Infineon Technologies CY7C1550KV18-450BZXI

Overview

CY7C1550KV18-450BZXI from Cypress Semiconductor is a 72-Mbit (2M × 36) synchronous pipelined DDR II+ SRAM with 450 MHz clock frequency, 2.0-cycle read latency, and dual-edge DDR data transfer at 900 Mbps. It features echo clocks (CQ/CQ), QVLD data-valid indicator, and programmable impedance matching via ZQ pin. Used in high-bandwidth networking line cards and packet buffering systems requiring deterministic low-latency burst access.

For engineers reviewing the CY7C1550KV18-450BZXI datasheet, CY7C1550KV18-450BZXI pinout, CY7C1550KV18-450BZXI application, or CY7C1550KV18-450BZXI equivalent, key selection criteria include DDR II+ timing compliance, 2M × 36 depth/width configuration, 1.8 V core / 1.4–1.8 V I/O supply support, and FBGA-165 package compatibility with high-speed PCB layout constraints.

Technical Context

The device implements a two-word burst architecture synchronized to complementary K/K clocks, where address latching occurs on alternating rising edges and data is registered on both edges. Internal PLL enables precise data placement for 2.0-cycle latency mode when DOFF is HIGH; disabling the PLL via DOFF LOW reverts operation to DDR I mode with 1-cycle latency up to 167 MHz.

All synchronous inputs (A, R/W, LD, BWS[3:0]) are registered on K's rising edge; write data is sampled on both K and K edges; read data is driven on both edges with tight alignment to echo clocks CQ/CQ. QVLD provides edge-aligned indication of valid output data, eliminating need for external strobes in high-speed capture.

Key Specifications

Pinout & Package

Package: 165-ball fine-pitch ball grid array (FBGA), 13 mm × 15 mm × 1.4 mm body, RoHS-compliant, Pb-free option available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72T3652L10BG and IS61WV102436BLL-15BLI, CY7C1550KV18-450BZXI delivers double the density and 2.7× higher effective bandwidth with built-in timing aids (QVLD, CQ/CQ), reducing FPGA logic overhead and PCB routing complexity in 10G+ systems.

Availability

CY7C1550KV18-450BZXI is available at Aetrix Electronics and suitable for network packet buffering, telecom line card cache, FPGA-based protocol acceleration, and high-speed test equipment requiring stable component supply and long-term industrial availability.

Supply support for CY7C1550KV18-450BZXI 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 fabless semiconductor company specializing in high-performance memory, microcontrollers, and connectivity solutions for industrial, automotive, and communications markets.

CY7C1550KV18 belongs to Cypress's QDR II+/DDR II+ SRAM product line, engineered specifically for deterministic, low-jitter, high-bandwidth buffering in packet-switched infrastructure where timing predictability outweighs cost-per-bit optimization.

FAQ

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

The DOFF pin is an active-low PLL disable control. When asserted HIGH, the internal PLL enables DDR II+ mode with 2.0-cycle read latency at up to 450 MHz. When pulled LOW, the PLL is disabled and the device operates in DDR I mode with 1-cycle latency but limited to ≤167 MHz. This allows hardware-selectable performance vs. compatibility trade-offs without firmware changes.

How do CQ and CQ echo clocks simplify system timing?

CQ and CQ are free-running output clocks synchronized to K and K, respectively, and edge-aligned with DQ data transitions. They eliminate the need for system-level delay tuning or phase-locked capture logic, allowing receivers (e.g., FPGA input registers) to sample DQ using CQ/CQ as local clocks - reducing timing margin uncertainty to ≤0.45 ns.

Can CY7C1550KV18-450BZXI operate with VDDQ = 1.5 V while VDD = 1.8 V?

Yes. The device supports independent VDDQ from 1.4 V to VDD (1.8 V), so 1.5 V VDDQ is fully compliant. This enables direct interfacing with 1.5 V HSTL-15 FPGA I/O banks while maintaining 1.8 V core logic stability, avoiding level shifters and associated signal integrity penalties.

What is the role 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; output drivers (DQ, CQ, CQ) then self-tune to 0.2 × RQ. Alternatively, ZQ may be tied directly to VDDQ to enable minimum-impedance mode. It must never be left floating or connected to GND - doing so disables calibration and degrades signal integrity.