Parallel-Form Switch-Linear Hybrid Envelope Tracking Power Supply with Adaptive Hysteresis Current Control

The parallel-form switch-linear hybrid (SLH) envelope tracking (ET) power supply is typically composed of a buck converter and a Class AB linear amplifier connected in parallel, featuring simple structure and high efficiency. However, when the load voltage swing is large, the loss of the linear amplifier is large, leading to decreased overall efficiency. For addressing this problem, this paper proposes an adaptive hysteresis current control, to optimize the operation of the power devices of linear amplifier, letting them operate in higher and lower output power regions, respectively, thus reducing the voltage across them. To verify the effectiveness of the proposed method, a simulation platform is established for tracking 5-MHz envelope signal with 10-V ~ 27-V output voltage. The results validated the proposed method.