Infineon Technologies CY7C11651KV18-400BZC

Overview

CY7C11651KV18 from Cypress Semiconductor is a 18-Mbit QDR® II+ SRAM with 512K × 36 organization, 4-word burst architecture, and 2.5-cycle read latency at 400 MHz. It features separate read/write ports, DDR interfaces on both ports (800 Mbps effective data rate), HSTL I/O, and operates with core VDD = 1.8 V ± 0.1 V and I/O VDDQ = 1.4–1.8 V. It is used in high-bandwidth packet buffering for network line cards and switch fabric controllers.

For engineers reviewing the CY7C11651KV18 datasheet, CY7C11651KV18 pinout, CY7C11651KV18 application, or CY7C11651KV18 equivalent, key selection criteria include burst depth, read latency mode (DOFF-controlled), byte write select granularity (BWS[3:0]), echo clock timing (CQ/CQ), and 165-ball FBGA package compatibility with high-speed PCB layout constraints.

Technical Context

This SRAM implements synchronous pipelined QDR II+ architecture with independent read and write ports sharing a multiplexed address bus. Address latching occurs on alternating rising edges of K and K clocks, enabling concurrent access without bus turnaround.

It integrates a PLL for precise DDR data placement, supports programmable impedance via ZQ pin, and uses echo clocks (CQ/CQ) with QVLD to simplify high-speed data capture. DOFF pin selects between 2.5-cycle (HIGH) and 1-cycle (LOW) read latency modes, maintaining functional alignment with legacy QDR I systems.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 13 mm × 15 mm × 1.4 mm body, 0.8 mm ball pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C11651KV18-450BZC, this 400 MHz variant offers lower power (1000 mA vs. 1100 mA) and relaxed timing margins, while AS7C331024P-15JIN trades all QDR II+ advantages for simplicity and legacy compatibility - making CY7C11651KV18 optimal for new high-speed packet-processing designs.

Availability

CY7C11651KV18 is available at Aetrix Electronics and suitable for network infrastructure, telecom baseband processing, and automated test equipment requiring stable component supply across multi-year production cycles.

Supply support for CY7C11651KV18 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 systems.

This device belongs to the QDR® II+ SRAM product line, engineered specifically for deterministic, high-bandwidth buffering in packet-switched networks and real-time signal processing architectures.

FAQ

What is the function of the DOFF pin on CY7C11651KV18?

The DOFF (Data-Off) pin configures read latency mode: when asserted HIGH, it enables 2.5-cycle latency for QDR II+ operation; when LOW, it reverts to 1-cycle latency compatible with QDR I timing. This pin is sampled synchronously on the K clock rising edge at power-up and remains latched until reset. It does not support dynamic switching during active operation.

How many address bits are required for CY7C11651KV18's 512K × 36 organization?

CY7C11651KV18 requires 17 address bits (A[16:0]) because its internal memory array is organized as four 128K × 36 banks. The 17-bit address space accesses 131,072 locations per bank, and bank selection is implicit via port control (RPS/WPS) and burst sequencing-not decoded address lines.

Can CY7C11651KV18 operate with VDDQ = 1.5 V while VDD = 1.8 V?

Yes - the datasheet explicitly permits VDDQ = 1.4 V to 1.8 V independently of core VDD = 1.8 V ± 0.1 V. At VDDQ = 1.5 V, HSTL output drive strength is reduced but remains compliant with Class I specifications, and input thresholds adapt accordingly. System-level timing margins must be verified per AC characteristics table at that VDDQ.

What is the purpose of the ZQ pin, and how must it be connected?

ZQ is a dedicated reference pin for on-die impedance calibration of HSTL output drivers. It must be connected to a single 240 Ω ± 1% resistor tied to ground, placed within 5 mm of the FBGA pad. No capacitors or series resistors are allowed. Calibration occurs automatically at power-up and can be retriggered via JTAG instruction, ensuring consistent output impedance across voltage and temperature.