Cypress Semiconductor Corp CY7C1520KV18-333BZI

Overview

CY7C1520KV18-333BZI from Cypress Semiconductor is a 72-Mbit synchronous DDR-II SRAM configured as 2M × 36, operating at 333 MHz with double-data-rate (666 MHz effective) I/O, 1.8 V core supply, HSTL-compatible interfaces, and echo clocks (CQ/CQ) for precise high-speed data capture in networking and telecom buffer applications.

For engineers reviewing the CY7C1520KV18-333BZI datasheet, CY7C1520KV18-333BZI pinout, CY7C1520KV18-333BZI application, or CY7C1520KV18-333BZI equivalent, key selection factors include burst-mode latency control via DOFF, dual-clock domain timing (K/K and C/C), programmable output impedance via ZQ, and JTAG 1149.1 test support for system-level validation.

Technical Context

The device implements a two-word synchronous burst architecture: address A0 drives an internal 1-bit burst counter that sequentially accesses two 36-bit words per transaction. All synchronous inputs (R/W, LD, BWS[3:0], A[20:0]) are registered on rising edges of K and K clocks, enabling precise setup/hold timing control.

Read data is driven on rising edges of C and C clocks (or K/K in single-clock mode), synchronized to echo clocks CQ/CQ referenced to C/C - eliminating board-level skew compensation. The integrated PLL ensures accurate data placement relative to output clocks, and self-timed write circuitry guarantees deterministic write completion independent of external timing margins.

Key Specifications

Pinout & Package

Package: 165-ball fine-pitch ball grid array (FBGA), 13 mm × 15 mm × 1.4 mm, RoHS-compliant, Pb-free option available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS61VPS51236A-333BQI and MT47H64M16HR-37E:H, CY7C1520KV18-333BZI provides guaranteed 1-cycle read latency, integrated echo clocks for simplified capture, and ZQ impedance tuning - making it uniquely suited for deterministic, high-speed packet buffering where timing predictability outweighs raw density.

Availability

CY7C1520KV18-333BZI is available at Aetrix Electronics and suitable for 10G Ethernet switch buffers, OTN transport line cards, LTE baseband processing, and broadcast video encoding requiring stable component supply, long-lifecycle support, and consistent parametric performance across temperature and voltage.

Supply support for CY7C1520KV18-333BZI 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 timing precision.

CY7C1520KV18 belongs to Cypress's DDR-II Burst SRAM product line, engineered specifically for deterministic, low-latency buffering in high-speed serial data infrastructure where echo-clock synchronization and programmable latency are mandatory.

FAQ

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

The DOFF (Data Output OFFset) pin configures read latency mode: when asserted HIGH, it enables DDR-II operation with 1.5-cycle read latency for improved jitter tolerance; when LOW, it selects DDR-I mode with 1-cycle latency for minimum access delay. This setting is sampled synchronously on the K clock and remains latched until power-on reset or mode change.

How does ZQ calibration work on CY7C1520KV18-333BZI?

ZQ calibration adjusts the output driver strength of DQ[35:0] and CQ/CQ pins to match the system's data bus impedance. A precision resistor (RQ) is connected between ZQ and ground; the device measures RQ and sets output impedance to 0.2 × RQ. If ZQ is tied to VDDQ, minimum impedance mode activates - no external resistor required, but less precise matching.

Can CY7C1520KV18-333BZI operate in single-clock mode?

Yes. When C and C are not driven, the device uses K and K as both input and output clocks. In this mode, read data is driven on K/K rising edges, and CQ/CQ are generated relative to K/K instead of C/C. All timing parameters shift accordingly, and maximum frequency may be reduced due to combined clock path constraints.

What is the purpose of the BWS[3:0] signals?

BWS[3:0] (Byte Write Select) are active-low signals that enable selective writing of 9-bit byte lanes within the 36-bit DQ bus. BWS0 controls DQ[8:0], BWS1 controls DQ[17:9], BWS2 controls DQ[26:18], and BWS3 controls DQ[35:27]. Unselected bytes retain their prior values, supporting partial-word updates without read-modify-write cycles.