Infineon Technologies CY7C1320CV18-250BZXC

Overview

CY7C1320CV18-250BZXC from Cypress Semiconductor is a 18-Mbit synchronous DDR II SRAM configured as 512K × 36, operating at 250 MHz with 1.8 V core supply and HSTL I/O. It implements 2-word burst addressing, dual-edge echo clocks (CQ/CQ), and on-chip DLL for 1.5-cycle read latency. Used in high-bandwidth networking packet buffers and telecom line-card memory subsystems requiring precise DDR timing and low-latency pipelined access.

For engineers reviewing the CY7C1320CV18-250BZXC datasheet, CY7C1320CV18-250BZXC pinout, CY7C1320CV18-250BZXC application, or CY7C1320CV18-250BZXC equivalent, key selection criteria include DDR II burst architecture, 512K × 36 organization, 250 MHz clock rating, DLL-enabled latency mode, and 165-ball FBGA package compatibility with HSTL-18 signaling.

Technical Context

This device uses a synchronous pipelined SRAM core with DDR II architecture, where address latching occurs on alternate rising edges of K/K clocks and write data is registered on both K and K edges. Read data is driven synchronously on C/C rising edges, with echo clocks CQ/CQ aligned to output timing for simplified capture.

The internal burst counter increments A0 to generate sequential 36-bit word pairs; byte write select inputs BWS[3:0] enable per-byte masking during writes. All synchronous I/O passes through registers clocked by K/K (inputs) or C/C (outputs), and DLL operation enables accurate data placement at 250 MHz with 1.5-cycle read latency.

Key Specifications

Pinout & Package

Package: 165-ball fine-pitch ball grid array (FPBGA), 13 mm × 15 mm × 1.4 mm body height, 0.8 mm ball pitch, RoHS-compliant Pb-free finish (BZXC suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DDR II SRAM applications.

Compared with AS7C331024B-250BIN and IS42S32400F-6BL, CY7C1320CV18-250BZXC delivers superior timing determinism via DLL and echo clocks, enabling reliable 250 MHz operation in multi-device systems without custom delay tuning or voltage headroom trade-offs.

Availability

CY7C1320CV18-250BZXC is available at Aetrix Electronics and suitable for telecom line cards, network packet buffers, baseband processing units, and industrial real-time controllers requiring stable component supply, long-lifecycle support, and guaranteed Pb-free compliance.

Supply support for CY7C1320CV18-250BZXC 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 markets, with emphasis on signal integrity and system-level timing robustness.

CY7C1320CV18 belongs to Cypress's DDR II SRAM product line, engineered specifically for deterministic, low-jitter memory subsystems in high-speed digital signal processing and packet-forwarding applications.

FAQ

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

The DOFF pin disables the internal delay lock loop (DLL) when pulled LOW. In DLL-off mode, the device operates with DDR I timing: 1-cycle read latency and maximum frequency reduced to 167 MHz. This mode retains full functionality but removes DLL-based data-eye centering, making it suitable for thermally constrained environments or legacy controller compatibility where DLL calibration is unavailable.

How does ZQ calibration impact signal integrity on the DQ bus?

ZQ calibration adjusts the output driver impedance of DQ, CQ, and CQ pins to match the system's characteristic impedance (typically 50 Ω). By connecting a 240 Ω resistor from ZQ to ground, the device sets its output strength to 0.2 × RQ = 48 Ω, minimizing reflections and ensuring clean eye diagrams at 534 Mbps per pin. Skipping ZQ calibration risks overshoot, undershoot, and timing closure failure above 200 MHz.

Can CY7C1320CV18-250BZXC operate in single-clock mode, and what are the implications?

Yes - when only K and K are supplied and C/C are left unconnected, the device uses K/K to clock both input sampling and output driving. In this mode, CQ/CQ remain active and synchronized to K/K, preserving echo-clock benefits. However, system-level skew control is less flexible than with independent C/C, limiting maximum achievable data rate to 200 MHz in most layouts due to increased clock-to-out uncertainty.

What is the role of BWS[3:0] during a write operation, and how are byte lanes mapped?

BWS[3:0] are active-low signals that mask individual 9-bit byte lanes during writes: BWS0 controls D[8:0], BWS1 controls D[17:9], BWS2 controls D[26:18], and BWS3 controls D[35:27]. When a BWS bit is HIGH, the corresponding 9-bit segment is ignored and unchanged. This enables true partial writes without read-modify-write cycles, critical for efficient protocol header updates and descriptor table maintenance in networking applications.