Cypress Semiconductor Corp CY7C1543KV18-450BZC

Overview

CY7C1543KV18 from Cypress Semiconductor is a 4M × 18-bit (72-Mbit), 450 MHz QDR® II+ SRAM with separate read/write ports, 2.0-cycle read latency, DDR interfaces on both ports (900 Mbps effective data rate), and HSTL I/O supporting 1.4–1.8 V VDDQ. It serves as high-bandwidth buffer memory in network packet processors requiring concurrent burst reads and writes without bus turnaround.

For engineers reviewing the CY7C1543KV18 datasheet, CY7C1543KV18 pinout, CY7C1543KV18 application, or CY7C1543KV18 equivalent, key selection criteria include its 4-word burst architecture, DOFF-configurable latency mode (QDR I vs. QDR II+), echo clock timing support for 450 MHz operation, and 165-ball FBGA package compatibility with high-speed PCB layout constraints.

Technical Context

This SRAM implements true dual-port synchronous pipelined architecture: independent K and K clocks drive separate read and write pipelines, with address latching on alternating rising edges. The internal PLL enables precise 2.0-cycle read latency alignment and supports echo clocks (CQ/CQ) for source-synchronous data capture at 900 MHz.

It uses multiplexed address inputs (A[19:0]), byte-write select inputs (BWS[1:0]), and port-select signals (RPS/WPS) to enable depth expansion and partial writes. Core logic operates at 1.8 V ±0.1 V, while I/O buffers are configurable between 1.5 V and 1.8 V via VDDQ, with VREF-biased HSTL input receivers and variable-drive HSTL outputs.

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, 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 IDT72T3615L10BG and IS61WV102418BLL-10BLI, CY7C1543KV18 delivers 4.5× higher effective bandwidth via DDR + 4-word burst, supports deterministic 2-cycle latency for real-time systems, and provides echo-clock timing essential for >400 MHz operation - features absent in both alternatives.

Availability

CY7C1543KV18 is available at Aetrix Electronics and suitable for network packet buffering, high-speed test equipment memory, telecom line card buffering, and multi-core processor cache coherency applications requiring stable component supply and long-term industrial availability.

Supply support for CY7C1543KV18 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.

CY7C1543KV18 belongs to the QDR® II+ SRAM product line, engineered specifically for full-duplex, high-throughput memory subsystems in packet-switched infrastructure where deterministic latency and concurrent access are mandatory.

FAQ

What is the function of the DOFF pin on CY7C1543KV18?

The DOFF pin controls the internal PLL: when pulled HIGH (via 10 kΩ pull-up), the device operates in QDR II+ mode with 2.0-cycle read latency and full 450 MHz capability; when pulled LOW, the PLL is disabled and the device reverts to QDR I timing with 1-cycle latency and reduced maximum frequency (≤167 MHz). This allows runtime mode switching without changing clock sources.

How does the ZQ pin affect signal integrity?

The ZQ pin connects to an external 240 Ω resistor to ground, enabling on-die calibration of CQ, CQ, and Q[17:0] output driver impedance to match the system's 48 Ω data bus. This calibration reduces reflection-induced jitter and ensures consistent eye opening across voltage/temperature variations-critical for reliable 900 Mbps DDR signaling.

Can CY7C1543KV18 be used with a single-ended clock source?

No. The device requires differential clock inputs (K and K) for proper operation: K drives read-port logic and address latching, while K drives write-port logic and write-data sampling. Both clocks must be supplied with matched trace lengths and controlled slew rates; using only one clock violates timing specifications and prevents valid burst operation.

What is the purpose of BWS[1:0] in this 18-bit configuration?

BWS[1:0] enables selective writing of 9-bit subwords: BWS0 controls D[8:0], BWS1 controls D[17:9]. When either signal is deasserted, its corresponding 9-bit segment remains unaltered during the 4-word burst write. This allows efficient partial updates (e.g., modifying header fields without overwriting payload) and reduces unnecessary memory writes in protocol processing engines.