Lattice LC4128V-75T128-10I: A Comprehensive Technical Overview of the 3V CPLD

The Lattice LC4128V-75T128-10I represents a significant implementation of Complex Programmable Logic Device (CPLD) technology, designed for a broad range of low-power, high-performance control applications. As a member of the high-density ispMACH® 4000V CPLD family, this device combines a robust 3.3V core voltage architecture with advanced in-system programmability, making it a versatile solution for modern digital design.

At the heart of this CPLD are 128 macrocells, organized into four Function Blocks, each containing 32 macrocells. This structure provides a flexible and efficient logic fabric. The device boasts a maximum of 98 user I/O pins, offering ample connectivity for interfacing with external components such as memories, microcontrollers, and bus interfaces. These I/Os are 5V tolerant, a critical feature that allows for seamless communication with legacy 5V systems without requiring level shifters, thereby simplifying board design and reducing component count.

Performance is a key characteristic of the LC4128V-75T128-10I. The `-10` speed grade denotes a pin-to-pin logic propagation delay as fast as 10 ns, enabling the device to handle high-speed control tasks and state machine operations efficiently. The internal global clock network supports clock frequencies exceeding 200 MHz, ensuring synchronization across the entire device without significant skew.

A defining feature of this CPLD is its in-system programmability (ISP) via the IEEE 1149.1 (JTAG) interface. This allows for rapid design iterations and field upgrades without physically removing the device from the circuit board, drastically reducing development time and cost. The device is also compliant with the IEEE 1532 standard for in-system configuration, further enhancing its programmability.

Power efficiency is central to its 3V design. Operating from a single 3.3V power supply, the device utilizes Lattice's advanced CMOS technology to achieve low static and dynamic power consumption. This makes it particularly suitable for portable, battery-operated, and power-sensitive applications where thermal management is a concern.

The device is housed in a 128-pin Thin Quad Flat Pack (TQFP) package, which offers a compact footprint suitable for space-constrained PCB designs while providing good thermal and electrical performance.

In application, the LC4128V-75T128-10I excels in roles such as power-on sequencing, bus bridging (e.g., translating between PCI and local buses), address decoding, and system configuration management. Its ability to integrate multiple discrete logic components into a single, reprogrammable chip significantly enhances system reliability and reduces overall design complexity.

ICGOOODFIND: The Lattice LC4128V-75T128-10I stands out as a highly capable 3.3V CPLD, offering an optimal balance of logic density, high-speed performance, and low power consumption. Its 5V tolerant I/Os and superior in-system programmability make it an enduringly popular choice for designers seeking a reliable and flexible glue logic solution.

Keywords: CPLD, 3.3V Core, In-System Programmability (ISP), 5V Tolerant I/O, Macrocell