automotive systems, emphasizing signal integrity and timing predictability.

CY7C1268KV18 belongs to the DDR II+ SRAM product line engineered specifically for deterministic-latency, high-throughput buffering in packet-switched infrastructure - not general-purpose memory.

FAQ

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

The DOFF pin is an active-LOW PLL disable control. When tied HIGH (via 10 kΩ pull-up), the internal PLL operates, enabling 2.5-cycle read latency and full 550 MHz DDR II+ functionality. When pulled LOW, the PLL shuts down and the device reverts to DDR I mode with 1-cycle latency and maximum 167 MHz operation - useful for backward compatibility or power-down states.

How does the ZQ pin calibrate output impedance, and what external component is required?

ZQ connects to an external precision resistor (RQ) tied to ground; the device measures RQ and configures its HSTL output drivers to 0.2 × RQ. For example, a 60 Ω RQ sets DQ/CQ output impedance to 12 Ω. This compensates for voltage/temperature drift and PCB trace variations - no calibration sequence or software command is needed.

Can CY7C1268KV18-550BZXC be depth-expanded, and how is bus contention avoided during transitions?

Yes - multiple devices can be depth-expanded using shared K/K, CQ/CQ, and QVLD signals. Bus contention is prevented because each device automatically tristates its DQ outputs on the next rising edge of K after deselection, allowing seamless handoff between chips without wait states or external bus turn-around logic.

Is the CY7C1268KV18-550BZXC compatible with standard DDR2 or DDR3 memory controllers?

No - it is not compatible with JEDEC DDR2/DDR3 controllers. It requires a dedicated DDR II+ interface with dual-edge clocking, echo clock reception, and QVLD-aware logic. The device implements Cypress's proprietary DDR II+ protocol, not JEDEC-standard DDR, and must be interfaced via ASICs or FPGAs configured for this specific timing and signaling scheme.