PCF8579HT/1

Overview

The PCF8579HT/1 is a low-power CMOS LCD column driver designed for driving multiplexed dot-matrix displays with rates of 1:8, 1:16, 1:24, or 1:32. It provides 40 outputs to drive a 32 x 40 point matrix and includes 1280-bit RAM for display data storage. The device communicates via an I²C bus and supports cascading up to 16 units on a single bus using two slave addresses. It operates with a logic supply voltage range of 2.5 V to 6 V and a maximum LCD supply voltage of 9 V.

Feature Summary

• Functions as a dedicated column driver that pairs with the PCF8578 row driver to form a comprehensive LCD dot-matrix driver chipset capable of driving large displays.
• Features internal display RAM with automatic incrementing addressing and display bank switching to minimize communication overhead during data loading.
• Supports external selectable bias configurations and allows partial VDD shutdown through specific ESD protection design on SCL and SDA pins.

Applications

• Automotive information systems
• Telecommunication equipment
• Point-of-sale (POS) terminals
• Industrial computer terminals
• Instrumentation devices

Procurement Notes

Verify the complete part number including the suffix, as variations exist for different package types such as TQFP64 or VSO56. Confirm availability status, as this component may be listed as discontinued or in sample stages depending on the current inventory cycle. Ensure the selected variant matches the required pin configuration and thermal specifications for the target application environment.

Selection Notes

Select this component when designing systems requiring high-density LCD column driving with minimal microcontroller intervention. It is specifically intended to work in conjunction with the PCF8578 row driver to handle complex multiplexing ratios. Consider its I²C interface compatibility and power consumption characteristics relative to the system's voltage constraints and display size requirements.

Part Context

This device belongs to NXP's family of low-power CMOS LCD drivers. It is engineered to complement the PCF8578 row driver, creating a scalable solution for driving extensive dot-matrix displays. Together, these components can manage displays with up to 40,960 points, offering a flexible architecture for various graphical interface needs.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Verify if the PCF8579T variant offers identical functionality within the same package constraints before considering alternative sourcing options.

FAQ

How does the PCF8579HT/1 handle display data updates?

It utilizes 1280-bit RAM with automatic incrementing addressing and display bank switching to reduce communication overhead when updating the display content.

What is the maximum number of devices that can be cascaded?

Up to 16 PCF8579 devices can be cascaded, allowing a total of 32 devices on the same I²C bus by utilizing two distinct slave addresses.