An interface for improving RF power efficiency

Quick Facts

Fundamental Features
  • Analog differential interface
  • Bandwidth greater than 18MHz for LTE20 support
Physical Layer

Analog, differential and unidirectional voltage mode interface

Use Cases

Cellular 3G or LTE radio transmitters in any connected device


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The MIPI Envelope Tracking Interface provides a point-to-point interface between a radio transmitter and an envelope tracking power supply (ETPS). The specification enables mobile device manufacturers to deploy envelope tracking technology in radio transmitter.

Envelope tracking is used to reduce power consumption of the RF power amplifier, which in turn improves the efficiency of the transmitter. Envelope tracking is particularly important when a device is transmitting at a high data rate on 4G and other cellular standards that use advanced modulation schemes, a standard feature in LTE.

The MIPI eTrakSM Envelope Tracking Interface facilitates interoperability between transmitters and the ETPS to provide flexibility in selecting components, streamline development and lower development costs. The specification provides a high-speed, unidirectional analog differential interface that includes a low-power PHY. It provides bandwidth to support LTE operation at 20 MHz.

The MIPI Envelope Tracking Interface is developed by the MIPI Alliance Analog Control Interface Working Group. The current release, v.1.1, was released in September 2014.

Note: The specification is available only to MIPI Alliance members. For information about joining MIPI Alliance, visit Join MIPI.

Get the Specification

MIPI eTrak℠ v1.1
Member version

See also: App Note


Current Version: 

v1.1 (September 2014)