Infineon Technologies CY7C1645KV18-450BZXI

Overview

CY7C1645KV18 from Cypress Semiconductor is a 4 M × 36, 144-Mbit QDR® II+ SRAM with 450 MHz clock operation, 2.0-cycle read latency, and separate synchronous read/write ports supporting concurrent DDR transfers at 900 Mbps per port. It uses HSTL I/O (VDDQ = 1.4–1.8 V), integrated PLL for precise data placement, and echo clocks (CQ/CQ) for high-speed data capture in networking packet buffers.

For engineers reviewing the CY7C1645KV18 datasheet, CY7C1645KV18 pinout, CY7C1645KV18 application, or CY7C1645KV18 equivalent, key selection criteria include its 4-word burst architecture, DOFF-configurable latency mode (QDR II+ vs QDR I), byte-write select granularity (BWS[3:0]), and 165-ball FBGA package compatibility with high-density routing in telecom line cards and FPGA co-processor memory subsystems.

Technical Context

The CY7C1645KV18 implements a true quad-data-rate II+ architecture with physically isolated read and write data paths-no bus turnaround required. Its 20-bit address bus (A[19:0]) accesses a 4 M × 36 memory array organized as four 1 M × 36 sub-arrays, with addresses latched on alternating edges of K/K clocks.

It integrates a PLL for jitter-tolerant data sampling and provides echo clocks (CQ/CQ) aligned to output data edges, enabling reliable capture at 900 Mbps without external delay tuning. The DOFF pin selects between 2.0-cycle QDR II+ mode (full spec) and 1-cycle QDR I mode (≤167 MHz, PLL disabled).

Key Specifications

Pinout & Package

Package: 165-ball fine-pitch ball grid array (FBGA), 15 mm × 17 mm × 1.4 mm body, RoHS-compliant, with 0.8 mm ball pitch and standard HSTL-compatible pad layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72T36120L10BG and ISSI IS61WV102436B, the CY7C1645KV18 delivers 4.5× higher bandwidth, eliminates bus arbitration overhead via true dual-port architecture, and provides built-in timing aids (PLL, echo clocks, QVLD) essential for deterministic 450 MHz system integration.

Availability

CY7C1645KV18 is available at Aetrix Electronics and suitable for telecom infrastructure, FPGA-accelerated computing, network processor subsystems, and high-speed test equipment requiring stable component supply and long-lifecycle support.

Supply support for CY7C1645KV18 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 embedded and communications applications.

The QDR® II+ SRAM product line targets ultra-low-latency, high-throughput memory subsystems in networking, telecommunications, and FPGA-based acceleration where deterministic timing and concurrent access are critical.

FAQ

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

The DOFF pin disables the internal PLL when pulled low, forcing the device into QDR I mode with 1-cycle read latency and maximum 167 MHz operation. When high, it enables QDR II+ mode with 2.0-cycle latency and full 450 MHz performance. Timing parameters differ significantly between modes-data sheet Tables 10 and 11 specify separate AC characteristics for each configuration.

How does the ZQ pin configure output drive strength?

ZQ connects to an external 50 Ω resistor to ground, allowing the device to calibrate its output drivers to match system trace impedance. This sets CQ, CQ, and Q[35:0] output impedance to 0.2 × RQ (i.e., 10 Ω). Alternatively, tying ZQ to VDDQ enables minimum impedance mode (~7 Ω), but direct grounding or leaving it floating is prohibited and may cause functional failure.

Can CY7C1645KV18 be used with a single-ended clock source?

No. The device requires true differential K/K clock inputs for proper operation. Driving only K while holding K static violates AC timing requirements and causes undefined behavior in address latching, data capture, and PLL lock. A dedicated differential clock generator or transformer is mandatory for compliant operation at 450 MHz.

What is the role of BWS[3:0] during a write operation?

BWS[3:0] are active-low byte write enables that gate corresponding 9-bit segments of D[35:0]: BWS0→D[8:0], BWS1→D[17:9], BWS2→D[26:18], BWS3→D[35:27]. Only bytes with asserted (low) BWS signals are written; unmasked bytes retain prior content, enabling efficient partial-word updates without read-modify-write sequences.