Infineon Technologies CY7C1321CV18-167BZC

Overview

CY7C1321CV18 from Cypress Semiconductor is a 18-Mbit synchronous pipelined DDR-II SRAM configured as 512K × 36, operating at up to 300 MHz with 600 Mbps DDR data transfer rate, 1.5-cycle read latency (DLL enabled), and HSTL I/O compatible with 1.8V core supply - deployed in high-bandwidth packet buffering for telecom line cards and network switches.

For engineers reviewing the CY7C1321CV18 datasheet, CY7C1321CV18 pinout, CY7C1321CV18 application, or CY7C1321CV18 equivalent, key selection criteria include burst depth (4-word), byte write select support (BWS[3:0]), echo clock timing (CQ/CQ), DLL-controlled latency mode, and FBGA-165 package compatibility with high-speed PCB layout constraints.

Technical Context

This SRAM implements a synchronous pipelined architecture with dual-clock DDR interface: K/K clocks latch addresses and write data on alternating rising edges, while C/C clocks drive read data with echo clocks CQ/CQ aligned to output timing. Burst counter uses A[1:0] to sequence four 36-bit words per access.

The device supports two operational modes: DLL-enabled DDR-II mode (1.5-cycle read latency, up to 300 MHz) and DLL-disabled DDR-I mode (1-cycle latency, max 167 MHz). Write operations use on-chip self-timed control, and impedance matching is managed via ZQ pin referenced to external resistor.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 13 mm × 15 mm footprint, 1.4 mm height, 0.8 mm ball pitch, JEDEC MO-245 compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1319CV18, CY7C1321CV18 delivers double the effective bandwidth per device via 36-bit bus width and maintains tighter timing control through DLL and echo clocks; versus IS61WV102436BLL-15BLI, it trades QDR concurrency for lower latency DDR burst access and integrated impedance calibration.

Availability

CY7C1321CV18 is available at Aetrix Electronics and suitable for telecom infrastructure, high-speed switch fabric, network processor co-processing, and ATE pattern memory applications requiring stable component supply and long-term industrial availability.

Supply support for CY7C1321CV18 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 networking, automotive, and industrial systems, with emphasis on signal integrity and timing precision.

CY7C1321CV18 belongs to Cypress's DDR-II synchronous SRAM product line, engineered specifically for deterministic-latency, high-throughput buffering in packet-switched infrastructure where burst efficiency and clock deskew are critical.

FAQ

What is the minimum supported clock frequency for CY7C1321CV18?

The device has no specified minimum clock frequency. It operates down to DC in DLL-enabled mode, and functional operation is guaranteed across the full industrial temperature range (–40°C to +85°C) at any frequency up to 300 MHz. Timing parameters scale linearly with clock period, allowing flexible low-frequency use in power-sensitive applications.

How does the ZQ pin affect signal integrity in a multi-SRAM system?

ZQ calibrates output driver impedance to match the system data bus characteristic impedance (typically 50 Ω). With a 250 Ω resistor to ground, outputs are tuned to 50 Ω (0.2 × 250 Ω), minimizing reflections and ensuring clean eye diagrams across all 36 DQ lines - especially critical when multiple CY7C1321CV18 devices share a common bus.

Can CY7C1321CV18 operate without connecting C and C clocks?

Yes. When C and C are unconnected or tied to VDDQ/VSS, the device defaults to single-clock mode using K and K for both input sampling and output driving. In this mode, CQ and CQ become copies of K and K, and timing reverts to DDR-I specifications with 1-cycle latency - verified up to 167 MHz per the selection guide.

What happens to BWS[3:0] during a read operation?

BWS[3:0] are ignored during read operations. These inputs are sampled only on rising edges of K/K during write cycles and have no effect on read data output, address decoding, or burst sequencing. They remain don't-care inputs during read transactions and may be left unconnected or held static.