MAX3243ECWI

Overview

The MAX3243ECWI is a Maxim Integrated RS-232 transceiver featuring three drivers and five receivers. It operates from a +3.0V to +5.5V supply with a typical operating current of 1µA in shutdown mode. The device supports data rates up to 250kbps and includes AutoShutdown functionality. It provides ±15kV ESD protection on all I/O pins. The component is housed in a 28-pin TSSOP package and functions within a temperature range of 0°C to +70°C.

Feature Summary

• AutoShutdown technology reduces power consumption by disabling the charge pump and drivers when no valid RS-232 signal is detected.
• Integrated dual charge pumps generate internal ±5.5V supplies using only four small external capacitors.
• Includes an always-active complementary receiver output (R2OUTB) for monitoring peripherals during system shutdown.

Applications

• Notebook, subnotebook, and palmtop computers
• Battery-powered equipment and handheld devices
• Cellular phones and peripherals

Procurement Notes

Verify the specific suffix 'CWI' against the manufacturer's official datasheet to confirm the 28-pin TSSOP package and commercial temperature range. Ensure compatibility with existing BIOS or operating systems as the AutoShutdown feature requires no software changes. Confirm RoHS compliance status for the specific manufacturing lot.

Selection Notes

Select this part for applications requiring low-voltage operation down to 3.0V and minimal standby power consumption. The 3-driver/5-receiver configuration is suitable for complex serial port implementations. Verify that the required data rate does not exceed 250kbps and that the system can accommodate the necessary external charge-pump capacitors.

Part Context

This component belongs to the MAX3221E/MAX3223E/MAX3243E family of low-power RS-232 transceivers. It shares core features such as AutoShutdown and high ESD protection with its siblings but offers a higher channel count. The ECWI variant specifically denotes the commercial temperature grade and surface-mount packaging.

Replacement Considerations

MAX3243EEAI+T: Analog Devices / Maxim Integrated; SSOP-28 package, -40°C to +85°C temperature range.

FAQ

How does the AutoShutdown feature function?

When FORCEON is low and FORCEOFF is high, the device monitors receiver inputs. If no valid RS-32 levels are detected for 30µs, the charge pump and drivers shut off, reducing supply current to 1µA.

What is the purpose of the R2OUTB pin?

R2OUTB is an always-active noninverting complementary receiver output. It allows external devices to be monitored without forward biasing protection diodes in circuitry that may be powered down.

Can the MAX3243ECWI drive serial mice?

Yes, the MAX3243E series is designed to drive serial mice. However, AutoShutdown must be disabled by connecting FORCEOFF and FORCEON to VCC to ensure continuous operation.