Infineon Technologies CY7C375I-125AC

Overview

CY7C375I-125AC from Cypress Semiconductor is a 128-macrocell In-System Reprogrammable (ISR™) Complex Programmable Logic Device (CPLD) with eight logic blocks, 128 I/O pins, and four dedicated clock inputs. It operates at 125 MHz maximum frequency (f_MAX), delivers 10 ns propagation delay (t_PD), and supports both 3.3V and 5.0V I/O voltage modes - used in PCI-compliant interface bridging, legacy bus control, and FPGA configuration management.

For engineers reviewing the CY7C375I-125AC datasheet, CY7C375I-125AC pinout, CY7C375I-125AC application, or CY7C375I-125AC equivalent, key selection criteria include JTAG-based ISR capability, deterministic timing without fanout-dependent delays, bus-hold on all I/Os, and dual-voltage I/O compatibility for mixed-signal board integration.

Technical Context

The CY7C375I-125AC implements the FLASH370i™ architecture with a Programmable Interconnect Matrix (PIM) enabling uniform, speed-predictable routing between eight logic blocks. Each block contains 16 macrocells fed by a 72 × 86 product-term array and dynamic product-term allocator supporting steering and sharing.

It features four global clocks (CLK0–CLK3), one dedicated input (I2), and JTAG-controlled ISR via SDI/SDO/ISREN pins. Bus-hold circuitry replaces external pull-ups on all 128 I/Os and dedicated inputs, maintaining last-driven state during three-state transitions to reduce noise and simplify prototyping.

Key Specifications

Pinout & Package

Package: 160-pin TQFP (Thin Quad Flat Package), 24 mm × 24 mm, 0.5 mm pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CPLD-based interface and control applications.

Compared with XC95144XL-10TQ144I and EPM7128SLC84-10, the CY7C375I-125AC uniquely combines 3.3V/5V I/O flexibility, integrated bus-hold, and true in-system reprogrammability - reducing BOM count, simplifying layout, and enabling post-deployment logic updates without hardware intervention.

Availability

CY7C375I-125AC is available at Aetrix Electronics and suitable for PCI-compliant interface bridges, FPGA configuration managers, legacy bus controllers, and embedded bootloader logic requiring stable component supply across industrial temperature ranges (–40°C to +85°C).

Supply support for CY7C375I-125AC 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 U.S.-based semiconductor company specializing in programmable logic, memory, and USB/USB-C solutions for industrial, automotive, and communications markets.

The CY7C375I-125AC belongs to the UltraLogic™ FLASH370i™ CPLD family, designed specifically for high-reliability, mixed-voltage system integration where deterministic timing, field-upgradable logic, and reduced external components are critical.

FAQ

What voltage levels must be applied to VCCINT and VCCIO for proper operation?

VCCINT must always be supplied with 5.0V ±0.25V (commercial) or ±0.5V (industrial); VCCIO may be set to either 3.3V ±0.3V or 5.0V ±0.25V depending on I/O interface requirements. Mixing VCCIO voltages across pins is not supported - all VCCIO pins must share the same rail. Incorrect VCCINT voltage risks permanent damage to internal logic.

Does the CY7C375I-125AC require external pull-up resistors on JTAG or I/O pins?

No. All 128 I/O pins and dedicated inputs (including ISREN, SDI, SDO, CLK0–CLK3) feature integrated bus-hold circuitry that actively retains the last driven logic state during high-impedance conditions. This eliminates the need for external pull-up or pull-down resistors in most applications, including JTAG boundary-scan and tri-stated data buses.

How does the Programmable Interconnect Matrix (PIM) affect timing predictability?

The PIM provides a fixed-delay, full-crosspoint interconnect between logic blocks and I/Os - unlike FPGA routing fabrics, it introduces no variable delay based on fanout or placement. As confirmed in the datasheet, tPD, tS, and tCO remain constant regardless of design complexity or resource utilization, enabling timing-closure assurance without iterative place-and-route analysis.

Can the CY7C375I-125AC be reprogrammed while soldered on a live PCB?

Yes. The device supports true In-System Reprogrammability (ISR™) via its JTAG interface (SDI, SDO, ISREN, TCK, TMS, TDI, TDO). Reprogramming occurs at standard 3.3V or 5.0V VCCIO levels - no elevated programming voltage is required. The process preserves pin states and does not disrupt adjacent circuitry, making it suitable for field firmware updates and design validation.