Cypress Semiconductor Corp CY7C25652KV18-400BZXI

Overview

CY7C25652KV18 from Cypress Semiconductor is a 72-Mbit QDR® II+ SRAM with 2M × 36 organization, 400 MHz maximum clock frequency, 2.5-cycle read latency, on-die termination (ODT), and HSTL I/O interfaces operating at 1.4 V to 1.8 V. It delivers 1100 MT/s data rate via DDR read/write ports and supports concurrent read/write transactions in high-bandwidth networking packet buffers.

For engineers reviewing the CY7C25652KV18 datasheet, CY7C25652KV18 pinout, CY7C25652KV18 application, or CY7C25652KV18 equivalent, key selection criteria include burst depth (four-word), echo clock (CQ/CQ) timing support, DOFF-configurable latency mode, ODT impedance control via ZQ, and FBGA-165 package compatibility with high-speed PCB routing constraints.

Technical Context

This device implements a synchronous pipelined architecture with physically separate read and write data paths, eliminating bus turnaround delays. It uses dual input clocks (K and K) - both rising-edge triggered - to latch addresses and data, enabling full-duplex operation without arbitration overhead.

The integrated PLL ensures precise data placement relative to echo clocks (CQ/CQ), while the QVLD signal provides edge-aligned validity indication for sampled output data. ODT is configurable per D[35:0], BWS[3:0], and K/K inputs using external ZQ resistor tuning, supporting system-level impedance matching without discrete terminators.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 13 mm × 15 mm × 1.4 mm body height, RoHS-compliant, Pb-free option available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72T36150 and ISSI IS61WV102436B, CY7C25652KV18 uniquely integrates ODT, echo clocks, and QVLD to reduce system-level timing complexity - making it optimal for 400 MHz+ deterministic memory subsystems where PCB area and signal integrity are constrained.

Availability

CY7C25652KV18 is available at Aetrix Electronics and suitable for high-speed network packet buffers, telecom line card memory, baseband processing caches, and test equipment pattern memory requiring stable component supply across extended production lifecycles.

Supply support for CY7C25652KV18 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.

The QDR® II+ SRAM product line targets deterministic, high-bandwidth memory subsystems in networking infrastructure - specifically engineered to replace asynchronous SRAMs and simplify DDR interface design in switch fabric and packet processing ASICs.

FAQ

What is the function of the DOFF pin on CY7C25652KV18?

The DOFF (Delay OFF) pin configures read latency mode: when asserted HIGH, it enables 2.5-cycle latency for QDR II+ operation; when LOW, it reverts to 1-cycle latency compatible with legacy QDR I timing. This pin is sampled during initialization and remains static during normal operation - it does not support dynamic switching between modes.

How does the ZQ pin calibrate output impedance?

The ZQ pin connects to an external precision resistor (typically 240 Ω) to ground, allowing the device to measure reference current and adjust internal output driver strength to match 50 Ω transmission lines. Output impedance is set to 0.2 × RQ, so a 240 Ω ZQ resistor yields 48 Ω drive strength - ensuring minimal reflection on high-speed data buses.

Can CY7C25652KV18 operate with only one clock input?

No - the device requires both K and K clock inputs. Although both are rising-edge triggered, they serve distinct roles: K controls read-port timing (address latching and Q[35:0] output), while K controls write-port timing (address latching and D[35:0] sampling). Using only one clock violates timing specifications and prevents concurrent operation.

What happens to Q[35:0] outputs when RPS is deasserted?

When RPS is deasserted (HIGH), the read port is deselected and Q[35:0] outputs enter high-impedance (tri-state) mode on the next rising edge of the K clock. This behavior is synchronous and automatic - no additional control signals or delay circuits are needed to manage bus contention during port switching.