The ADP1974 is a constant frequency， voltage mode， synchronous， pulse-width modulation （PWM） controller for bidirectional dc-todc applications. The ADP1974 is designed for use in battery testing， formation， and conditioning applications with an external， high voltage field effect transistor （FET） half bridge driver， and an external control device such as the AD8450/AD8451. The device operates as a buck converter in battery charge mode and as a boost converter in discharge mode to recycle energy to the input bus. The ADP1974 high voltage VIN supply pin can withstand a maximum operating voltage of 60 V and reduces the need for additional system supply voltages. The ADP1974 has integrated features such as precision enable， internal and external synchronization control with programmable phase shift， programmable maximum duty cycle， dead time control， and peak hiccup current-limit protection. Additional protection features include soft start to limit input inrush current during startup， precision enable， and thermal shutdown （TSD）。 The ADP1974 also has a COMP pin to provide external control of the PWM duty cycle and a FAULT pin that can disable the DH and DL outputs. These functions are compatible with the AD8450/AD8451 analog front-end （AFE） error amplifiers. The ADP1974 is available in a 16-lead TSSOP package and is pin-compatible with the ADP1972