Lattice PALCE22V10Q-15JC/5: A Comprehensive Technical Overview of the 5V 24-Pin PLD

In the realm of digital logic design, Programmable Logic Devices (PLDs) have served as fundamental building blocks, offering a flexible bridge between standard fixed-logic ICs and full-custom ASICs. Among these, the Lattice PALCE22V10Q-15JC/5 stands as a classic and robust implementation, representing a pinnacle of 5V erasable PLD technology. This article provides a detailed technical examination of this specific device.

The PALCE22V10Q is a high-performance, electrically erasable CMOS PLD. Its architecture is centered around a programmable AND array that feeds fixed OR terms to ten output logic macrocells (OLMCs). This macrocell-based architecture is the core of its flexibility, as each of the 10 outputs can be individually configured for combinatorial or registered operation. Furthermore, each output can be programmed for active-high or active-low polarity and can be set as an input, output, or bidirectional pin, providing significant design versatility.

The part number itself, PALCE22V10Q-15JC/5, encodes its key specifications:

PALCE: Denotes a PAL device built in CMOS technology that is Electrically Erasable.

22: Specifies the number of dedicated inputs.

V10: Indicates the ten output macrocells with variable architecture.

Q: Signifies Qualified for automotive or high-reliability industrial applications.

-15: This is a critical speed grade, indicating a maximum pin-to-pin combinatorial delay of 15 ns and a maximum clock frequency of up to 55.6 MHz, ensuring strong performance for a wide array of state machine and glue logic applications.

JC: Defines the package type—a 28-pin Plastic Leaded Chip Carrier (PLCC). The "JC" suffix is standard for a PLCC package.

/5: Explicitly confirms the device operates at a 5V core voltage, a standard for legacy TTL-compatible systems.

The device is housed in a 28-pin PLCC package, though it is commonly referred to as a "24-pin" logic device due to its 10 I/O pins, 12 dedicated inputs, 1 dedicated clock input, and 1 pin for the global output enable. The remaining pins are dedicated to power (VCC) and ground (GND). The use of EE CMOS technology was a major advancement over older bipolar parts, offering significantly lower static power consumption and the immense benefit of reprogrammability. Designs could be revised and bugs fixed without physically replacing the IC, drastically accelerating development cycles.

Typical applications for the PALCE22V10Q-15JC were vast, including address decoding, state machine implementation, bus interfacing, and combining multiple simple TTL logic chips into a single, more integrated and reliable package. It served as a cornerstone for "glue logic" in countless systems, from computer peripherals and telecommunications equipment to industrial control systems.

ICGOODFIND: The Lattice PALCE22V10Q-15JC/5 is a quintessential high-performance 5V EE CMOS PLD. Its defining features of 15ns speed, 10 configurable macrocells, and 5V operation made it an industry workhorse for logic integration. While modern CPLDs and FPGAs have largely superseded such devices for new designs, understanding this PLD provides critical insight into the evolution of programmable logic and it remains a relevant component for maintaining and repairing legacy electronic systems.

Keywords: Programmable Logic Device (PLD), Electrically Erasable CMOS, Output Logic Macrocell (OLMC), 5V Operation, 15ns Propagation Delay.