The LM5170 controller provides the essential high voltage and precision elements of adual-channel bidirectional converter. It regulates the average current flowing between the highvoltage and low voltage ports in the direction designated by the DIR input signal. The currentregulation level is programmed through analog or digital PWM inputs.
Dual-channel differential current sense amplifiers and dedicated channel current monitorsachieve typical current accuracy of 1%. Robust 5-A half-bridge gate drivers are capable of drivingparallel MOSFET switches delivering 500 W or more per channel. The diode emulation mode of thesynchronous rectifiers prevents negative currents but also enables discontinuous mode operation forimproved efficiency with light loads. Versatile protection features include cycle-by-cycle currentlimiting, overvoltage protection at both HV and LV ports, MOSFET failure detection, andovertemperature protection.
An innovative average current mode control scheme maintains constant loop gain allowing asingle R-C network to compensate both buck and boost conversion. The oscillator is adjustable up to500 kHz and can synchronize to an external clock. Multiphase parallel operation is achieved byconnecting two LM5170 controllers for 3- or 4-phase operation, or by synchronizing multiplecontrollers to phase-shifted clocks for a higher number of phases. A low state on the UVLO pindisables the LM5170 in a low current shutdown mode.