Infineon Technologies CY7C1543V18-375BZC

Overview

CY7C1543V18 from Cypress Semiconductor is a 4M × 18-bit (72-Mbit), 1.8V QDR-II+ SRAM with separate read/write ports, 375 MHz clock operation, 2.0-cycle read latency, and DDR interfaces delivering 750 MT/s effective data rate. It implements synchronous pipelined burst architecture for high-bandwidth networking buffer applications requiring concurrent access and full data coherency.

For engineers reviewing the CY7C1543V18 datasheet, CY7C1543V18 pinout, CY7C1543V18 application, or CY7C1543V18 equivalent, key selection criteria include its 165-ball FBGA package, HSTL I/O compatibility, DLL-enabled precise timing alignment, echo clocks (CQ/CQ) for source-synchronous capture, and QVLD signaling for reliable data valid indication in high-speed systems.

Technical Context

The CY7C1543V18 uses a dual-clock DDR architecture with independent K and K inputs driving separate input/output registers; all synchronous signals are edge-aligned to rising edges only. Its internal 1M × 18 memory array is organized across four sub-arrays, accessed via 20-bit multiplexed address bus latched on alternating K edges.

It integrates a Delay Lock Loop (DLL) for zero-skew output timing, supports depth expansion via RPS/WPS controls, and provides byte-level write masking through BWS[1:0] pins. The device operates with core VDD = 1.8V ± 0.1V and IO VDDQ = 1.4V to 1.8V, using HSTL Class I inputs and variable-drive HSTL outputs.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 15 mm × 17 mm × 1.4 mm, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72T3615L10BG and IS61WV102418B, the CY7C1543V18 delivers 4.5× higher effective bandwidth (750 vs. 166 MT/s), eliminates external timing compensation via integrated DLL/echo clocks, and supports true concurrent access-making it uniquely suited for modern packet-processing and real-time signal acquisition systems.

Availability

CY7C1543V18 is available at Aetrix Electronics and suitable for network switch buffers, high-speed ATE memory subsystems, telecom baseband datapaths, and real-time video processing requiring stable component supply and long-term lifecycle support.

Supply support for CY7C1543V18 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 headquarters in San Jose, CA.

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

FAQ

What is the function of the DOFF pin on CY7C1543V18?

The DOFF pin disables the internal Delay Lock Loop when pulled LOW. In this state, the device reverts to QDR-I timing mode with maximum clock frequency reduced to 167 MHz. This mode is used for debug, timing margin analysis, or fallback operation when DLL calibration fails. Normal operation requires DOFF tied HIGH via ≤10 kΩ pull-up.

How does the ZQ pin affect output drive strength?

The ZQ pin connects to an external 240Ω resistor to ground to calibrate the output driver impedance of Q[17:0] and CQ/CQ pins to 48Ω (0.2 × RQ). This matches standard PCB trace impedances, minimizing reflections and ensuring clean signal edges at 750 MT/s. Leaving ZQ unconnected or tying it to GND violates specification and causes undefined output behavior.

Can CY7C1543V18 operate with only the K clock, ignoring K?

No. Both K and K clocks are required: K drives address, RPS, WPS, and BWS inputs, while both K and K sample D[17:0] and drive Q[17:0]. The device does not support single-clock operation. Omitting K will prevent write data capture and read data output, causing functional failure regardless of K presence.

What is the purpose of the BWS[1:0] pins in CY7C1543V18?

BWS[1:0] are active-LOW byte write select signals that enable partial-word writes to the 18-bit data bus. BWS0 controls D[8:0] (lower 9 bits), and BWS1 controls D[17:9] (upper 9 bits). When either is deasserted, the corresponding 9-bit segment is ignored during write, preserving existing memory contents - eliminating need for read-modify-write sequences in protocol header updates.