Lattice LC4128ZE-7TN100C: A Comprehensive Technical Overview of the CPLD

In the realm of digital logic design, Complex Programmable Logic Devices (CPLDs) remain a cornerstone for "glue logic," system configuration, and control plane management. Among these, the Lattice LC4128ZE-7TN100C stands out as a robust and versatile solution, balancing density, performance, and power efficiency. This article provides a detailed technical examination of this specific CPLD.

The LC4128ZE is a member of Lattice Semiconductor's high-performance, low-power ispMACH® 4000ZE CPLD family. The "128" in its designation signifies its capacity, containing 128 macrocells. These macrocells are the fundamental building blocks of the CPLD, organized into four Function Blocks, each with 32 macrocells. This architecture provides a predictable, fast timing model, which is a key advantage of CPLDs over FPGAs for simple, deterministic tasks.

A critical specification is its logic density. With 128 macrocells, it is well-suited for applications requiring a moderate amount of logic, such as interfacing between different logic families, implementing state machines, or handling address decoding. The device is housed in a 7TN100C package, which denotes a 100-pin Thin Quad Flat Pack (TQFP). This surface-mount package offers a compact footprint, making it suitable for space-constrained PCB designs.

Performance is a hallmark of this device. The "-7" in its speed grade indicates a pin-to-pin logic propagation delay of 7.0 ns maximum, enabling high-performance operation for critical control paths. This speed ensures that the CPLD can efficiently bridge timing gaps between larger processors or ASICs without becoming a system bottleneck.

A significant feature of the 4000ZE family is its ultra-low power consumption. The device operates on a 1.8V core voltage with 3.3V or 2.5V I/O capability. This low core voltage dramatically reduces static and dynamic power dissipation, making it an ideal choice for portable, battery-powered, and thermally sensitive applications where power efficiency is paramount.

The I/O capabilities are another strong point. The device features up to 80 user I/O pins (in the 100-pin package), offering substantial connectivity. These pins support various I/O standards, including LVCMOS 3.3V/2.5V/1.8V/1.5V and LVTTL, providing excellent flexibility for interfacing with a wide range of other components in a modern electronic system.

In-system programmability (ISP) is facilitated through a JTAG (IEEE 1149.1) interface. This allows for rapid design iterations and field upgrades after the device has been soldered onto a circuit board, significantly reducing development time and cost.

Typical applications for the LC4128ZE-7TN100C include:

Bus bridging and interface logic (e.g., PCI to local bus).

Power-up sequencing and system configuration for FPGAs and ASICs.

Data path control and signal gating.

State machine implementation for complex control logic.

I/O expansion for microcontrollers.

ICGOOODFIND: The Lattice LC4128ZE-7TN100C is a highly capable CPLD that delivers an optimal blend of moderate logic capacity, high-speed performance, and ultra-low power consumption. Its predictable timing, flexible I/O options, and in-system programmability make it a reliable and efficient choice for a vast array of control-oriented logic tasks in modern electronic designs.

Keywords: CPLD, Low-Power, High-Speed, Programmable Logic, JTAG.