LM8322JGR8X/NOPB

Specialized Overview

The LM8322JGR8X/NOPB is a Mobile I/O Companion IC designed to offload host processors from keypad scanning tasks. It supports matrix-addressed keypads up to 8x12 keys plus 8 special-function keys, totaling 104 keys. The device features an I2C-compatible ACCESS.bus interface operating in slave mode at Fast-mode speeds up to 400 kHz. It includes three host-programmable PWM outputs for LED brightness modulation and general-purpose I/O expansion on unused pins. A FIFO buffer stores up to 15 key events, signaling the host via an IRQ output. The component operates within a temperature range of -40°C to +85°C and is housed in a 36-pin Micro-Array package.

Specialized Feature Summary

• Supports large keypad matrices with dedicated special-function keys that pull scan inputs directly to ground.
• Integrates a hardware FIFO buffer to store multiple key events before host retrieval.
• Provides programmable PWM outputs capable of smooth LED brightness modulation with ramp control.
• Enables wake-up from Halt mode triggered by key-scan events or ACCESS.bus activity.

Specialized Applications

• Mobile phones
• Personal Digital Assistants (PDAs)
• Smart handheld devices
• Personal media players

Specialized Procurement Notes

Verify the obsolete status of this component prior to design implementation. Confirm that the 36-pin Micro-Array package GRA36A matches your PCB footprint requirements. Ensure the -40 to +85°C industrial temperature rating aligns with your environmental specifications. Check for available replacement components if long-term supply is required.

Specialized Selection Notes

Select this component when a host processor requires dedicated hardware handling for matrix keypads exceeding standard GPIO capabilities. It is suitable for designs needing integrated PWM for display backlighting alongside input expansion. Verify that the ACCESS.bus interface compatibility meets the system's communication protocol needs. Consider the 36-pin package density for compact mobile form factors.

Specialized Part Context

The LM8322 was developed by National Semiconductor, which was subsequently acquired by Texas Instruments. It serves as a peripheral companion to main application processors in mobile electronics. The device simplifies system architecture by centralizing keypad scanning and basic I/O management functions.

Specialized Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Due to the obsolete status, alternative solutions must be sourced through current manufacturer catalogs or generic I/O expanders with similar interface protocols.