Cypress Semiconductor Corp CY7C1543KV18-450BZI

Overview

CY7C1543KV18 from Cypress Semiconductor is a 72-Mbit QDR® II+ SRAM with 4M × 18 organization, 450 MHz clock frequency, 2.0-cycle read latency, and separate read/write DDR ports delivering 900 MT/s effective data rate. It operates at 1.8 V core (VDD) and 1.4–1.8 V I/O (VDDQ), housed in a 165-ball FBGA (13 × 15 × 1.4 mm), and targets high-bandwidth packet buffering in network line cards.

For engineers reviewing the CY7C1543KV18 datasheet, CY7C1543KV18 pinout, CY7C1543KV18 application, or CY7C1543KV18 equivalent, key selection criteria include its four-word burst architecture, echo clock (CQ/CQ) timing support, QVLD data validity signaling, HSTL I/O compatibility, and DOFF-configurable 1-cycle vs. 2-cycle latency mode.

Technical Context

The CY7C1543KV18 implements a synchronous pipelined QDR II+ architecture with physically independent read and write data paths-eliminating bus turnaround-and uses rising edges of both K and K clocks for DDR data transfers. Its internal 4M × 18 array is organized as four 1M × 18 banks, accessed via a shared 20-bit address bus latched on alternating K-clock edges.

A built-in PLL enables precise data placement at 450 MHz; when disabled via DOFF = LOW, it reverts to QDR I operation up to 167 MHz with 1-cycle latency. Echo clocks CQ and CQ are free-running, edge-aligned replicas of K/K used for source-synchronous data capture, while QVLD provides cycle-accurate indication of valid output data on Q[17:0].

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 SRAM applications.

Compared with CY7C1543KV18-450BZI, the -400BZI variant trades 100 MHz bandwidth for lower power and cost while maintaining full pin and functional compatibility; the AS7C34098A-15JIN lacks QDR architecture entirely, requiring fundamental redesign of timing, control, and I/O interfaces.

Availability

CY7C1543KV18-450BZI is available at Aetrix Electronics and suitable for network packet buffering, high-speed switch fabric interface, and telecom baseband processing requiring stable component supply, long-term lifecycle assurance, and guaranteed Pb-free compliance.

Supply support for CY7C1543KV18-450BZI 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 applications, with headquarters in San Jose, CA.

This device belongs to Cypress's QDR II+ SRAM product line, engineered specifically for deterministic, high-bandwidth, low-latency memory interfacing in packet-switched infrastructure where concurrent read/write and source-synchronous timing are mandatory.

FAQ

What is the function of the DOFF pin on CY7C1543KV18-450BZI?

The DOFF (Disable PLL) pin is an active-LOW control that disables the internal Phase-Locked Loop. When pulled LOW, the device operates in QDR I mode with 1-cycle read latency and maximum frequency reduced to 167 MHz. When held HIGH (typically via 10 kΩ pull-up), it enables full QDR II+ operation at 450 MHz with 2.0-cycle latency. This pin directly determines the device's timing mode and bandwidth capability.

How does the ZQ pin affect output drive strength?

The ZQ pin connects to an external precision resistor (RQ) tied to ground, enabling on-die calibration of CQ, CQ, and Q[17:0] output driver impedance to match the system data bus. The calibrated output impedance equals 0.2 × RQ. If ZQ is tied directly to VDDQ, the device enters minimum-impedance mode; connecting ZQ to GND or leaving it floating is prohibited and may cause undefined behavior.

Can CY7C1543KV18-450BZI perform simultaneous read and write operations?

Yes - the CY7C1543KV18-450BZI supports true concurrent read and write operations due to its physically separate read and write data ports, independent port selects (RPS/WPS), and shared but multiplexed address bus. Each port operates autonomously: a read burst initiated by RPS can overlap with a write burst initiated by WPS, provided addresses do not conflict within the same bank, eliminating bus turnaround delays.

What is the role of QVLD in system timing design?

QVLD is a synchronous output signal edge-aligned with CQ and CQ that asserts precisely when Q[17:0] data is valid and stable. It replaces reliance on fixed setup/hold timing margins, allowing receivers to latch data only when QVLD is HIGH - essential for robust capture at 450 MHz. Unlike clock-enable schemes, QVLD reflects actual data readiness, accommodating process/voltage/temperature variations without derating.