Cypress Semiconductor Corp CY7C1570KV18-550BZXI

Overview

CY7C1570KV18 from Cypress Semiconductor is a 72-Mbit synchronous pipelined SRAM with DDR II+ architecture, configured as 2M × 36 bits and operating at 550 MHz clock frequency (1100 MT/s data rate). It features 2.5-cycle read latency when DOFF is HIGH, HSTL I/O with programmable impedance via ZQ pin, and dual echo clocks (CQ/CQ) for precise DDR data capture. Used in high-bandwidth networking line cards and packet buffer subsystems requiring deterministic low-latency memory access.

For engineers reviewing the CY7C1570KV18 datasheet, CY7C1570KV18 pinout, CY7C1570KV18 application, or CY7C1570KV18 equivalent, key selection criteria include its 2M × 36 organization, 550 MHz K-clock support, DOFF-configurable latency mode (DDR II+ vs DDR I), HSTL-18 I/O compliance, and 165-ball FBGA (13 × 15 × 1.4 mm) package compatibility with high-density PCB layouts.

Technical Context

This device implements a synchronous burst SRAM core with dual-edge DDR interface logic, where all address, control, and data signals are registered on rising edges of complementary K/K clocks. Internal pipelining enables back-to-back read initiation every K cycle, while the PLL ensures accurate data placement relative to echo clocks CQ/CQ.

The CY7C1570KV18 supports byte-selectable writes via four BWS inputs (BWS[3:0]), enabling partial 36-bit word updates without read-modify-write cycles. Its QVLD signal provides edge-aligned indication of valid output data, and ZQ pin allows dynamic output impedance calibration to match system trace impedance - critical for signal integrity above 500 MHz.

Key Specifications

Pinout & Package

Available in a 165-ball fine-pitch FBGA package (13 × 15 × 1.4 mm, 0.8 mm ball pitch), RoHS-compliant and offered in both Pb-free and non-Pb-free variants. Pin assignments are optimized for DDR timing closure and signal integrity in high-speed memory subsystems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C362000B-15JIN and MT47H64M16HR-37E, the CY7C1570KV18 uniquely delivers 550 MHz DDR II+ operation with integrated PLL, echo clocks, and QVLD - enabling true deterministic sub-2-ns read response in high-reliability telecom and test equipment designs.

Availability

CY7C1570KV18 is available at Aetrix Electronics and suitable for high-speed packet buffering, telecom line card memory, network processor co-processor memory, and automated test equipment pattern storage requiring stable component supply and long-term lifecycle support.

Supply support for CY7C1570KV18 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 CY7C1570KV18 belongs to Cypress's QDR II+/DDR II+ SRAM product line, designed specifically for deterministic, low-latency, high-bandwidth memory interfacing in networking and test instrumentation systems where timing predictability is critical.

FAQ

What is the function of the DOFF pin on CY7C1570KV18?

The DOFF (PLL Turn Off) pin is an active-low control that disables the internal PLL when pulled to ground. In this state, the device operates in DDR I mode with 1-cycle read latency and maximum clock frequency reduced to 167 MHz. For full DDR II+ performance at 550 MHz with 2.5-cycle latency, DOFF must be tied HIGH via a ≤10 kΩ pull-up resistor to VDDQ.

How does the ZQ pin affect output drive strength?

The ZQ pin connects to an external resistor (RQ) to ground, allowing the device to calibrate its output driver impedance to 0.2 × RQ. This matches the SRAM's DQ and CQ outputs to the PCB trace impedance, minimizing reflections and improving signal integrity. If ZQ is tied directly to VDDQ, the device enters minimum-impedance mode (no calibration), which may increase power but simplify layout.

Can CY7C1570KV18 be used in depth-expanded memory configurations?

Yes - the device supports seamless depth expansion using standard address decoding. When one device deselects, its outputs tristate automatically on the next rising edge of K, eliminating bus contention. The QVLD signal remains synchronized across devices, enabling clean handoff between adjacent SRAMs in multi-chip memory banks without added wait states.

What is the purpose of the CQ and CQ echo clocks?

CQ and CQ are free-running, phase-aligned copies of the K and K input clocks, respectively. They are driven out synchronously with DQ data and serve as dedicated capture clocks for external logic (e.g., FPGA input registers), removing the need for complex deskew circuits or delay-locked loops to align data and clock paths in high-speed designs.