Cypress Semiconductor Corp CY7C1643KV18-450BZI

Overview

CY7C1643KV18 from Cypress Semiconductor is a 144-Mbit QDR® II+ SRAM with 8 M × 18 organization, 450 MHz clock frequency, 2.0-cycle read latency, and separate read/write DDR ports delivering 900 MT/s effective data rate. It operates at 1.8 V core (VDD) and 1.4–1.8 V I/O (VDDQ), housed in a 165-ball FBGA (15 × 17 × 1.4 mm), and targets high-bandwidth packet buffering in network line cards.

For engineers reviewing the CY7C1643KV18 datasheet, CY7C1643KV18 pinout, CY7C1643KV18 application, or CY7C1643KV18 equivalent, this device supports concurrent read/write transactions, echo-clock–assisted timing capture, byte-selectable writes, JTAG boundary scan, and PLL-controlled data placement for deterministic high-speed memory interfacing.

Technical Context

The CY7C1643KV18 implements a true dual-port synchronous architecture with physically independent read and write data paths-no bus turnaround required. Its four-word burst transfers 72 bits per access (4 × 18-bit words), latched on alternating rising edges of K and K clocks to sustain full bandwidth at 450 MHz.

It integrates an internal PLL for precise output data alignment, uses echo clocks (CQ/CQ) synchronized to input clocks for receiver timing margin, and supports programmable output impedance via ZQ calibration. The DOFF pin enables runtime switching between QDR II+ (2-cycle latency) and legacy QDR I (1-cycle latency, ≤167 MHz) modes.

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.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72T3615L10BG and IS61WV102418BLL-15BLI, the CY7C1643KV18 uniquely delivers 450 MHz QDR II+ performance in ×18 configuration with integrated ZQ calibration and echo clocks-making it optimal for new designs requiring deterministic high-speed burst access without external timing compensation.

Availability

CY7C1643KV18 is available at Aetrix Electronics and suitable for network line cards, high-speed test instrumentation, and telecom baseband modules requiring stable component supply, long-lifecycle availability, and guaranteed Pb-free compliance.

Supply support for CY7C1643KV18 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.

The QDR® II+ SRAM product line was designed specifically for deterministic, low-latency, high-bandwidth memory interfacing in packet-processing and signal-processing systems-prioritizing timing predictability over density or cost.

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, reverting the device to QDR I mode with 1-cycle read latency and maximum clock frequency of 167 MHz. In normal operation (DOFF high), the PLL enables 2-cycle latency at 450 MHz with precise data placement. Timing parameters differ significantly between modes-designers must select one mode and use its corresponding AC specifications.

How does the ZQ pin calibrate output impedance, and what external component is required?

ZQ connects to a precision resistor (RQ) tied to ground; the device measures RQ and adjusts driver strength so that CQ, CQ, and Q[17:0] output impedances equal 0.2 × RQ. A typical 40 Ω resistor yields ~8 Ω drive strength. Direct connection to VDDQ enables minimum impedance mode; floating or grounding ZQ is prohibited and may cause undefined behavior.

Can CY7C1643KV18 perform simultaneous read and write to the same address location?

No-while read and write ports operate concurrently, the device ensures data coherency by internally synchronizing access to shared memory cells. A write to an address being read returns the pre-write value during that burst; the updated value appears on subsequent reads. This behavior is guaranteed by the synchronous self-timed write architecture and is documented in the functional description.

What is the role of the QVLD signal, and how is it timed relative to CQ/CQ?

QVLD is an edge-aligned valid-data indicator that asserts coincident with the first valid data word on Q[17:0] during a read burst. It rises and falls aligned to CQ and CQ edges-not to K/K-ensuring receiver logic can reliably gate data capture using echo clocks, even with board-level skew between K/K and CQ/CQ.