MAX3225ECUP+T

Overview

The MAX3225ECUP+T is a dual RS-232 transceiver manufactured by Analog Devices Inc./Maxim Integrated, housed in a 20-pin TSSOP package. It operates on a single +3.0V to +5.5V supply and achieves a typical supply current of 1μA through AutoShutdown Plus technology. The device guarantees a data rate of 1Mbps and includes two drivers and two receivers for full-duplex communication. It features ±15kV ESD protection across all transmitter outputs and receiver inputs. Internal dual charge pumps generate the necessary voltage levels using only four external 0.1μF capacitors.

Feature Summary

• AutoShutdown Plus functionality automatically reduces power consumption when the interface is idle or disconnected.
• Integrated dual charge pump generates required internal voltages without requiring external inductors.
• Enhanced electrostatic discharge protection ensures robustness against high-voltage static events.
• MegaBaud operation capability supports high-speed serial communication applications.

Applications

• Notebook, Subnotebook, and Palmtop Computers
• Cellular Phones and Battery-Powered Equipment
• Hand-Held Equipment and Peripherals
• Printers and Automotive Systems

Procurement Notes

Verify the specific suffix 'T' indicates tape-and-reel packaging configuration during procurement. Confirm that the component meets lead-free and RoHS compliance standards as indicated by the '+' designation. Ensure the ordering information matches the exact temperature range and package dimensions required for the target design implementation.

Selection Notes

Select this model when a guaranteed 1Mbps data rate is required for RS-232 interfaces. Choose this part over lower-speed variants if high-speed modem communication is necessary. Verify that the system can accommodate the required four external capacitors for the charge pump circuitry before finalizing the selection.

Part Context

This component belongs to the MAX3224E/MAX3225E/MAX3226E/MAX3227E family of low-power RS-232 transceivers. It shares core architectural features with siblings like the MAX3224E but differs in its maximum guaranteed data rate specification. The family utilizes Maxim's proprietary AutoShutdown Plus technology to optimize battery life in portable devices.

Replacement Considerations

MAX3225ECUP+ serves as the non-tape reel equivalent. MAX3227ECUP+ offers identical functionality but with a single driver and receiver configuration instead of dual channels.

FAQ

How does the AutoShutdown Plus feature determine when to enter low-power mode?

The device enters shutdown mode when valid signal transitions are not detected on any receiver or transmitter input for more than 30 seconds, typically occurring when the cable is disconnected or peripherals are inactive.

What is the function of the READY output pin?

The READY output asserts high when the internal charge pumps are regulating and the device has reached sufficient voltage levels to begin transmitting RS-232 signals reliably.

Can unused transmitter inputs be left floating?

No, unused transmitter inputs should be connected to either ground (GND) or the supply voltage (VCC) to prevent undefined states, as the inputs do not have internal pull-up resistors.