8412901XA

Overview

The TIBPAL20L8-20M is a high-performance programmable array logic device utilizing IMPACT/thin technology. It features a maximum frequency of 41.6 MHz without feedback and 40 MHz with feedback. The supply voltage ranges from 4.5 V to 5.5 V, with a typical operating current of 180 mA. Propagation delays are typically 20 ns for I/O paths and 15 ns for clock-to-Q transitions. The device supports an operating temperature range of -55°C to 125°C.

Feature Summary

• Combines Advanced Low-Power Schottky technology with titanium-tungsten fuses for reliable performance.
• Provides preload capability on output registers to simplify testing by setting initial states.
• Includes power-up clear functionality where all registered outputs initialize to a low state upon power application.

Applications

• Custom function design requiring compact circuit board implementation.
• State-machine initialization and testing sequences.
• High-speed digital logic replacement for conventional TTL circuits.

Procurement Notes

Verify the specific package variant (FK or JT) against the required pinout diagram, as pin assignments differ between plastic and ceramic carriers. Confirm that the programming equipment supports the titanium-tungsten fuse architecture. Ensure the system design accounts for the specified 180 mA maximum supply current during operation.

Selection Notes

Select this device when military-grade temperature stability (-55°C to 125°C) is required alongside high-speed PAL functionality. The L8 suffix indicates a purely combinational logic structure without registered outputs. Compare propagation delay specifications against system timing constraints to ensure compatibility with existing clock frequencies.

Part Context

This component belongs to the TIBPAL20 series of high-performance IMPACT PAL circuits. It serves as a functional substitute for older PAL20L8 devices but offers improved speed characteristics. The 'M' suffix denotes the military temperature range variant, distinguishing it from the commercial 'C' series which operates from 0°C to 75°C.

Replacement Considerations

The datasheet explicitly states these devices are functionally equivalent but faster than PAL20L8, PAL20R4, PAL20R6, and PAL20R8. Verify that the target application does not require the registered outputs found in the R-series variants if replacing a non-registered design.

FAQ

How are the output registers preloaded?

Registers are preloaded individually by raising Pin 13 to VIHH, applying the desired data level to the corresponding output pin, pulsing Pin 1 to clock the data, and then lowering Pin 13 back to VIL.

What happens to the registers immediately after power-up?

Following power-up, all registers are reset to zero. This feature simplifies state-machine initialization, provided the VCC rise is monotonic and setup times are met before the first clock transition.

Does the maximum frequency apply to all configurations?

No. The maximum frequency of 41.6 MHz applies to the registered variants (TIBPAL20R') without feedback. The TIBPAL20L8 variant does not have a defined fmax because it lacks registered outputs and clock inputs.