Cypress Semiconductor Corp CY7C1520KV18-333BZXC

Overview

CY7C1520KV18-333BZXC from Cypress Semiconductor is a 72-Mbit (2M × 36) synchronous DDR-II SRAM with two-word burst architecture, 333 MHz clock operation, double-data-rate interface delivering 666 MT/s effective bandwidth, and HSTL I/O compatible with 1.5 V or 1.8 V VDDQ. It operates with 1-cycle read latency in DDR-I mode (DOFF = LOW) or 1.5-cycle latency in DDR-II mode (DOFF = HIGH), targeting high-speed packet buffering in networking line cards.

For engineers reviewing the CY7C1520KV18-333BZXC datasheet, CY7C1520KV18-333BZXC pinout, CY7C1520KV18-333BZXC application, or CY7C1520KV18-333BZXC equivalent, key selection criteria include burst depth (2-word), dual-clock timing (K/K and C/C), echo clocks (CQ/CQ), programmable output drive via ZQ calibration, and 165-ball FBGA (13 × 15 × 1.4 mm) package compatibility with high-density PCB layouts.

Technical Context

This SRAM implements a synchronous pipelined architecture with internal burst counter driven by A0, supporting linear address incrementing across two 1M × 36 arrays. All synchronous inputs-including R/W, LD, BWS[3:0], and DQ[35:0]-are registered on rising edges of K and K clocks, enabling precise setup/hold timing control.

Read data is edge-aligned to C and C clocks (or K/K in single-clock mode), with echo clocks CQ/CQ phase-matched to output data for simplified capture at the controller. The integrated PLL ensures accurate data placement, while ZQ input enables dynamic output impedance tuning to match system trace impedance (0.2 × RQ).

Key Specifications

Pinout & Package

Package: 165-ball FBGA (13 × 15 × 1.4 mm), ball pitch 0.8 mm, JEDEC MO-270AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C3256A-15JCIN and IS61WV102432BLL-10BLI, CY7C1520KV18-333BZXC delivers 3.3× higher effective bandwidth, eliminates address bus toggling via burst mode, and provides calibrated I/O for 666 MT/s signal integrity-critical for next-generation packet processing.

Availability

CY7C1520KV18-333BZXC is available at Aetrix Electronics and suitable for telecom line cards, high-speed switch fabric buffers, and network processor offload memory requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for CY7C1520KV18-333BZXC 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, with emphasis on signal integrity and timing precision.

CY7C1520KV18 belongs to Cypress's DDR-II SRAM product line, engineered specifically for deterministic, low-latency buffering in multi-gigabit serial data paths where burst efficiency and clock deskew are critical.

FAQ

What is the function of the DOFF pin on CY7C1520KV18-333BZXC?

The DOFF (DDR Off) pin configures read latency mode: when asserted LOW, the device operates in DDR-I mode with 1-cycle read latency; when HIGH, it enables DDR-II mode with 1.5-cycle latency. This setting affects internal timing of read data launch relative to C/C clocks and must be stable before initialization. DOFF is sampled synchronously on the rising edge of K during power-up or reset.

Can CY7C1520KV18-333BZXC operate without external C and C clocks?

Yes - the device supports single-clock mode using only K and K for both input latching and output timing. In this configuration, read data and echo clocks (CQ/CQ) are aligned to K/K instead of C/C. However, system-level timing margin is reduced due to lack of independent output clock deskewing, and maximum operating frequency may be limited by combined clock path skew.

How does ZQ calibration affect signal integrity in high-speed designs?

ZQ calibration adjusts the output driver strength of DQ[35:0], CQ, and CQ pins to match the characteristic impedance of the PCB trace (typically 50 Ω). By connecting a precision 50 Ω resistor from ZQ to GND, the device achieves 0.2 × RQ = 10 Ω on-die termination, reducing reflections and improving eye diagram opening at 666 MT/s. Leaving ZQ unconnected or tied to GND violates specification and causes undefined drive strength.

What is the role of BWS[3:0] during a write operation?

BWS[3:0] are active-low byte write select signals that gate individual 9-bit lanes of the 36-bit DQ bus during writes. BWS0 controls D[8:0], BWS1 controls D[17:9], BWS2 controls D[26:18], and BWS3 controls D[35:27]. Only bytes with corresponding BWS asserted LOW are written; others retain prior contents. All BWS signals are sampled synchronously on the rising edge of K/K along with write data.