Infineon Technologies CY7C1648KV18-400BZXC

Overview

CY7C1648KV18-400BZXC from Cypress Semiconductor is a 144-Mbit QDR® II SRAM with 8 M × 18 organization, 333 MHz clock frequency, 1.8 V core supply (VDD), and 1.4–1.8 V I/O supply (VDDQ), packaged in a 165-ball FBGA (15 × 17 × 1.4 mm). It implements separate read/write ports, four-word burst architecture, and DDR interfaces on both ports for concurrent high-bandwidth memory access in network packet buffers.

For engineers reviewing the CY7C1648KV18-400BZXC datasheet, CY7C1648KV18-400BZXC pinout, CY7C1648KV18-400BZXC application, or CY7C1648KV18-400BZXC equivalent, this device supports precise timing-critical designs requiring zero bus turnaround, echo-clock–assisted data capture, and depth expansion via independent port selects in telecom line cards and FPGA co-processor caches.

Technical Context

The CY7C1648KV18-400BZXC employs QDR II architecture with fully independent synchronous read and write ports, each using DDR signaling-enabling 666 MT/s effective data rate at 333 MHz K/K clock. It uses dual input clocks (K/K) for address/data capture and dual output clocks (C/C) with echo clocks (CQ/CQ) to deskew flight time mismatches across high-speed PCB traces.

It features a 1.5-cycle read latency when DOFF = HIGH (QDR II mode) or 1-cycle latency when DOFF = LOW (QDR I compatibility mode), and supports byte-write masking via BWS[1:0] for selective 9-bit sub-word updates without read-modify-write cycles. Internal self-timed writes ensure deterministic write completion timing.

Key Specifications

Pinout & Package

Package: 165-ball fine-pitch ball grid array (FBGA), 15 mm × 17 mm × 1.4 mm body, 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 IDT72T3615L10PA and IS61QW25636A-300BQ, CY7C1648KV18-400BZXC uniquely supports 333 MHz operation, 18-bit ×8M configuration, programmable ZQ impedance, and selectable 1/1.5-cycle read latency - making it optimal for bandwidth-constrained, mixed-voltage telecom and FPGA-attached buffer applications.

Availability

CY7C1648KV18-400BZXC is available at Aetrix Electronics and suitable for network packet buffers, FPGA co-processor caches, telecom line card buffers, and high-speed test equipment requiring stable component supply, long-lifecycle assurance, and consistent FBGA packaging.

Supply support for CY7C1648KV18-400BZXC 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.

CY7C1648KV18-400BZXC belongs to Cypress's QDR II SRAM product line, engineered specifically for ultra-low-latency, concurrent-access memory subsystems in networking infrastructure and high-end test instrumentation where deterministic timing and bus efficiency are critical.

FAQ

What is the function of the DOFF pin on CY7C1648KV18-400BZXC?

The DOFF (Data Output OFFset) pin configures read latency mode: when asserted HIGH, it enables QDR II mode with 1.5-cycle read latency; when LOW, it reverts to QDR I compatibility mode with 1-cycle latency. This setting is sampled synchronously on the rising edge of K and remains latched until next power-up or reset. It does not affect write timing or burst structure.

Can CY7C1648KV18-400BZXC operate with only a single clock domain?

Yes - the device supports single-clock mode where K and C are tied together (and K and C tied together), allowing simplified timing with one pair of differential clocks. In this mode, Q[17:0] is clocked by K/K instead of C/C, and CQ/CQ are generated relative to K/K. All timing parameters shift accordingly, and read latency remains configurable via DOFF.

How is output impedance calibrated using the ZQ pin?

ZQ connects to an external precision resistor (typically 240 Ω) between ZQ and ground, enabling on-die calibration of Q[17:0] and CQ/CQ driver impedance to 0.2 × RQ (≈48 Ω). This matches standard PCB trace impedances and minimizes reflections. Connecting ZQ directly to VDDQ enables minimum-impedance (strongest drive) mode; floating or grounding ZQ is prohibited and may cause malfunction.

Is CY7C1648KV18-400BZXC pin-compatible with other Cypress QDR II SRAMs?

No - CY7C1648KV18-400BZXC is not pin-compatible with CY7C1613KV18 or CY7C1615KV18 despite sharing the same FBGA package footprint. Pin assignments differ significantly (e.g., BWS[1:0] placement, CQ/CQ location, and VREF routing), and the 165-ball mapping is unique to this variant. Board-level reuse requires full schematic and layout revision.