The ISL6269B IC is a Single-Phase Synchronous-Buck PWM controller featuring Intersil's Robust Ripple Regulator (R³) technology that delivers truly superior dynamic response to input voltage and output load transients. Integrated MOSFET drivers and bootstrap diode result in fewer components and smaller implementation area.

Intersil's R³ technology combines the best features of fixedfrequency PWM and hysteretic PWM while eliminating many of their shortcomings. R³ technology employs an innovative modulator that synthesizes an AC ripple voltage signal V_R, analogous to the output inductor ripple current. The AC signal V_R enters a window comparator where the lower threshold is the error amplifier output V_COMP, and the upper threshold is a programmable voltage reference V_W, resulting in generation of the PWM signal. The voltage reference V_W sets the steadystate PWM frequency. Both edges of the PWM can be modulated in response to input voltage transients and output load transients, much faster than conventional fixedfrequency PWM controllers. Unlike a conventional hysteretic converter, the ISL6269B has an error amplifier that provides ±1% voltage regulation at the FB pin.

The ISL6269B has a 1.5ms digital soft-start and can be started into a pre-biased output voltage. A resistor divider is used to program the output voltage setpoint. The ISL6269B can be configured to operate in continuous-conductionmode (CCM) or diode-emulation-mode (DEM), which improves light-load efficiency. In CCM the controller always operates as a synchronous rectifier however, when DEM is enabled the low-side MOSFET is permitted to stay off, blocking negative current flow into the low-side MOSFET from the output inductor.

• High performance R³ technology
• Fast transient response
• ±1% regulation accuracy: -10°C to +100°C and -40° to +100°C
• Wide input voltage range: +5.0V to +25.0V
• Output voltage range: +0.6V to +3.3V
• Wide output load range: 0A to 25A
• Selectable diode emulation mode for increased light load efficiency
• Programmable PWM frequency: 200kHz to 600kHz
• Pre-biased output start-up capability
• Integrated MOSFET drivers and bootstrap diode
• Internal digital soft-start
• Power good monitor
• PWM minimum frequency above audible spectrum
• Fault protection
  • Undervoltage protection
  • Soft crowbar overvoltage protection
  • Low-side MOSFET rDS(ON) overcurrent protection
  • Over-temperature protection
  • Fault identification by PGOOD pull down resistance
• Pb-free plus anneal available (RoHS compliant)

• PCI express graphical processing unit
• Auxiliary power rail
• V_RM
• Network adapter