MAX3318ECUP+

Overview

The MAX3318ECUP+ is a dual-transmitter, dual-receiver RS-232-compatible transceiver manufactured by Analog Devices Inc. (Maxim Integrated). It operates on a single +2.25V to +3.0V supply and utilizes an internal dual charge pump to generate the required voltage levels. The device supports data rates up to 460kbps with a guaranteed slew rate of 4V/µs. It features AutoShutdown Plus technology, reducing supply current to 1µA when inputs are inactive for over 30 seconds. The component includes a READY output indicating charge pump regulation status and INVALID logic for signal detection. It is housed in a 20-pin TSSOP package and rated for operation from -40°C to +85°C.

Feature Summary

• AutoShutdown Plus functionality automatically reduces power consumption during periods of inactivity without requiring BIOS modifications.
• Integrated dual charge pump enables full RS-232 compatibility using only four small capacitors within a low-voltage operating range.
• Provides a READY output pin that signals when the internal charge pumps are regulating and the device is prepared for transmission.

Applications

• Palmtop Computers
• Hand-Held Instruments
• GPS Systems

Procurement Notes

Verify the specific suffix 'EUP+' against the manufacturer's official ordering guide to confirm the industrial temperature range (-40°C to +85°C) and the 20-pin TSSOP packaging configuration. Ensure the procurement channel sources directly from authorized distributors to guarantee authenticity and compliance with RoHS standards.

Selection Notes

Select this component for applications requiring minimal external capacitance and ultra-low standby power in portable devices. It is suitable for systems powered by a single 2.5V source where automatic power management is critical. Verify that the system UART can tolerate the 30-second inactivity threshold before entering shutdown mode.

Part Context

This part belongs to the MAX3316–MAX3319 family of 2.5V RS-232 transceivers. While sharing similar electrical characteristics and pinouts, the MAX3318 specifically provides two transmitters and two receivers with AutoShutdown Plus capabilities, distinguishing it from the single-channel MAX3319 and the manually controlled MAX3317.

Replacement Considerations

The TI TRS3318E is documented as having the same functionality and pinout as the MAX3318E. Cross-reference the TRS3318E datasheet to verify parameter alignment before implementation.

FAQ

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

The device enters AutoShutdown Plus mode if FORCEOFF is high, FORCEON is low, and no valid signal transition is detected on any receiver or transmitter input for more than 30 seconds.

What is the function of the INVALID output pin?

The INVALID output asserts low when no valid RS-232 voltage levels have been detected on all receiver inputs, indicating the receiver's input condition regardless of FORCEON or FORCEOFF states.

Can unused transmitter inputs be left floating?

No, the transmitter inputs do not have internal pullup resistors. Unused inputs must be connected to GND or VCC to prevent undefined states.