Cypress Semiconductor Corp CY7C15632KV18-400BZXI

Overview

CY7C15632KV18-400BZXI from Cypress Semiconductor is a 72-Mbit QDR® II+ SRAM with four-word burst architecture, 2.5-cycle read latency, and dual DDR interfaces operating at 400 MHz (800 MT/s per port). It features separate read/write ports, echo clocks (CQ/CQ), QVLD data-valid indicator, and 165-ball FBGA (13 × 15 × 1.4 mm) packaging. Used in high-throughput packet buffering for network switches and routers.

For engineers reviewing the CY7C15632KV18-400BZXI datasheet, CY7C15632KV18-400BZXI pinout, CY7C15632KV18-400BZXI application, or CY7C15632KV18-400BZXI equivalent, key selection criteria include 4 M × 18 organization, DOFF-configurable latency (2.5-cycle vs. 1-cycle), HSTL I/O compatibility, PLL-based timing alignment, and depth expansion via RPS/WPS controls.

Technical Context

The device implements synchronous pipelined burst access with independent read and write ports sharing a multiplexed 20-bit address bus. Each port uses DDR signaling on K/K clocks, enabling 800 MT/s data transfer per port at 400 MHz input clock frequency. Internal organization is four 1 M × 18 arrays, supporting full data coherency across concurrent transactions.

Latency mode is selected by DOFF: HIGH enables QDR II+ mode (2.5-cycle read latency); LOW forces QDR I mode (1-cycle latency, ≤167 MHz operation). Echo clocks CQ/CQ are free-running, edge-aligned to K/K for simplified high-speed capture, while QVLD provides cycle-accurate output validity indication synchronized to CQ/CQ edges.

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 Pb-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72T3615L10BG and IS61WV102418BLL-10BLI, CY7C15632KV18-400BZXI delivers 4× higher density and 80× greater effective bandwidth via DDR + burst, but requires careful PLL lock and echo-clock routing-making it optimal for new high-speed designs, not drop-in replacements.

Availability

CY7C15632KV18-400BZXI is available at Aetrix Electronics and suitable for high-speed network switching, telecom line card buffering, and PCIe accelerator memory requiring stable component supply and long-term industrial availability.

Supply support for CY7C15632KV18-400BZXI 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 emphasis on signal integrity and timing precision.

This device belongs to the QDR® II+ SRAM product line, engineered specifically for deterministic, low-latency, full-duplex memory access in packet-processing and real-time signal-path systems.

FAQ

What is the function of the DOFF pin, and how does it affect timing?

The DOFF pin selects between QDR II+ (DOFF = HIGH) and QDR I (DOFF = LOW) operational modes. In QDR II+ mode, the device achieves 2.5-cycle read latency at up to 500 MHz; in QDR I mode, latency drops to 1 cycle but maximum frequency is limited to 167 MHz. The PLL is disabled in QDR I mode, altering setup/hold timing margins and eliminating echo clock functionality.

How do CQ and CQ echo clocks improve system timing margin?

CQ and CQ are free-running output clocks synchronized to K and K, respectively, with fixed phase alignment. They provide a local, jitter-reduced timing reference for external latches capturing Q[17:0], eliminating the need for board-level delay tuning or fly-by routing. This reduces skew between data and capture clock, improving setup/hold margins at 400 MHz operation.

Can BWS0 and BWS1 be used to perform partial writes without reading existing data?

Yes. BWS0 controls D[8:0] and BWS1 controls D[17:9]; asserting either LOW enables writing only the corresponding 9-bit byte group while leaving unselected bytes unchanged. This is a true write-mask operation executed entirely within the SRAM's self-timed write circuitry-no read-modify-write sequence is required, preserving bandwidth and determinism.

What is the role of the ZQ pin, and how must it be connected?

ZQ calibrates output driver impedance for CQ, CQ, and Q[17:0] to match the system data bus. It must be connected to a precision resistor (RQ) tied to ground; output impedance is set to 0.2 × RQ. Alternatively, tying ZQ to VDDQ enables minimum-impedance mode. ZQ must never be left floating or connected to GND, as this disables calibration and risks signal integrity failure.