Cypress Semiconductor Corp CY7C1425KV18-250BZI

Overview

CY7C1425KV18 from Cypress Semiconductor is a 4M × 9 (36-Mbit), 1.8 V QDR® II SRAM with independent read/write ports, 333 MHz clock operation (666 MHz DDR data rate), 1.5-cycle read latency (DOFF = HIGH), and 165-ball FBGA (13 × 15 × 1.4 mm) packaging. It delivers concurrent burst transfers of two 9-bit words per access for high-bandwidth networking buffer applications.

For engineers reviewing the CY7C1425KV18 datasheet, CY7C1425KV18 pinout, CY7C1425KV18 application, or CY7C1425KV18 equivalent, key selection criteria include dual-clock DDR timing support (K/K and C/C), echo clocks (CQ/CQ) for source-synchronous capture, HSTL-compatible I/O (VDDQ = 1.4–1.8 V), JTAG 1149.1 testability, and programmable impedance calibration via ZQ pin.

Technical Context

This QDR II SRAM implements fully pipelined, synchronous architecture with physically separate read and write data paths-eliminating bus turnaround delays. It uses rising edges only of K/K for address/data capture and C/C for output registration, enabling deterministic 1.5-cycle read latency when DOFF is asserted HIGH.

The device integrates a PLL for precise internal timing alignment, supports depth expansion via RPS/WPS and byte-write selects (BWS0), and provides full data coherency through on-chip self-timed write circuitry. Echo clocks CQ/CQ are free-running and phase-aligned to C/C, simplifying high-speed PCB layout and receiver timing closure.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 13 mm × 15 mm × 1.4 mm body, 0.8 mm ball pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72T3615L10PA and IS61WV102418BLL-15BLI, the CY7C1425KV18 uniquely supports 333 MHz operation with echo clocks and ZQ calibration-making it the only choice for 666 MT/s deterministic buffering in carrier-grade infrastructure.

Availability

CY7C1425KV18 is available at Aetrix Electronics and suitable for network packet buffering, high-speed switch fabric memory, and telecom line card buffering requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for CY7C1425KV18 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.

The QDR II SRAM product line targets high-bandwidth, low-latency buffering in networking and test equipment-emphasizing deterministic timing, concurrent access, and signal integrity at multi-Gbps rates.

FAQ

What is the function of the DOFF pin on CY7C1425KV18?

The DOFF (Data Output OFF) pin configures read latency mode: when asserted HIGH, it enables 1.5-cycle latency for improved timing margin in high-frequency systems; when LOW, it reverts to 1-cycle latency like QDR I. This setting is sampled synchronously on the rising edge of K and remains active until changed.

How does the ZQ pin enable impedance calibration?

The ZQ pin connects to an external 240 Ω resistor to ground, allowing the device to calibrate its HSTL output drivers' pull-up/pull-down strengths. This compensation maintains consistent signal rise/fall times and termination matching across voltage, temperature, and process variations-critical for reliable 666 MT/s operation.

Can CY7C1425KV18 operate with only one clock domain?

Yes. When C and C are tied together and driven by K (or K), the device operates in single-clock mode. In this configuration, Q[8:0] is registered on K/K edges, and CQ/CQ are generated relative to K. All timing parameters shift accordingly, and echo-clock benefits are forfeited.

What is the purpose of BWS0 in CY7C1425KV18?

BWS0 (Byte Write Select 0) is an active-LOW signal that gates write enable for the entire D[8:0] bus. When deasserted, incoming data on D[8:0] is ignored-preserving existing memory contents. It enables partial-word writes without requiring read-modify-write sequences, reducing controller overhead in burst-oriented protocols.