Infineon Technologies CG7618AA

Overview

CG7618AA from Cypress Semiconductor is a 36-Mbit DDR II synchronous SRAM configured as 2M × 18, operating at 333 MHz with double-data-rate interface (666 MT/s), 1.8 V core supply, and HSTL I/O compatible with 1.5 V or 1.8 V VDDQ. It implements two-word burst addressing, echo clocks (CQ/CQ), and PLL-based data placement for high-speed networking buffers and packet memory in telecom line cards.

For engineers reviewing the CG7618AA datasheet, CG7618AA pinout, CG7618AA application, or CG7618AA equivalent, this device supports precise DDR timing via dual K/K and C/C clocks, offers programmable output impedance via ZQ, enables byte-selectable writes with BWS[1:0], and delivers 1.5-cycle read latency when DOFF = HIGH - critical for deterministic latency in real-time switching fabric designs.

Technical Context

The CG7618AA integrates a pipelined SRAM core with synchronous peripheral logic, using rising edges of complementary K/K clocks to latch addresses and write data, and C/C clocks to drive read data with matched flight time. Its burst counter increments A0 internally to deliver two consecutive 18-bit words per access.

It supports both dual-clock (K/K + C/C) and single-clock (K/K only) modes, with echo clocks CQ/CQ phase-aligned to C/C for simplified data capture. The ZQ pin calibrates output driver impedance to 0.2 × RQ (RQ tied to ground), ensuring signal integrity on high-speed parallel buses.

Key Specifications

Pinout & Package

CG7618AA is housed in a 165-ball Fine-Pitch Ball Grid Array (FBGA) package measuring 13 mm × 15 mm × 1.4 mm, with 0.8 mm ball pitch and Pb-free option available. Pin assignments follow JEDEC MO-245AC standard.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DDR II SRAM applications.

Compared with CY7C1416KV18 and IS45S16160F-75BLI, CG7618AA uniquely delivers 333 MHz DDR-II performance with echo clocks and ZQ calibration - enabling deterministic, high-fidelity memory access in telecom and networking equipment where timing predictability is non-negotiable.

Availability

CG7618AA is available at Aetrix Electronics and suitable for telecom line card design, high-speed packet switching, network processor co-processing, and real-time protocol analysis requiring stable component supply across extended product lifecycles.

Supply support for CG7618AA 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.

CG7618AA belongs to Cypress's DDR II SRAM product line, engineered specifically for deterministic, low-latency memory subsystems in carrier-grade networking infrastructure where signal integrity and timing precision are mission-critical.

FAQ

What is the function of the DOFF pin on CG7618AA?

The DOFF (Data Output OFFset) pin configures read latency mode: when asserted HIGH, it enables DDR-II operation with 1.5-cycle latency for improved timing margin; when LOW, it reverts to DDR-I behavior with 1-cycle latency. This setting directly affects the number of clock cycles between address assertion and valid data output, and must be held stable during operation.

Can CG7618AA operate without external C/C clocks?

Yes - CG7618AA supports single-clock mode where K/K serve as both input and output clocks. In this configuration, read data is driven on K/K rising edges instead of C/C, and echo clocks CQ/CQ are derived from K/K. However, dual-clock mode is required to achieve full timing margin and deskew benefits in multi-device systems.

How does ZQ calibration affect signal integrity?

ZQ calibration adjusts the output driver impedance of DQ and CQ pins to match the system data bus (typically 50 Ω). By connecting an external resistor RQ (e.g., 240 Ω) from ZQ to ground, the device sets its output impedance to 0.2 × RQ = 48 Ω - minimizing reflections and maintaining clean eye diagrams at 666 MT/s, especially over long PCB traces.

Is CG7618AA pin-compatible with CY7C1420KV18?

No - CG7618AA (2M × 18) and CY7C1420KV18 (1M × 36) share the same 165-ball FBGA package but differ in pin mapping: BWS[3:0] and DQ[35:0] occupy different ball locations, and address count differs (21 vs. 20 bits). Interchange requires PCB redesign and firmware adaptation due to distinct data width and burst addressing logic.