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
fixed-frequency PWM and hysteretic PWM while eliminating
many of their shortcomings. R3™ Technology employs an
innovative modulator that synthesizes an AC ripple voltage
signal VR, analogous to the output inductor ripple current. The
AC signal VR enters a window comparator where the lower
threshold is the error amplifier output VCOMP and the upper
threshold is a programmable voltage reference VW, resulting in
generation of the PWM signal. The voltage reference VW sets
the steady-state PWM frequency. Both edges of the PWM can be
modulated in response to input voltage transients and output
load transients, much faster than conventional fixed-frequency
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 Conduction Mode
(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.

Features
• High performance R3™ Technology
• Fast transient response
• ±1% regulation accuracy: -10°C to +100°C and
-40° to +100°C
• Wide input voltage range: +5V to +25V
• 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 (RoHS compliant)

Applications
• PCI express graphical processing unit
• Auxiliary power rail
• VRM
• Network adapter