Cypress Semiconductor Corp CY7C1548KV18-450BZI

Overview

CY7C1548KV18 from Cypress Semiconductor is a 72-Mbit synchronous pipelined SRAM with DDR II+ architecture, configured as 4M × 18 (18-bit data bus), operating at 450 MHz with 2.0-cycle read latency and dual-clock (K/K) timing control. It delivers 900 Mbps effective data rate via double-data-rate transfers, uses HSTL I/O with VDDQ = 1.4V–1.8V, and integrates echo clocks (CQ/CQ) and QVLD for precise high-speed data capture in burst-mode memory subsystems.

For engineers reviewing the CY7C1548KV18 datasheet, CY7C1548KV18 pinout, CY7C1548KV18 application, or CY7C1548KV18 equivalent, key selection considerations include its 450 MHz clock support, 2-word burst capability, DOFF-configurable DDR I/II+ mode, 165-ball FBGA package, and synchronous self-timed write operation - all critical for high-bandwidth packet buffering and network switch fabric design.

Technical Context

The CY7C1548KV18 implements a synchronous pipelined architecture where addresses are latched on alternate rising edges of K and K, and read data bursts two 18-bit words sequentially on consecutive K/K edges. Its internal organization comprises two 2M × 18 arrays, enabling depth-expanded configurations without wait states.

It features a PLL-based timing engine for accurate data placement, supports both DDR I (1-cycle latency, DOFF = LOW) and DDR II+ (2-cycle latency, DOFF = HIGH) modes, and uses HSTL Class I inputs with variable-drive outputs matched to system impedance via ZQ calibration - all synchronized to K/K edge-triggered registers.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 13 mm × 15 mm × 1.4 mm body, RoHS-compliant, with 0.8 mm ball pitch and standard JEDEC MO-270AB footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72T3615L10BG and IS61WV102418B, the CY7C1548KV18 uniquely combines 450 MHz DDR II+, integrated echo clocks, and QVLD to reduce FPGA logic utilization by ~35% and eliminate board-level DQS routing - critical for space-constrained telecom and defense platforms.

Availability

CY7C1548KV18 is available at Aetrix Electronics and suitable for network packet buffering, telecom line card memory, high-speed test equipment memory, and avionics data acquisition requiring stable component supply, long-term lifecycle assurance, and Pb-free compliance.

Supply support for CY7C1548KV18 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 programmable logic solutions for industrial, automotive, and communications markets.

The CY7C1548KV18 belongs to Cypress's QDR II+ SRAM product line, designed specifically for ultra-low-latency, high-bandwidth memory interfacing in networking ASICs, FPGA-based accelerators, and real-time signal processing systems.

FAQ

What is the function of the DOFF pin on CY7C1548KV18?

The DOFF (PLL Turn Off) pin is an active-low control that disables the internal phase-locked loop. When asserted LOW, the device reverts to DDR I timing with 1-cycle read latency and maximum 167 MHz operation. When tied HIGH (e.g., via 10 kΩ pull-up), it enables full DDR II+ mode at up to 450 MHz with 2.0-cycle latency - allowing hardware-selectable performance modes without firmware changes.

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

The ZQ pin connects to an external resistor to ground (RQ) to calibrate the output driver impedance of DQ[17:0], CQ, and CQ to 0.2 × RQ. This dynamic calibration compensates for voltage and temperature drift, ensuring consistent 25–35 Ω output impedance. Proper ZQ termination eliminates signal reflections and overshoot on 450 MHz DDR buses, reducing the need for discrete series resistors and improving eye margin by ≥15%.

Can CY7C1548KV18 be used in depth-expanded memory configurations?

Yes - the CY7C1548KV18 supports seamless depth expansion due to automatic output tri-state control. When a read access is deselected, the device completes pending transactions and tri-states DQ[17:0] on the next K rising edge. This eliminates bus contention between multiple SRAMs and removes the need for external bus transceivers or wait-state insertion - verified in multi-chip 8M × 18 and 16M × 18 implementations.

What is the role of BWS[1:0] in write operations?

BWS[1:0] are active-low byte write select signals that enable partial-word writes without read-modify-write cycles. BWS0 controls DQ[8:0] and BWS1 controls DQ[17:9]. When either is deasserted, the corresponding 9-bit segment remains unaltered. This allows efficient updating of metadata fields or header sections within 18-bit packets - reducing average write latency by up to 40% compared to full-word writes in protocol processing applications.