ISL83385IA

Overview

The ISL83385IA is a low-power RS-232 transceiver manufactured by Intersil, designed for portable and battery-operated applications. It operates on a single +3V to +5.5V supply and features integrated charge pumps requiring only four external 0.1µF capacitors. The device provides three drivers and five receivers, ensuring compatibility with EIA/TIA-232 and V.28/V.24 specifications even at 3.0V. Key electrical parameters include a guaranteed data rate of 250kbps, a slew rate of 6V/µs, and ±15kV IEC 61000 ESD protection on RS-232 I/O pins. Supply current is typically 0.3mA in active mode and drops below 1µA in powerdown state.

Feature Summary

• Integrated manual powerdown function reduces standby supply current to a 1µA trickle
• On-chip voltage converters require only four small, low-value external capacitors
• Receiver hysteresis provides improved noise immunity for reliable signal detection
• Single SHDN pin allows disabling of transmitters while keeping receivers active

Applications

• Personal Digital Assistants (PDAs) and Palmtops
• Notebook and laptop computers
• Battery-powered industrial handheld devices

Procurement Notes

Verify the manufacturer designation carefully, as Intersil was acquired by Renesas Electronics. Confirm that the specific suffix 'IA' corresponds to the intended temperature range and package variant in the official datasheet. Ensure compliance with current RoHS directives and lead-free manufacturing standards required for modern assembly processes.

Selection Notes

Select this component when low power consumption is critical for portable systems. It serves as a pin-compatible upgrade for older MAX3385E designs. Verify that the system voltage falls within the 3.0V to 5.5V range. Consider the 250kbps data rate limit; higher speeds require different transceivers. Check if the ±15kV ESD rating meets the environmental requirements of the deployment site.

Part Context

This part belongs to the ISL8338xE family of low-power RS-232 transceivers. It shares functional similarities with other Intersil parts like the ISL83387 but differs in driver/receiver counts and specific power management features. The family is characterized by its ability to operate at lower voltages than traditional RS-232 chips without external negative voltage generation.

Replacement Considerations

Officially documented pin-compatible replacements include the MAX3385E from Maxim Integrated. Other compatible alternatives may exist from manufacturers producing equivalent low-power RS-232 transceivers, provided they match the 3V-5.5V supply range and 250kbps speed.