MAX3380ECUP+T

Overview

The MAX3380ECUP+T is a +2.35V to +5.5V RS-232 transceiver featuring two receivers and two transmitters in a 20-pin TSSOP package. It supports data rates up to 460kbps with ±15kV ESD protection on all I/Os. The device operates from a single supply voltage and includes an AutoShutdown Plus feature that reduces supply current to 1µA when idle. A dedicated VL pin allows logic level compatibility down to +1.65V.

Feature Summary

• AutoShutdown Plus technology automatically enters a low-power shutdown mode after 30 seconds of inactivity, reducing supply current to 1µA.
• Integrated dual-mode regulated charge pump enables true RS-232 performance across the entire lithium-ion battery range without increasing supply current at lower voltages.
• Provides ±15kV electrostatic discharge (ESD) protection on all CMOS and RS-232 inputs and outputs using Human Body Model and IEC 1000-4-2 standards.
• Features a separate VL logic supply input that sets receiver output levels and transmitter thresholds, enabling interoperation in mixed-logic voltage systems down to +1.65V.

Applications

• Cell phone data lump cables
• PDA data lump cables
• GPS receivers
• Digital cameras

Procurement Notes

Verify the specific suffix 'C' indicates a commercial temperature range of 0°C to +70°C, while 'E' denotes industrial range (-40°C to +85°C). Confirm RoHS compliance status for the '+T' tape-and-reel packaging variant. Cross-reference the exact ordering number against manufacturer documentation to ensure correct pinout and electrical specifications before integration.

Selection Notes

Select this component for applications requiring high-speed RS-232 communication up to 460kbps within portable devices powered by lithium-ion batteries. The unique VL pin is essential for interfacing with microcontrollers operating at logic levels below the main VCC supply. Ensure adequate decoupling capacitors are used for the charge pump to maintain signal integrity at maximum data rates.

Part Context

This part belongs to the MAX3380E/MAX3381E family of low-voltage RS-232 transceivers. The MAX3380E variant specifically supports higher data rates compared to the MAX3381E. Both share identical pinouts and core features, differing primarily in guaranteed baud rate capabilities and slew rate characteristics for noise reduction.

Replacement Considerations

MAX3381ECUP+T offers similar functionality but with a reduced maximum data rate of 250kbps and slower slew rates for EMI-sensitive environments. Verify if the application requires the full 460kbps throughput or if the lower speed variant provides sufficient performance for cost optimization.

FAQ

How does the AutoShutdown Plus feature function?

The AutoShutdown Plus circuitry monitors receiver and transmitter inputs. If no valid signal transition is detected for 30 seconds, the internal charge pumps and drivers shut down, reducing supply current to 1µA. The device wakes up immediately upon detecting a valid edge.

What is the purpose of the VL pin?

The VL pin serves as a separate logic supply input that sets the threshold for transmitter inputs and the output voltage levels for receivers and the INVALID pin. This allows the device to interface with host logic supplies ranging from +1.65V to +5.5V independently of the main VCC supply.

How does the charge pump handle varying supply voltages?

The dual-mode charge pump adjusts its output based on VCC. Above +3.7V, it generates ±5.5V for RS-232 compliance. Below +3.1V, it switches to generate ±4.0V for RS-232 compatibility, maintaining operation throughout the lithium-ion battery discharge curve without increased current consumption.