ICL3237IAZ

Overview

The ICL3237IAZ is a low-power RS-232 transceiver manufactured by Renesas Electronics, operating from a single +3V to +5.5V supply. It integrates five drivers and three receivers, featuring a noninverting monitor receiver for wake-up capability. The device supports selectable data rates of 250kbps or 1Mbps via the MBAUD pin. It includes manual powerdown functionality that reduces standby current to 1µA. ESD protection on RS-232 pins reaches ±15kV (Human Body Model). The component is housed in a 28-lead SSOP package and operates within an industrial temperature range of -40°C to +85°C.

Feature Summary

• Integrated charge pumps generate internal voltage supplies using only four external capacitors.
• Manual shutdown control minimizes power consumption for battery-operated applications.
• Noninverting monitor receiver remains active during shutdown to support peripheral wake-up functions.

Applications

• Battery-powered handheld devices such as PDAs and Palmtops
• Portable computing equipment including notebook and laptop computers
• Mobile communication hardware like cellular phones

Procurement Notes

Verify the specific suffix 'IAZ' confirms the industrial temperature grade (-40°C to +85°C) and lead-free RoHS compliance. Confirm the package type matches the required 28-lead SSOP footprint. Ensure moisture sensitivity level handling procedures are followed during assembly.

Selection Notes

Select this component when a system requires multiple serial ports with strict power constraints. The manual powerdown feature is essential for extending battery life in portable electronics. Verify that the application logic can manage the SHDN and EN pins to utilize the low-power modes effectively.

Part Context

This part belongs to the Intersil ICL32XX family of 3V RS-232 transceivers. It serves as a drop-in replacement for legacy 5V devices like the MAX3237. The ICL3237 variant specifically provides five drivers and three receivers, distinguishing it from lower-channel versions in the same series.

Replacement Considerations

The datasheet identifies the MAX3237 as a compatible predecessor. Verify that any substitute maintains the 28-lead SSOP form factor and supports the required 1Mbps data rate at 3V operation.

FAQ

How is the data rate selected?

The data rate is configured via the MBAUD pin. Connecting MBAUD to GND selects the 250kbps rate, while connecting it to VCC enables the 1Mbps MegaBaud mode.

What is the function of the R_OUTB pin?

R_OUTB is a noninverting monitor receiver output that remains active even when the standard receivers are disabled or the device is in powerdown mode, allowing for ring indicator monitoring.

How does the device handle unused transmitter inputs?

Unused transmitter inputs should be connected to GND to prevent them from floating, which could cause increased supply current and unintended signal transmission.