Cypress Semiconductor Corp CY7C25682KV18-550BZXC

Overview

CY7C25682KV18-550BZXC from Cypress Semiconductor is a 72-Mbit (4M × 18) synchronous pipelined DDR II+ SRAM with two-word burst architecture, 2.5-cycle read latency at 550 MHz, on-die termination (ODT), and HSTL I/O. It operates with core VDD = 1.8 V ± 0.1 V and supports 1.4–1.8 V I/O supply. Used in high-bandwidth networking and telecom line cards where precise DDR timing and echo-clock–assisted data capture are required.

For engineers reviewing the CY7C25682KV18-550BZXC datasheet, CY7C25682KV18-550BZXC pinout, CY7C25682KV18-550BZXC application, or CY7C25682KV18-550BZXC equivalent, key selection criteria include 550 MHz clock frequency, dual-edge DDR interface with CQ/CQ echo clocks, QVLD data-valid signaling, ODT support for D/BWS/K/K inputs, and FBGA-165 package compatibility with depth-expansion topologies.

Technical Context

This device implements a synchronous pipelined SRAM core with DDR II+ peripheral logic, using rising edges of complementary K/K clocks to latch addresses and control signals, and both edges to register write data and drive read data. Its internal organization comprises two 2M × 18 arrays enabling concurrent access management.

The PLL ensures accurate data placement relative to echo clocks CQ/CQ, while QVLD provides edge-aligned indication of valid output data. DOFF pin selects between 2.5-cycle latency (DOFF = HIGH) and 1-cycle DDR I–mode latency (DOFF = LOW), allowing runtime mode switching without reconfiguration.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C3256B-15JCIN and IS61WV102418BLL-10BLI, CY7C25682KV18-550BZXC delivers 9× higher bandwidth and integrated signal integrity features (ODT, CQ, QVLD), making it uniquely suited for next-generation packet-processing hardware where timing precision and density are critical.

Availability

CY7C25682KV18-550BZXC is available at Aetrix Electronics and suitable for high-speed packet buffering, telecom line card memory, depth-expanded memory subsystems, and network processor co-processor caches requiring stable component supply across extended production lifecycles.

Supply support for CY7C25682KV18-550BZXC 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-critical systems.

CY7C25682KV18 belongs to the QDR II+ SRAM product line, engineered specifically for bandwidth-constrained, low-latency applications in packet-switched infrastructure where DDR timing predictability and echo-clock–assisted capture are essential.

FAQ

What is the function of the DOFF pin on CY7C25682KV18-550BZXC?

The DOFF (DDR Off) pin configures read latency mode: when asserted HIGH, the device operates in DDR II+ mode with 2.5-cycle read latency; when LOW, it behaves as a DDR I device with 1-cycle latency. This pin is sampled at power-up and latched, enabling runtime mode selection without reinitialization. Its state directly determines burst timing behavior and must be stable before the first valid K clock edge.

How does On-Die Termination (ODT) work on this SRAM?

ODT on CY7C25682KV18-550BZXC applies calibrated termination resistors to D[17:0], BWS[1:0], K, and K inputs using an external ZQ resistor (175–350 Ω). The ODT pin selects termination range: LOW selects RQ/3.33 (~53–105 Ω), HIGH selects RQ/1.66 (~105–212 Ω). This eliminates discrete termination components, reduces stub length, and improves signal integrity at 550 MHz without layout compromises.

Can CY7C25682KV18-550BZXC be used in depth-expanded configurations?

Yes-its automatic output tri-state on deselect, identical timing across devices, and echo-clock synchronization make it ideal for depth expansion. When one device completes a read, its outputs tri-state on the next K edge, allowing another device on the same DQ bus to drive data without contention. No additional control logic or wait states are needed, supporting scalable memory width growth up to 4M × 36 or beyond.

What is the role of CQ and CQ pins in system timing?

CQ and CQ are free-running echo clocks synchronized to K and K, respectively. They provide a timing reference that tracks DQ[17:0] output skew, enabling the memory controller to sample data using CQ/CQ instead of K/K-reducing timing uncertainty caused by PCB trace mismatches. QVLD further indicates exact valid data windows, allowing safe capture even under voltage/temperature variation.