Cypress Semiconductor Corp CY7C1265KV18-550BZC

Overview

CY7C1265KV18 from Cypress Semiconductor is a 1M × 36, 36-Mbit QDR® II+ SRAM with 2.5-cycle read latency, 550 MHz clock operation (1100 MT/s DDR), 1.8 V core supply, and 1.4–1.8 V I/O supply. It features separate read/write ports, echo clocks (CQ/CQ), QVLD data-valid indicator, and JTAG 1149.1 test access-designed for high-bandwidth packet buffering in network switches and routers.

For engineers reviewing the CY7C1265KV18 datasheet, CY7C1265KV18 pinout, CY7C1265KV18 application, or CY7C1265KV18 equivalent, key selection criteria include burst depth (four 36-bit words), HSTL I/O compatibility, PLL-controlled timing accuracy, and FBGA-165 package thermal/mechanical constraints for dense PCB layouts.

Technical Context

The CY7C1265KV18 implements a synchronous, pipelined QDR II+ architecture with independent read and write ports sharing a multiplexed 18-bit address bus. All inputs are registered on rising edges of K (positive) and K (negative) clocks, enabling true concurrent read/write transactions without bus turnaround.

It uses an internal PLL to align echo clocks (CQ/CQ) with input clocks for precise DDR data capture, and supports programmable output impedance via ZQ pin. DOFF pin selects between 2.5-cycle QDR II+ mode (DOFF = HIGH) and 1-cycle QDR I mode (DOFF = LOW), with corresponding frequency limits (550 MHz vs. 167 MHz).

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.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C336518B-550BIN and IS42S32800J-5BL, the CY7C1265KV18 uniquely delivers deterministic 2.5-cycle latency, true concurrent access, and hardware-assisted timing (CQ/QVLD/ZQ) essential for deterministic high-speed packet and sample buffering.

Availability

CY7C1265KV18 is available at Aetrix Electronics and suitable for network switching, telecom line cards, high-speed test instrumentation, and broadcast video processing requiring stable component supply across extended product lifecycles.

Supply support for CY7C1265KV18 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) is a fabless semiconductor company specializing in high-performance memory, microcontrollers, and connectivity solutions for industrial, automotive, and communications markets.

The CY7C1265KV18 belongs to Cypress's QDR® II+ SRAM product line, engineered specifically for deterministic, low-latency, high-throughput buffering in infrastructure equipment where bus turnaround overhead and timing uncertainty must be eliminated.

FAQ

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

The DOFF pin disables the internal PLL when driven LOW, reverting the CY7C1265KV18 to QDR I mode with 1-cycle read latency and maximum 167 MHz operation. When HIGH, the PLL enables 2.5-cycle latency and full 550 MHz performance. This dual-mode capability allows backward compatibility with legacy QDR I designs while supporting next-generation bandwidth demands.

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

CQ and CQ are free-running, phase-aligned copies of K and K clocks, respectively, routed alongside Q[35:0] outputs. They provide a local, low-skew reference for capturing DDR data at the receiver, eliminating clock-to-data skew caused by PCB trace length mismatches. This directly improves setup/hold timing margins at 1100 MT/s, especially in multi-drop or long-trace configurations.

Can the CY7C1265KV18 be used with 1.5 V VDDQ only?

Yes. The device supports VDDQ from 1.4 V to 1.8 V, including 1.5 V nominal. At 1.5 V, it meets all AC/DC specifications for HSTL Class I and III interfaces, and maintains full 550 MHz operation. No configuration change is required-only ensure VDDQ supply stability within ±3% and proper decoupling per the datasheet layout guidelines.

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

ZQ enables output driver impedance calibration. It must be connected to a precision resistor (typically 240 Ω) tied to ground, setting output impedance to 48 Ω (0.2 × 240 Ω). Alternatively, connecting ZQ directly to VDDQ enables minimum-impedance mode (~24 Ω). ZQ must never be left floating or tied to ground, as this disables calibration and risks signal integrity failure at high speeds.