Cypress Semiconductor Corp CY7C1270KV18-400BZXI

Overview

CY7C1270KV18-400BZXI from Cypress Semiconductor is a 36-Mbit (1 M × 36) DDR II+ synchronous pipelined SRAM with 2.5-cycle read latency, 400 MHz clock operation, HSTL I/O interface, and 165-ball FBGA (13 × 15 × 1.4 mm) package. It delivers 800 MB/s peak bandwidth via double-data-rate transfers at 800 Mbps per data pin, supports programmable impedance matching via ZQ, and integrates echo clocks (CQ/CQ) and QVLD for precise high-speed data capture in memory subsystems used in network packet buffers and baseband processing.

For engineers reviewing the CY7C1270KV18-400BZXI datasheet, CY7C1270KV18-400BZXI pinout, CY7C1270KV18-400BZXI application, or CY7C1270KV18-400BZXI equivalent, key selection criteria include its 2.5-cycle vs. 1-cycle latency mode (controlled by DOFF), dual-clock (K/K) timing architecture, 1.8 V core / 1.4–1.8 V I/O supply flexibility, JTAG 1149.1 test access, and synchronous self-timed write capability.

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 and K clocks. All synchronous inputs (A, R/W, LD, BWS[3:0]) are registered on the rising edge of K; write data is latched on both K and K edges, while read data is driven synchronously on both clock edges with echo-clock alignment.

The integrated PLL enables accurate data placement for 2.5-cycle latency operation when DOFF is HIGH; disabling the PLL (DOFF LOW) reverts behavior to DDR I mode with 1-cycle latency and ≤167 MHz max frequency. QVLD provides edge-aligned valid-data indication synchronized to CQ/CQ, eliminating system-level strobe skew compensation.

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, 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 AS7C33600B-400BIN and IS61WV102436BLL-400BLI, CY7C1270KV18-400BZXI uniquely combines HSTL I/O, echo clocks + QVLD, ZQ calibration, DOFF-configurable latency, and JTAG - enabling simpler board layout, higher signal integrity, and broader deployment flexibility across test, telecom, and industrial domains.

Availability

CY7C1270KV18-400BZXI is available at Aetrix Electronics and suitable for network packet buffering, baseband signal processing, and test equipment data acquisition requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for CY7C1270KV18-400BZXI 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 system-level integration.

CY7C1270KV18 belongs to the QDR II+/DDR II+ SRAM product line, engineered specifically for high-bandwidth, low-latency memory subsystems in packet-switched infrastructure and real-time digital signal processing platforms.

FAQ

What is the function of the DOFF pin on CY7C1270KV18-400BZXI?

The DOFF (PLL Disable) pin is an active-LOW control that toggles the device between DDR II+ and DDR I operational modes. When pulled HIGH (via 10 kΩ pull-up), the internal PLL enables 2.5-cycle read latency at up to 400 MHz. When tied LOW, the PLL is disabled, reverting timing to 1-cycle latency with a maximum frequency of 167 MHz - matching legacy DDR I specifications for backward compatibility.

How does the ZQ pin affect signal integrity in high-speed designs?

The ZQ pin connects to an external 240 Ω resistor to ground, enabling on-die calibration of DQ, CQ, and CQ output driver impedance to precisely 48 Ω (0.2 × 240 Ω). This dynamic tuning compensates for process, voltage, and temperature variations, maintaining consistent signal rise/fall times and reducing reflections on high-speed parallel buses operating at 800 Mbps.

Can CY7C1270KV18-400BZXI be used in depth-expanded memory configurations?

Yes - the device supports seamless depth expansion using LD (load) and R/W (read/write) signals. When multiple devices share address and clock lines, asserting LD LOW on one device while others are deselected allows independent burst access without external wait-state insertion. Output tristating occurs automatically after the final K edge of a read, enabling clean bus handoff between chips.

Is JTAG boundary-scan supported, and what standard does it comply with?

Yes - CY7C1270KV18-400BZXI integrates a fully compliant IEEE 1149.1 (JTAG) test access port with TDI, TDO, TCK, TMS, and TRST pins. It supports instruction register loading, boundary scan register access, and identification register readout, enabling PCB interconnect testing, in-system programming verification, and manufacturing fault detection without functional memory access.