Cypress Semiconductor Corp CY7C1393KV18-250BZI

Overview

CY7C1393KV18-250BZI from Cypress Semiconductor is a 1M × 18 (18-Mbit), 250 MHz DDR II Synchronous SRAM with separate I/O architecture, two-word burst read/write capability, echo clocks (CQ/CQ), and programmable impedance matching via ZQ. It operates at 1.8 V core with HSTL I/O supporting 1.4–1.8 V VDDQ, and is used in high-bandwidth packet buffering for network switches and FPGA co-processor memory interfaces.

For engineers reviewing the CY7C1393KV18-250BZI datasheet, CY7C1393KV18-250BZI pinout, CY7C1393KV18-250BZI application, or CY7C1393KV18-250BZI equivalent, key selection criteria include DDR II timing compliance (1.5-cycle read latency with DOFF HIGH), 165-ball FBGA package compatibility, byte write select (BWS0/BWS1) control for partial writes, and JTAG 1149.1 test access support.

Technical Context

This SRAM implements a synchronous pipelined architecture with independent read and write ports sharing a common address bus. Address latching occurs on alternating rising edges of K/K clocks, while write data is registered on both K and K edges - enabling true double-data-rate input capture without bus turnaround.

Read data is output-synchronized to C/C echo clocks (or K/K in single-clock mode), with CQ/CQ tightly aligned to output data edges to eliminate board-level skew compensation. The integrated PLL ensures precise data placement, and DOFF pin selection toggles between DDR I (1-cycle latency) and DDR II (1.5-cycle latency) operation modes.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS7C3256A-15JCIN and IS61WV102418BLL-10BLI, CY7C1393KV18-250BZI delivers 5× higher effective bandwidth (500 MT/s vs. ≤100 MT/s), deterministic DDR II timing with echo clocks, and burst efficiency - making it uniquely suited for modern high-speed serial fabric interfaces.

Availability

CY7C1393KV18-250BZI is available at Aetrix Electronics and suitable for network packet buffering, FPGA co-processor memory, and telecom line card buffering requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for CY7C1393KV18-250BZI 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 memory, microcontrollers, and connectivity solutions for industrial, automotive, and communications markets.

CY7C1393KV18 belongs to Cypress's DDR II SIO SRAM product line, designed specifically for high-bandwidth, low-latency buffering in packet-switched networks and FPGA-accelerated systems where deterministic timing and burst efficiency are critical.

FAQ

What is the function of the DOFF pin on CY7C1393KV18-250BZI?

The DOFF (DDR Off) pin selects between DDR I and DDR II read latency modes. When DOFF is HIGH, the device operates in DDR II mode with 1.5-cycle read latency and optimized burst timing. When DOFF is LOW (or tied to VSS), it reverts to DDR I mode with 1-cycle latency and simplified timing margins - allowing hardware-level adaptation to system timing constraints without firmware changes.

Can CY7C1393KV18-250BZI operate with only one clock (K) instead of differential K/K?

Yes. The device supports single-clock mode where K is used as the sole input clock and K is tied to VSS or left floating (per datasheet guidance). In this mode, all synchronous inputs and outputs are referenced to K only, and read data is driven on rising edges of K/K (i.e., same edge twice), simplifying clock distribution at the cost of reduced timing margin versus true differential operation.

How does the ZQ pin enable impedance calibration?

ZQ connects to an external 240 Ω resistor to ground. During calibration (initiated by controller or internal power-up sequence), the SRAM measures this reference and adjusts its HSTL output driver strength to match - ensuring consistent 240 Ω ±15% termination across voltage, temperature, and process variation. This maintains signal integrity without requiring board-level series resistors.

Is CY7C1393KV18-250BZI pin-compatible with CY7C1392KV18-250BZI?

No. Although both use the same 165-ball FBGA package and share many pin functions, their data bus widths differ: CY7C1393KV18 uses D[17:0]/Q[17:0] and BWS0/BWS1, while CY7C1392KV18 uses D[7:0]/Q[7:0] and NWS0/NWS1. Pin assignments for data, write select, and array-specific signals are not interchangeable - PCB layout and firmware must be redesigned for substitution.