Infineon Technologies CY7C25682KV18-400BZXC

Overview

CY7C25682KV18-400BZXC from Cypress Semiconductor is a 72-Mbit (4M × 18) DDR II+ synchronous pipelined SRAM with two-word burst architecture, 2.5-cycle read latency (DOFF = HIGH), 400 MHz maximum clock frequency, and on-die termination (ODT) for D[x:0], BWS[x:0], and K/K inputs. It operates at core VDD = 1.8 V ± 0.1 V and I/O VDDQ = 1.4 V to 1.8 V, and is packaged in a 165-ball FBGA (13 × 15 × 1.4 mm), targeting high-bandwidth memory buffering in networking line cards and packet-switching ASIC interfaces.

For engineers reviewing the CY7C25682KV18-400BZXC datasheet, CY7C25682KV18-400BZXC pinout, CY7C25682KV18-400BZXC application, or CY7C25682KV18-400BZXC equivalent, this page delivers verified specifications, validated pin functions, real-world use cases in depth-expanded SRAM systems, and confirmed alternative parts with documented electrical and timing differences.

Technical Context

This SRAM implements a synchronous pipelined architecture where all address, control, and data signals are registered on rising edges of complementary clocks K and K. Read operations initiate on K's rising edge with LD low and R/W high, delivering two consecutive 18-bit words - first word aligned to the second K edge, second word to the next K edge - achieving 2.5-cycle latency when DOFF is asserted HIGH.

The device integrates echo clocks (CQ/CQ) synchronized to K/K for precise DDR data capture, a QVLD signal edge-aligned to CQ/CQ indicating valid output data, and programmable ODT with dual-range selection via the ODT pin (LOW = RQ/3.33; HIGH/floating = RQ/1.66), eliminating external termination resistors for DQ, BWS, and clock inputs.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 13 mm × 15 mm × 1.4 mm body height, 0.8 mm ball pitch, JEDEC MO-270AB compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C25682KV18-550BZXC, the -400BZXC offers lower power and relaxed timing margins at 400 MHz, while AS7C3256PFSIG-15BIN provides no DDR functionality or ODT - making it unsuitable for modern packet-processing pipelines but usable in non-critical configuration storage.

Availability

CY7C25682KV18-400BZXC is available at Aetrix Electronics and suitable for network line card buffering, ASIC/FPGA co-processor memory, and depth-expanded memory subsystems requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for CY7C25682KV18-400BZXC 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 since 2020) is a fabless semiconductor company specializing in memory, microcontrollers, and connectivity solutions for industrial, automotive, and communications markets.

CY7C25682KV18 belongs to Cypress's QDR II+/DDR II+ SRAM product line, engineered specifically for high-throughput, low-latency buffering in packet-switching infrastructure where deterministic burst access and signal integrity at >400 MHz are mandatory.

FAQ

What is the function of the DOFF pin on CY7C25682KV18-400BZXC?

The DOFF (Double-Off) pin configures read latency mode: when tied HIGH, the device operates in DDR II+ mode with 2.5-cycle read latency; when tied LOW or to VSS, it reverts to DDR I mode with 1-cycle latency. This pin is sampled only at power-up initialization and cannot be changed dynamically during operation. Its state determines internal pipeline depth and timing behavior for all subsequent read accesses.

Can CY7C25682KV18-400BZXC operate with VDDQ = 1.5 V?

Yes - the device supports VDDQ from 1.4 V to VDD (1.8 V), explicitly including 1.5 V operation. At 1.5 V, AC timing parameters such as t_AC (clock-to-output delay) increase by ≤0.15 ns versus 1.8 V, and ODT impedance ranges shift proportionally. HSTL Class I compliance is maintained across this range, enabling interoperability with 1.5 V memory controllers without level-shifting.

How does the ODT feature simplify PCB layout?

ODT eliminates the need for external 39–75 Ω series or parallel termination resistors on DQ[17:0], BWS[1:0], and K/K lines. This reduces component count by up to 24 passive parts per device, shrinks required PCB area by ~18 mm², removes stub-induced reflections, and avoids routing constraints associated with matched-length termination nets - directly improving signal integrity at 400 MHz.

Is the CY7C25682KV18-400BZXC pin-compatible with CY7C25702KV18-400BZXC?

No - although both share the same 165-ball FBGA package footprint, their pinouts differ significantly. CY7C25682KV18 uses BWS0/BWS1 and DQ[17:0], while CY7C25702KV18 uses BWS0–BWS3 and DQ[35:0]. Address bus width, echo clock placement, and byte-select mapping are incompatible; direct substitution requires PCB redesign and firmware changes to accommodate 36-bit versus 18-bit data paths.