MAX3244CWI+

Overview

The MAX3244CWI+ is a low-power RS-232 transceiver manufactured by Analog Devices Inc./Maxim Integrated. It features three drivers and five receivers, supporting full-duplex communication at a guaranteed data rate of 250kbps. 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 dual charge pumps requiring four 0.1μF external capacitors. ESD protection is rated at ±15kV (Air-Gap), ±8kV (Contact), and ±15kV (Human Body Model). The component is housed in a 28-pin Wide SOIC package and supports an operating temperature range from -40°C to +85°C.

Feature Summary

• AutoShutdown Plus functionality 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.
• Enhanced electrostatic discharge protection ensures robustness against high-voltage static events.
• Dedicated INVALID output pin indicates the presence of valid RS-232 signal levels.

Applications

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

Procurement Notes

Verify the specific suffix 'C' for commercial temperature range (-40°C to +85°C) against the datasheet selector guide. Confirm the 'W' suffix corresponds to the 28-pin Wide SOIC package. Ensure the '+' suffix denotes lead-free/RoHS compliance status as defined by the manufacturer's ordering information.

Selection Notes

Select this part for applications requiring multiple receiver lines and moderate data rates up to 250kbps. It is suitable for space-constrained designs due to the minimal external capacitor requirement. Consider the MAX3245E variant if higher speed operation up to 1Mbps is required for the same package configuration.

Part Context

This component belongs to the MAX3224E/MAX3225E/MAX3226E/MAX3227E/MAX3244E/MAX3245E family. These devices are designed for EIA/TIA-232 and V.28/V.24 communications interfaces. The family shares common features such as low-power operation and high ESD protection, with variations primarily in driver/receiver counts and maximum data rates.

Replacement Considerations

The MAX3245EEWI+ serves as a direct functional substitute within the same series, offering identical pinout and features but with a guaranteed data rate of 1Mbps instead of 250kbps.

FAQ

How does the AutoShutdown Plus feature function?

It automatically shuts down the charge pumps and disables transmitters when no valid signal transition is detected on any input for more than 30 seconds, reducing supply current to approximately 1μA. The device wakes up upon sensing a valid transition.

What is the purpose of the INVALID output?

The INVALID output goes low when no valid RS-232 voltage levels are detected on all receiver inputs. It indicates the physical layer connection status and remains independent of the FORCEON and FORCEOFF control states.

What external components are required for operation?

The device requires four external capacitors for its dual charge pump. For a 3.3V supply, four 0.1μF capacitors are typically used. For a 5.0V supply, one 0.047μF capacitor and three 0.33μF capacitors are specified.