MAX3224CUP+

Overview

The MAX3224CUP+ is a dual RS-232 transceiver from Analog Devices/Maxim Integrated, housed in a 20-pin TSSOP package. It operates on a single +3.0V to +5.5V supply and achieves a typical shutdown current of 1µA via AutoShutdown Plus. The device guarantees a maximum data rate of 250kbps with two drivers and two receivers. Internal dual charge pumps generate ±5.5V using four external 0.1µF capacitors. Key control features include FORCEON, FORCEOFF, INVALID, and READY outputs for power management.

Feature Summary

• AutoShutdown Plus automatically reduces supply current to 1µA when the interface is idle or disconnected.
• Integrated dual charge pump generates required RS-232 voltages without external inductors.
• Logic-level READY output indicates when internal voltage regulators are active and ready for transmission.
• INVALID output detects valid RS-232 signal presence independent of shutdown states.

Applications

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

Procurement Notes

Verify the specific suffix 'CUP+' corresponds to the commercial temperature range (0°C to +70°C) and 20-TSSOP package. Confirm RoHS compliance status through official manufacturer documentation prior to integration.

Selection Notes

Select this component for applications requiring low-power standby modes in portable devices. Ensure the system design accommodates the 250kbps data rate limit, as higher speeds require alternative models within the family.

Part Context

This part belongs to the MAX3224–MAX3227/MAX3244/MAX3245 series of 3V-powered EIA/TIA-232 interfaces. The C-series designation specifically denotes the commercial operating temperature range, distinguishing it from the extended temperature E-series variants.

Replacement Considerations

The MAX3224EUP+ serves as the direct replacement for extended temperature operation (-40°C to +85°C). Other pin-compatible options include the MAX3225CUP+ for 1Mbps data rates.

FAQ

How does the AutoShutdown Plus feature function?

It monitors receiver and transmitter inputs; if no valid transitions occur for more than 30 seconds, the device shuts down to 1µA and wakes upon detecting a new edge.

What is the purpose of the INVALID output?

The INVALID output goes low when no valid RS-232 voltage levels are detected on any receiver input, indicating an inactive or disconnected cable state.

Can unused transmitter inputs be left floating?

No, unused transmitter inputs must be connected to GND or VCC to prevent undefined states and ensure proper shutdown behavior.