Infineon Technologies CY7C1568V18-400BZXCT

Overview

CY7C1568V18 from Cypress Semiconductor is a 72-Mbit synchronous pipelined SRAM with DDR-II+ architecture, configured as 4M × 18 (18-bit data bus), operating at 400 MHz clock frequency with 2.5-cycle read latency and double-data-rate interface delivering 800 MT/s effective throughput. It uses HSTL I/O, 1.8V core supply (VDD = 1.8V ± 0.1V), and 1.4V–1.8V I/O supply (VDDQ), and is packaged in a 165-ball FBGA (15 × 17 × 1.4 mm) for high-speed networking and packet buffering applications.

For engineers reviewing the CY7C1568V18 datasheet, CY7C1568V18 pinout, CY7C1568V18 application, or CY7C1568V18 equivalent, this device is selected for burst-mode, low-latency memory interfacing in FPGA-attached buffer systems requiring precise echo-clock–synchronized data capture, JTAG-testable DDR SRAM with DLL-based timing alignment and variable-drive HSTL outputs.

Technical Context

The CY7C1568V18 implements a synchronous pipelined architecture with dual input clocks (K and K̄) to control all address, control, and data transfers on rising edges only. Its internal organization comprises two 2M × 18 arrays, enabling 2-word burst reads/writes per access cycle.

It integrates a Delay Lock Loop (DLL) for accurate data placement relative to echo clocks CQ/CQ̄, supports synchronous self-timed writes, and provides QVLD to indicate valid output data edge-aligned with CQ/CQ̄. The ZQ pin enables dynamic output impedance tuning to match system bus termination.

Key Specifications

Pinout & Package

Package: 165-ball Fine-Pitch Ball Grid Array (FBGA), 15 mm × 17 mm × 1.4 mm body, 0.8 mm ball pitch, RoHS-compliant (Pb-free option available).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1566V18 and CY7C1570V18, the CY7C1568V18 uniquely balances 18-bit bus width and 4M depth-ideal for modern FPGA I/O standards-while retaining full pin and timing compatibility within the CY7C15xxV18 family for scalable memory design.

Availability

CY7C1568V18 is available at Aetrix Electronics and suitable for high-speed packet buffering, FPGA-based protocol acceleration, and telecom line card memory applications requiring stable component supply, long-lifecycle support, and guaranteed Pb-free compliance.

Supply support for CY7C1568V18 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 communications, industrial, and automotive systems, emphasizing signal integrity, timing precision, and long-term manufacturability.

The CY7C15xxV18 DDR-II+ SRAM product line was engineered specifically for deterministic, low-latency burst memory interfacing in FPGA- and ASIC-based infrastructure equipment where DDR SDRAM latency and refresh overhead are unacceptable.

FAQ

What is the function of the DOFF pin on CY7C1568V18?

The DOFF (DLL Turn Off) pin is an active-LOW control that disables the internal Delay Lock Loop. When pulled to ground, the device operates in DDR-I mode with reduced maximum frequency (≤167 MHz) and relaxed timing. For normal DDR-II+ operation at 400 MHz, DOFF must be pulled up via ≤10 kΩ resistor to VDDQ.

How does the ZQ pin affect output impedance calibration?

The ZQ pin connects to an external resistor (RQ) tied to ground, enabling on-die calibration of CQ, CQ̄, and DQ[17:0] output drivers to 0.2 × RQ. This dynamically matches output impedance to the system data bus, minimizing reflections and improving signal integrity. Leaving ZQ unconnected or tying it to GND is prohibited.

Can CY7C1568V18 operate with VDDQ = 1.4V?

Yes. Unlike standard QDR consortium specifications (1.5V ± 0.1V), CY7C1568V18 supports VDDQ from 1.4V to VDD (1.8V). At 1.4V, HSTL output drive strength is reduced but remains compliant with Class I HSTL receiver thresholds, enabling lower-power operation in thermally constrained systems.

What determines the burst length and word size in CY7C1568V18?

The burst length is fixed at 2 words per access by the DDR-II+ architecture. Word size is physically defined by the 4M × 18 organization: each address location delivers two sequential 18-bit words on DQ[17:0], with no user-configurable burst length or data width-this is hardwired in silicon and reflected in the 165-ball FBGA pinout.