Cypress Semiconductor Corp CY7C1270XV18-633BZXC

Overview

CY7C1270XV18-633BZXC from Infineon Technologies (formerly Cypress) is a 36-Mbit synchronous pipelined DDR II+ Xtreme SRAM configured as 1 M × 36, operating at 633 MHz with 2.5-cycle read latency, HSTL I/O, and dual echo clocks (CQ/CQ) for precise high-speed data capture in memory subsystems. It delivers 1266 MT/s effective bandwidth and supports 1.4–1.6 V I/O supply with 1.8 V core.

For engineers reviewing the CY7C1270XV18-633BZXC datasheet, CY7C1270XV18-633BZXC pinout, CY7C1270XV18-633BZXC application, or CY7C1270XV18-633BZXC equivalent, key selection criteria include DDR II+ burst timing, DOFF-controlled PLL mode switching (2.5-cycle vs. 1-cycle latency), QVLD-synchronized output validation, and 165-ball FBGA package compatibility with high-density memory interfaces.

Technical Context

This SRAM implements a two-word burst architecture where each address access retrieves two consecutive 36-bit words on alternating edges of K/K clocks. Internal pipelining and synchronous self-timed writes eliminate external write strobes, while echo clocks CQ/CQ are phase-aligned to K for deterministic data capture without board-level skew compensation.

The device integrates a JTAG 1149.1 test access port and programmable impedance tuning via ZQ pin, enabling system-level termination matching. Its PLL enables precise 2.5-cycle latency operation; asserting DOFF LOW disables the PLL and reverts timing to DDR I mode (1-cycle latency, ≤167 MHz), providing backward compatibility in legacy systems.

Key Specifications

Pinout & Package

Package: 165-ball fine-pitch ball grid array (FBGA), 13 mm × 15 mm × 1.4 mm, Pb-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1270XV18-633BZXC, CY7C1271XV18-633BZXC adds diagnostic capability without sacrificing performance, while AS7C362000B-633BIN trades DDR II+ flexibility for simplified interface-making the original optimal for systems needing configurable latency and source-synchronous timing.

Availability

CY7C1270XV18-633BZXC is available at Aetrix Electronics and suitable for high-speed network packet buffers, test equipment pattern memory, avionics data acquisition systems, and medical imaging frame stores requiring stable component supply and long-term industrial lifecycle support.

Supply support for CY7C1270XV18-633BZXC 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

Infineon Technologies acquired Cypress Semiconductor in 2020 and maintains full product continuity, documentation, and manufacturing for the former Cypress SRAM portfolio including DDR II+ Xtreme devices.

This part belongs to the DDR II+ Xtreme SRAM product line, engineered specifically for deterministic, low-latency burst memory applications in networking, test instrumentation, and real-time embedded systems demanding >1 GHz effective bandwidth.

FAQ

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

The DOFF pin is an active-low PLL disable input. When asserted HIGH, the internal PLL enables DDR II+ mode with 2.5-cycle read latency and 633 MHz operation. When pulled LOW, the PLL is disabled and the device operates in DDR I mode with 1-cycle latency and maximum 167 MHz clock rate. This hardware-selectable mode allows one SRAM design to serve both high-performance and legacy-compatible systems without controller firmware changes.

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

CQ and CQ are free-running output clocks synchronized to the K input clock and edge-aligned with DQ[35:0] data transitions. They provide a local, source-synchronous timing reference at the receiver, eliminating the need for board-level trace length matching between clock and data lines. This reduces timing uncertainty caused by skew and jitter, enabling reliable 1266 MT/s operation without complex receiver deskew circuitry.

Can CY7C1270XV18-633BZXC be used in depth-expanded configurations?

Yes. The device supports depth expansion using LD and R/W signals to coordinate multi-chip access. Its synchronous burst architecture and shared K/K clocking allow stacking multiple CY7C1270XV18-633BZXC units to increase total memory depth while maintaining two-word burst behavior across the bank. No external address decoding logic is required beyond standard LD assertion sequencing.

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

ZQ is an impedance calibration input that sets output driver strength for DQ, CQ, and CQ pins. It must be connected to a precision resistor (RQ) tied to ground; output impedance becomes 0.2 × RQ. For example, a 60 Ω resistor yields 12 Ω driver impedance. Direct connection to VDDQ enables minimum impedance mode. ZQ must never be left floating or tied to GND, as this disables calibration and risks signal integrity failure.