Cypress Semiconductor Corp CY7C1245KV18-400BZXI

Overview

CY7C1245KV18-400BZXI from Cypress Semiconductor is a 36-Mbit QDR® II+ SRAM with 1M × 36 organization, 2.0-cycle read latency, 400 MHz clock frequency, DDR interfaces on independent read/write ports, and HSTL I/O supporting 1.4–1.8 V VDDQ. It delivers 2.88 Gbps bandwidth in high-speed networking line cards requiring deterministic burst memory access.

For engineers reviewing the CY7C1245KV18-400BZXI datasheet, CY7C1245KV18-400BZXI pinout, CY7C1245KV18-400BZXI application, or CY7C1245KV18-400BZXI equivalent, key selection factors include its 400 MHz operation with 2-cycle latency, separate RPS/WPS control, echo clocks (CQ/CQ) for timing margin, QVLD data validity signaling, and 165-ball FBGA package compatibility with high-density PCB layouts.

Technical Context

The CY7C1245KV18-400BZXI implements a true dual-port synchronous architecture with physically isolated read and write data paths-no bus turnaround required. Its four-word burst transfers 144 bits per read cycle (36-bit × 4), synchronized to both K and K rising edges, achieving full-duplex 900 MT/s effective data rate at 400 MHz clock.

An internal PLL aligns output timing to input clocks, enabling precise data capture via echo clocks CQ and CQ. The DOFF pin selects between QDR II+ mode (2-cycle latency, up to 450 MHz) and QDR I mode (1-cycle latency, ≤167 MHz), while ZQ enables programmable output impedance matching to system trace impedance.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar QDR II+ SRAM applications.

Compared with IDT72T3615L10BG and IS61WV102436B, CY7C1245KV18-400BZXI uniquely supports runtime latency mode switching (via DOFF), higher 400 MHz operation, and integrated PLL-based echo clock generation-making it optimal for next-generation high-throughput, low-jitter memory subsystems.

Availability

CY7C1245KV18-400BZXI is available at Aetrix Electronics and suitable for network packet buffering, telecom line card memory, baseband processing cache, and test equipment pattern memory requiring stable component supply across multi-year production cycles.

Supply support for CY7C1245KV18-400BZXI 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 demanding communications and industrial applications.

CY7C1245KV18 belongs to the QDR® II+ SRAM product line, engineered specifically for deterministic, high-bandwidth memory access in packet-switched infrastructure where bus turnaround latency and timing margin are critical constraints.

FAQ

What is the function of the DOFF pin on CY7C1245KV18-400BZXI?

The DOFF (PLL Disable) pin controls the device's operational mode: when asserted LOW, it disables the internal PLL and forces QDR I timing with 1-cycle read latency and maximum 167 MHz clock rate; when HIGH, the device operates in QDR II+ mode with 2-cycle latency and up to 450 MHz. This provides hardware-selectable latency/bandwidth trade-offs without firmware changes.

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

The ZQ pin enables on-die output impedance calibration: connecting it to a precision resistor to ground sets CQ, CQ, and Q[35:0] driver impedance to 0.2×RQ, matching typical 50 Ω PCB traces. This reduces reflections and improves eye diagram margins at 900 MT/s-eliminating need for external series termination resistors and saving board space.

Can CY7C1245KV18-400BZXI perform simultaneous read and write to the same address?

No. While the device supports concurrent read and write operations to *different* addresses due to independent ports, writing to an address currently being read from results in undefined data on the read port during that burst. The architecture guarantees coherency only for non-overlapping accesses; overlapping address conflicts must be managed by system-level arbitration logic.

What is the role of QVLD in system timing validation?

QVLD is an edge-aligned output that pulses high exactly when Q[35:0] carries valid data from the current four-word burst. Unlike relying on clock edges alone, QVLD provides unambiguous, jitter-immune indication of data validity-enabling robust capture in FPGA-based controllers without tight static timing closure on Q[35:0] paths.