MAX3226ECAE+T

Overview

The MAX3226ECAE+T is a single-driver, single-receiver RS-232 transceiver from the MAX3224–MAX3227 family. It operates on a +3.0V to +5.5V supply and guarantees a maximum data rate of 250kbps. The device features AutoShutdown Plus technology, reducing supply current to 1µA when inputs are inactive for over 30 seconds. It includes an INVALID output for signal detection and a READY output indicating charge pump regulation. The component utilizes a dual charge pump requiring four 0.1µF capacitors at 3.3V. It is housed in a 16-pin SSOP package and supports an operating temperature range of -40°C to +85°C.

Feature Summary

• AutoShutdown Plus functionality automatically reduces power consumption by disabling internal charge pumps during periods of inactivity.
• Integrated INVALID logic output detects valid RS-232 voltage levels on receiver inputs independent of shutdown states.
• READY output pin asserts high to indicate that the internal charge pumps are regulating and the device is ready for transmission.
• Proprietary low-dropout transmitter stage ensures true RS-232 performance across the full supply voltage range.

Applications

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

Procurement Notes

Verify the specific suffix 'E' confirms the industrial temperature range (-40°C to +85°C) and 'AE' denotes the SSOP-16 package. Confirm '+T' indicates tape-and-reel packaging if required for automated assembly. Ensure the source document explicitly lists this exact part number variant to avoid confusion with similar models like the MAX3227 or MAX3244.

Selection Notes

Select this component for applications requiring a single-channel RS-232 interface with ultra-low standby power. It is suitable for battery-operated systems where automatic power saving is critical. Choose this model over the MAX3227 if a guaranteed 1Mbps data rate is not required, as this part is optimized for 250kbps operation. Verify capacitor requirements match the target supply voltage.

Part Context

This device belongs to the MAX3224–MAX3227/MAX3244/MAX3245 series of 3V-powered EIA/TIA-232 interfaces. While the MAX3227 offers 1Mbps speeds, the MAX3226 is rated for 250kbps. Both share the same AutoShutdown Plus architecture and physical footprint. The series is designed to replace traditional RS-232 drivers in space-constrained portable electronics.

Replacement Considerations

The MAX3227EEAE+T serves as a direct functional substitute within the same package, offering increased speed up to 1Mbps while maintaining identical pinouts and power management features.

FAQ

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

The device enters shutdown mode when no valid signal transition is sensed on any receiver or transmitter input for more than 30 seconds. It wakes up upon detecting a valid transition.

What is the function of the INVALID output pin?

The INVALID output goes low when no valid RS-232 voltage levels are detected on all receiver inputs. It remains active regardless of the FORCEON or FORCEOFF states.

What external components are required for the charge pump?

The device requires four small capacitors (C1–C4). For a 3.3V supply, four 0.1µF capacitors are sufficient. Higher voltages may require larger values as specified in the datasheet.