Infineon Technologies CY7C1420KV18-250BZXC

Overview

CY7C1420KV18-250BZXC from Cypress Semiconductor is a 36-Mbit (1M × 36) synchronous DDR II SRAM with two-word burst architecture, 250 MHz maximum clock frequency, 1.8 V core supply, and HSTL I/O compatible with 1.5 V or 1.8 V VDDQ. It supports 1-cycle read latency in DDR-I mode (DOFF = LOW) and 1.5-cycle latency in DDR-II mode (DOFF = HIGH), and is used in high-bandwidth packet buffering for network switches and routers.

For engineers reviewing the CY7C1420KV18-250BZXC datasheet, CY7C1420KV18-250BZXC pinout, CY7C1420KV18-250BZXC application, or CY7C1420KV18-250BZXC equivalent, key selection criteria include DDR-II burst timing, echo clock (CQ/CQ) synchronization, dual-clock domain support (K/K and C/C), and 165-ball FBGA package compatibility with high-speed memory bus layouts.

Technical Context

This device implements a synchronous pipelined SRAM core with an internal 1-bit burst counter that increments the least significant address bit (A0) to deliver two consecutive 36-bit words per access. All address, control, and data inputs are registered on rising edges of K and K clocks, enabling precise setup/hold timing at 250 MHz.

Read data is driven synchronously on rising edges of C and C output clocks (or K/K in single-clock mode), with echo clocks CQ/CQ phase-aligned to C/C to eliminate board-level skew. The PLL ensures accurate data placement relative to echo clocks, and ZQ pin enables programmable output impedance matching to system trace impedance.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C33618B-250BIN and IS61WV102436BLL-250TQLI, CY7C1420KV18-250BZXC uniquely combines DDR-II configurable latency, echo clocks for skew-insensitive capture, and on-die impedance tuning - making it optimal for new designs requiring timing robustness at 250 MHz.

Availability

CY7C1420KV18-250BZXC is available at Aetrix Electronics and suitable for network packet buffering, telecom line card memory, industrial PLC data logging, and ATE pattern memory applications requiring stable component supply and long-term obsolescence planning.

Supply support for CY7C1420KV18-250BZXC 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.

CY7C1420KV18 belongs to Cypress's DDR II SRAM product line, designed specifically for high-bandwidth, low-latency buffering in networking ASICs and FPGA-based infrastructure equipment where deterministic burst access and signal integrity at >500 MT/s are critical.

FAQ

What is the function of the DOFF pin on CY7C1420KV18-250BZXC?

The DOFF (DDR Off) pin configures the device's read latency mode: when asserted HIGH, it enables DDR-II operation with 1.5-cycle latency; when LOW, it forces DDR-I mode with 1-cycle latency. This pin directly controls internal timing paths and must be set statically at power-up - it is not dynamically switchable during operation.

Can CY7C1420KV18-250BZXC operate with only K and K clocks, without C and C?

Yes. When C and C are unconnected or tied to static logic levels, the device defaults to single-clock mode: read data is driven on rising edges of K and K instead of C and C. In this mode, echo clocks CQ/CQ are generated relative to K/K, preserving timing alignment but eliminating deskew flexibility across multiple devices.

What is the purpose of the ZQ pin, and how should it be terminated?

ZQ is used for on-die output impedance calibration. It must be connected to a 240 Ω resistor to ground to set DQ and CQ output drivers to 48 Ω ±10%. Direct connection to VDDQ enables minimum impedance (~30 Ω); connection to GND or leaving it floating is prohibited and may cause undefined behavior or damage.

Does CY7C1420KV18-250BZXC support byte-write masking across all 36 bits?

Yes. Four synchronous byte write select inputs (BWS[3:0]) enable independent masking of four 9-bit lanes: BWS0 controls D[8:0], BWS1 controls D[17:9], BWS2 controls D[26:18], and BWS3 controls D[35:27]. All BWS signals are sampled on the same K/K edges as write data, allowing true partial writes without read-modify-write overhead.