Infineon Technologies CY7C4235V-15ASXC

Overview

CY7C4235V-15ASXC from Cypress Semiconductor is a 2K × 18-bit (3,686-word) low-voltage synchronous FIFO memory with 3.3 V operation, 67 MHz maximum clock frequency, 15 ns read/write cycle time, and 5 V-tolerant inputs. It serves as a high-speed data buffer in asynchronous interface bridging between mismatched clock domains, supporting simultaneous read/write with programmable Almost Full/Almost Empty flags.

For engineers reviewing the CY7C4235V-15ASXC datasheet, CY7C4235V-15ASXC pinout, CY7C4235V-15ASXC application, or CY7C4235V-15ASXC equivalent, key selection criteria include depth-expansion capability, synchronous flag timing alignment, retransmit functionality for packet recovery, and STQFP-64 packaging compatibility with industrial PCB layouts.

Technical Context

The CY7C4235V-15ASXC implements dual-clock FIFO architecture with independent WCLK and RCLK inputs, enabling true asynchronous read/write operation. Its 2,048 × 18-bit SRAM array uses separate read and write pointers with overflow/underflow protection logic to prevent invalid access.

Status flags-EF, FF, PAE, PAF, and WXO/HF-are synchronized to respective clocks: EF and PAE to RCLK, FF and PAF to WCLK. The VCC/SMODE pin selects synchronous (VSS tie) or asynchronous (VCC tie) flag behavior, directly affecting timing predictability in deterministic systems.

Key Specifications

Pinout & Package

Package: 64-pin 10 × 10 mm STQFP (Small Thin Quad Flat Package), RoHS-compliant, 0.5 mm pitch, thermal pad exposed on underside.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous FIFO applications.

Compared with IDT72V2115L15PF and NB3N5002MNR2G, the CY7C4235V-15ASXC uniquely combines depth expansion, retransmit, and configurable flag synchronization-making it optimal for scalable, fault-resilient, multi-clock embedded buffers where deterministic recovery and layout flexibility are design requirements.

Availability

CY7C4235V-15ASXC is available at Aetrix Electronics and suitable for communications interface bridges, multiprocessor data exchange, high-speed data acquisition, and industrial protocol gateways requiring stable component supply across extended product lifecycles.

Supply support for CY7C4235V-15ASXC 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 interface ICs for industrial, automotive, and communications systems, emphasizing signal integrity and long-term supply stability.

The CY7C42X5V family was developed specifically for deterministic, low-latency data buffering in mixed-clock-domain systems-targeting applications where asynchronous handshaking introduces unacceptable jitter or software overhead.

FAQ

What is the function of the VCC/SMODE pin on CY7C4235V-15ASXC?

The VCC/SMODE pin configures the synchronization behavior of the Programmable Almost Empty (PAE) and Programmable Almost Full (PAF) flags. When tied to VSS (ground), PAE becomes synchronized to RCLK and PAF to WCLK-ensuring deterministic timing relative to respective clock domains. When tied to VCC, both flags operate asynchronously, offering faster response but requiring external metastability mitigation.

Can CY7C4235V-15ASXC be used in single-clock mode?

Yes. WCLK and RCLK inputs may be connected to the same clock source for single-clock operation. In this configuration, the FIFO behaves as a synchronous buffer with read and write operations aligned to one clock edge, retaining all status flag functionality and retransmit capability-ideal for simpler systems where clock domain separation is not required.

How does the retransmit (RT) feature work in standalone mode?

In standalone mode, asserting a HIGH pulse on the RT pin resets the internal read pointer to the first physical FIFO location. Subsequent reads output previously written data in order, enabling hardware-level packet replay. WCLK and RCLK must be disabled during and for tRTR (≥10 ns) after the RT pulse to ensure pointer reset completion and avoid race conditions.

Is depth expansion supported across different CY7C42X5V densities?

No. Depth expansion requires identical density and timing grade devices. CY7C4235V-15ASXC (2K × 18) must be cascaded only with other CY7C4235V-15ASXC units-not with CY7C4225V (1K) or CY7C4245V (4K)-to maintain consistent flag decoding, pointer arithmetic, and cascade timing margins as specified in the functional description.