MAX3349EAEBE+T

Overview

The MAX3349EAEBE+T is a USB 2.0 full-speed transceiver with UART multiplexing mode, manufactured by Analog Devices Inc./Maxim Integrated. It provides a ±15kV ESD-protected interface for microprocessors or ASICs. The device supports enumeration, suspend, and VBUS detection. It operates in USB mode when VBUS is present (4.0V to 5.5V) and switches to UART mode otherwise. Key electrical parameters include a data rate of 12Mbps for USB and up to 921kbps for UART. Supply voltages are VL (1.4V to 2.75V), VUART (2.7V to 3.3V), and VBUS (4.0V to 5.5V). Operating temperature range is -40°C to +85°C. Package: 16-bump UCSP (2mm x 2mm).

Feature Summary

• Integrated ±15kV ESD protection on D+ and D- pins.
• UART multiplexing mode routes external UART signals to D+/D- for shared connector use.
• Internal linear regulator allows direct powering from the USB cable.
• Separate voltage input for UART transmitter/receiver (VUART).
• Built-in level shifting down to +1.4V for low-voltage ASIC compatibility.

Applications

• Cell Phones
• PDAs
• Digital Cameras

Procurement Notes

Verify the exact ordering suffix 'B16-1' corresponds to the 16-bump UCSP package configuration. Confirm RoHS compliance status as indicated by the '+' suffix. Ensure the component is sourced from authorized distributors to guarantee authenticity and traceability. Check for any specific handling requirements associated with the UCSP package type during assembly.

Selection Notes

Select this component when a mobile device requires a single connector for both USB and UART communication. It is suitable for applications needing low-voltage logic interfacing down to 1.4V. Consider the UCSP package size constraints. Verify that the system power supply can provide the required VBUS and VUART ranges. Ensure ESD protection requirements meet the ±15kV HBM standard.

Part Context

The MAX3349EA belongs to Maxim Integrated's family of USB transceivers designed for mobile devices. It integrates USB 2.0 full-speed functionality with a unique UART multiplexing capability. This integration reduces part count and cost by allowing a shared connector. The device simplifies design by eliminating the need for separate USB and UART interfaces in compact form factors.

Replacement Considerations

Check for other MAX3349 variants with different packages (e.g., TQFN) if pinout compatibility is not an issue. Verify functional equivalence regarding UART baud rates and ESD ratings. Ensure substitute components support the same voltage levels and operating temperature range.

FAQ

How does the MAX3349EA switch between USB and UART modes?

The device automatically switches modes based on the presence of VBUS. When VBUS exceeds the detection threshold, it enters USB mode. If VBUS is absent or below the threshold, it operates in UART mode.

What is the purpose of the ENUM pin?

The ENUM pin controls the internal 1.5kΩ pullup resistor on the D+ line. Driving it high connects the resistor to allow enumeration by a USB host, while driving it low disconnects it to logically disconnect the device.

Can the MAX3349EA be powered directly from a USB cable?

Yes, the device features an internal linear regulator that allows it to be powered directly from the VBUS line of a USB cable, generating the necessary VTRM voltage internally.