MAX3245ECUI+

Overview

The MAX3245ECUI+T is a true RS-232 transceiver manufactured by Analog Devices (Maxim Integrated). It features three drivers and five receivers, supporting data rates up to 1Mbps. The device operates on a single +3.0V to +5.5V supply and achieves a typical supply current of 1μA through AutoShutdown Plus technology. It includes ±15kV ESD protection on all inputs and outputs. The EC suffix indicates an industrial temperature range of 0°C to +70°C, and the U package denotes a 28-pin TSSOP form factor.

Feature Summary

• AutoShutdown Plus technology automatically reduces power consumption when the interface is idle or disconnected.
• Integrated dual charge pump generates internal voltage rails using only four small external capacitors.
• High electrostatic discharge protection ensures robustness against air-gap and contact discharges.
• Dedicated INVALID output pin provides real-time status regarding valid RS-232 signal presence.

Applications

• Notebook, subnotebook, and palmtop computers
• Cellular phones and battery-powered equipment
• Hand-held devices and peripherals
• Printers and automotive systems

Procurement Notes

Verify that the specific ordering suffix matches the required thermal and packaging specifications. The 'E' designation confirms operation within the 0°C to +70°C industrial range, while the 'U' code specifies the 28-TSSOP package. Confirm the '+T' suffix aligns with tape-and-reel delivery requirements for automated assembly processes.

Selection Notes

Select this component when designing high-speed serial interfaces requiring 1Mbps throughput under low-voltage conditions. The inclusion of five receiver channels makes it suitable for complex DTE applications like PCs. Ensure the design accommodates the four 0.1μF capacitors necessary for the internal charge pump operation.

Part Context

This part belongs to the MAX32xxE family of 3V RS-232 transceivers. It shares core architecture with the MAX3244E but offers higher speed capabilities. The series is designed to replace legacy 5V components in modern portable electronics where power efficiency and compact footprints are critical constraints.

Replacement Considerations

The MAX3245EEUI+T serves as a direct replacement for units requiring the same functionality but operating across the extended -40°C to +85°C temperature range. Verify that the system's thermal environment remains within the 0°C to +70°C limits specified for the EC variant.

FAQ

How does the AutoShutdown Plus feature function?

It monitors transmitter and receiver inputs. If no activity is detected for over 30 seconds, the device enters a low-power shutdown mode drawing approximately 1μA. It wakes up immediately upon sensing a valid signal transition.

What is the purpose of the R2OUTB pin?

R2OUTB is a noninverting complementary receiver output that remains active even during shutdown. It allows monitoring of ring indicator signals without creating current paths through other connected devices.

Why are four external capacitors required?

The device uses a proprietary dual charge pump to generate the necessary positive and negative voltage rails from a single supply. Four small 0.1μF capacitors are sufficient to support this operation at 3.3V.