1 Introduction

The LM5171 is a dual channel interleaved bidirectional (buck or boost) controller utilizing average current mode control. Precise current sense amplifiers are integrated for precise current regulation. The robust 5A half-bridge gate drivers can drive high power MOSFETs. The controller can be dynamically programmed to operate in either the diode emulation mode (DEM) or forced pulse width modulation mode (FPWM). Two error amplifiers, a 3.5V voltage reference (VREF) and 5V bias supplies (VDD) are integrated. Versatile protection features include cycle-by-cycle current limiting, overvoltage protection (OVP), over temperature protection and urgent shutdown latch. The I²C interface supports monitoring and diagnosis during operation.

Average current mode control gives the benefit to regulating the average inductor current precisely. Constant current operation can be obtained by controlling ISET1 and ISET2 (ISETx) voltage. In multiphase operation, current sharing is achieved by connecting ISETx pins together.

The LM5171 supports independent channel operation. Each channel has dedicated DIRx, ISETx, ENx, SS/DEMx pins to fulfill independent control. The two channels of LM5171 can be configured as dual buck, dual boost or even one buck with one boost. It is possible to build two independent CC/CV battery chargers with a single LM5171. Also, it is possible to achieve bidirectional buck-boost conversion with a single LM5171: a boost converter cascaded by a buck converter. The block diagram of the two-stage converter is shown in Figure 1-1.