ICL3237IAZ-T

Overview

The ICL3237IAZ-T is a low-power RS-232 transceiver manufactured by Renesas Electronics Corporation, operating from a single +3V to +5.5V supply. It integrates five drivers and three receivers, along with a noninverting monitor receiver for wake-up capability. The device meets EIA/TIA-232 and V.28/V.24 specifications at 3.0V. It features manual powerdown functionality that reduces standby current to 1µA. Data rates are selectable via the MBAUD pin, supporting 250kbps or 1Mbps. The component utilizes on-chip charge pumps requiring only four external capacitors and provides ±15kV ESD protection.

Feature Summary

• Integrates five drivers and three receivers with a dedicated always-active monitor receiver for system wake-up capabilities.
• Features manual powerdown control that significantly reduces standby supply current to 1µA for battery-powered applications.
• Includes on-chip regulated dual charge pumps that generate ±5.5V transmitter supplies using only four small external capacitors.
• Provides ±15kV ESD protection on RS-232 pins and incorporates receiver hysteresis to improve noise immunity.

Applications

• Battery powered, hand-held, and portable equipment
• Laptop computers, notebooks, and palmtops
• Cellular and mobile phones
• Modems, printers, and digital camera peripherals

Procurement Notes

Verify the specific ordering suffix '-T' confirms tape and reel packaging rather than tube. Confirm the 'I' suffix indicates the industrial temperature range of -40°C to +85°C. Ensure the RoHS compliant Pb-free plus anneal material set matches your soldering process requirements. Check moisture sensitivity level classifications before storage and reflow.

Selection Notes

Select this component when a high channel count (5Tx/3Rx) is required in a compact SSOP package. The manual powerdown feature is suitable for systems where software controls sleep states. Verify the MBAUD pin configuration aligns with the target data rate requirements of 250kbps or 1Mbps. Ensure the external capacitor values match the specific VCC voltage to maintain charge pump stability.

Part Context

This part belongs to the Intersil ICL32XX family of 3V RS-232 transceivers designed for low power consumption. It serves as a drop-in replacement for older 5V RS-232 devices like the MAX3237. The device is part of a broader portfolio including variants with automatic powerdown or different driver/receiver counts.

Replacement Considerations

The datasheet identifies the ICL3237 as a direct drop-in replacement for the MAX3237. Verify pinout compatibility and electrical specifications against existing designs before substitution.

FAQ

How is the data rate selected on the ICL3237?

The data rate is selected via the MBAUD pin. Driving MBAUD low selects the 250kbps rate, while driving it high selects the 1Mbps rate.

What is the function of the ROUTB pin?

ROUTB is a noninverting, always-active monitor receiver output. It remains enabled during manual powerdown and standard receiver disable states, making it useful for ring indicator monitoring.

How does the manual powerdown mode affect the charge pumps?

When the SHDN pin is driven low, the device enters powerdown mode. The on-chip charge pumps turn off, causing V+ to collapse to VCC and V- to collapse to GND, reducing supply current to 1µA.