SLUSDL4 February 2020 TPS59632-Q1
PRODUCTION DATA
The TPS59632-Q1 device is a DCAP+ mode adaptive on-time controller. The DAC outputs a reference in accordance with the 8-bit VID code, as defined in Table 7-3. This DAC sets the output voltage.
In adaptive on-time converters, the controller varies the on-time as a function of input and output voltage to maintain a nearly constant frequency during steady-state conditions. With conventional voltage-mode constant on-time converters, each cycle begins when the output voltage crosses to a fixed reference level. However, in the TPS59632-Q1 device, the cycle begins when the current feedback reaches an error voltage level, which corresponds to the amplified difference between the DAC voltage and the feedback output voltage. In the case of 2-phase or 3-phase operation, the device sums the current feedback from all the phases at the output of the internal current-sense amplifiers.
This approach has two advantages:
In addition, the difference between the DAC-to-output voltage and the current feedback goes through an integrator to give an approximately linear load-line slope even at light loads where the inductor current is in discontinuous conduction mode (DCM).
During a steady-state condition, the phases of the TPS59632-Q1 device switch 180° phase-displacement for 2-phase mode and 120° phase-displacement for 3-phase mode. The phase displacement is maintained both by the architecture and current ripple. The architecture does not allow the high-side gate drive outputs of more than one phase to be ON in any condition except transients. The current ripple forces the pulses to be spaced equally. The controller forces current-sharing adjusting the ON time of each phase. Current balancing requires no user intervention, compensation, or extra components.