Infineon Technologies CY7C1321KV18-250BZXC

Overview

CY7C1321KV18-250BZXC from Cypress Semiconductor is a 18-Mbit synchronous pipelined DDR II SRAM configured as 512K × 36, operating at 250 MHz with 1.8 V core supply and HSTL I/O. It supports four-word burst reads/writes, dual-edge echo clocks (CQ/CQ), and programmable output impedance via ZQ pin. Used in high-bandwidth networking buffers and packet-switching ASIC interfaces where deterministic latency and precise data capture are critical.

For engineers reviewing the CY7C1321KV18-250BZXC datasheet, CY7C1321KV18-250BZXC pinout, CY7C1321KV18-250BZXC application, or CY7C1321KV18-250BZXC equivalent, this page delivers verified timing behavior, burst address mapping, DOFF-controlled read latency modes (1-cycle vs. 1.5-cycle), and FBGA-165 package interface details essential for DDR II memory subsystem design.

Technical Context

The device implements a synchronous pipelined architecture with internal two-bit burst counter driven by A[1:0], delivering four sequential 36-bit words per access. All synchronous inputs (R/W, LD, BWS[3:0], A[18:0]) are registered on rising edges of K/K clocks; all outputs (DQ[35:0], CQ/CQ) are edge-aligned to C/C or K/K in single-clock mode.

It integrates a PLL for accurate data placement, JTAG 1149.1 test access port, and variable-drive HSTL output buffers supporting 1.4 V–VDD output swing. Read latency is configurable: 1 cycle when DOFF = LOW (DDR I mode), 1.5 cycles when DOFF = HIGH (DDR II mode), with self-timed writes and echo-clock–assisted data capture eliminating board-level skew compensation.

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 (BZXC suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C331024B-25TIN and IS61WV102432BLL-15BLI, CY7C1321KV18-250BZXC delivers 2.5× higher effective bandwidth via DDR and eliminates board-level timing closure challenges through integrated echo clocks and programmable drive strength.

Availability

CY7C1321KV18-250BZXC is available at Aetrix Electronics and suitable for telecom line card buffers, high-speed packet switch ASIC interfaces, medical imaging data pipelines, and test equipment waveform memory requiring stable component supply and long-term industrial availability.

Supply support for CY7C1321KV18-250BZXC 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) is a fabless semiconductor company specializing in high-performance memory, microcontrollers, and connectivity solutions for industrial, automotive, and communications markets.

CY7C1321KV18 belongs to Cypress's DDR II SRAM product line, engineered specifically for deterministic, high-bandwidth data buffering in networking, test, and medical imaging systems demanding sub-cycle timing control and signal integrity at 250+ MHz.

FAQ

What is the function of the DOFF pin on CY7C1321KV18-250BZXC?

The DOFF (Data Output OFF) pin configures read latency mode: when asserted HIGH, it enables DDR II operation with 1.5-cycle read latency; when LOW, it reverts to DDR I mode with 1-cycle latency. This setting directly affects the timing relationship between LD assertion and first valid DQ output, and must be held stable during power-up and operation.

Can CY7C1321KV18-250BZXC operate without external C and C clocks?

Yes - the device supports single-clock mode where K and K serve as both input and output clocks. In this configuration, C and C pins are unused, CQ/CQ are generated relative to K/K, and timing margins tighten due to lack of deskew capability. Full DDR II performance requires C/C for optimal system-level timing closure.

How does ZQ pin calibration affect signal integrity?

ZQ connects to an external resistor (typically 240 Ω) to ground, enabling on-die calibration of DQ and CQ output driver strength to match PCB trace impedance. This reduces reflection-induced overshoot/undershoot and ensures consistent eye height across voltage and temperature, critical for reliable 250 MHz DDR operation without external termination.

Is CY7C1321KV18-250BZXC pin-compatible with CY7C1319KV18-250BZXC?

No - although both use the same 165-ball FBGA package, pin assignments differ significantly: CY7C1319KV18 has DQ[17:0] and BWS[1:0], while CY7C1321KV18 uses DQ[35:0] and BWS[3:0]. Address bus width (A[19:0] vs. A[18:0]), and byte-select mapping are incompatible; PCB layout and controller firmware must be redesigned for migration.