MAX3245CWI+

Overview

The MAX3245CWI+ is a true RS-232 transceiver manufactured by Analog Devices Inc./Maxim Integrated, housed in a 28-pin SOIC package. It operates on a single +3.0V to +5.5V supply and features three drivers and five receivers with full-duplex communication capability. The device guarantees a maximum data rate of 1Mbps using MegaBaud operation and incorporates AutoShutdown Plus technology to achieve a typical 1µA supply current during inactivity. It includes an INVALID output for signal detection and R2OUTB for continuous receiver monitoring. The component supports EIA/TIA-232 standards and functions within a commercial temperature range of 0°C to +70°C.

Feature Summary

• AutoShutdown Plus functionality automatically reduces power consumption when the interface is idle or disconnected.
• MegaBaud operation ensures reliable high-speed data transmission up to 1Mbps.
• Integrated dual charge pump generates required RS-232 voltage levels from a low-voltage single supply.
• INVALID output provides real-time status indication of valid RS-232 signal presence.

Applications

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

Procurement Notes

Verify the specific suffix 'C' indicates the commercial temperature range (0°C to +70°C) rather than the extended industrial range. Confirm the 'W' designation corresponds to the 28-pin SOIC package format. Ensure compatibility with existing BIOS configurations as the AutoShutdown Plus feature operates transparently without software modifications.

Selection Notes

Select this model for applications requiring 1Mbps data rates and low-power standby modes. The MAX3245 variant specifically supports higher speeds compared to the MAX3244. Consider the 28-pin SOIC package constraints for PCB layout. Verify that the system can tolerate the 100µs wake-up time associated with exiting the AutoShutdown Plus state.

Part Context

This component belongs to the MAX3224–MAX3227/MAX3244/MAX3245 family of RS-232 transceivers. It shares core architectural features such as the dual charge pump and AutoShutdown Plus logic with siblings like the MAX3244 and MAX3225. The primary distinction lies in its guaranteed 1Mbps data rate capability and specific pinout configuration for the 28-pin SOIC form factor.

Replacement Considerations

MAX3245EETX+T: Offers identical electrical performance but utilizes a TQFN-EP-36 package and supports an extended -40°C to +85°C temperature range.

FAQ

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

The device enters shutdown mode if no valid signal transition is 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 R2OUTB pin on the MAX3245?

R2OUTB is an always-active, noninverting complementary receiver output. It allows monitoring of receiver activity even when other receivers are in a high-impedance shutdown state, preventing forward biasing of connected devices.

Can the MAX3245CWI+ drive serial mice directly?

Yes, the MAX3245 is specifically designed and tested for mouse driveability, capable of powering serial mice from low-voltage supplies while maintaining RS-232 performance.