DATASHEET
ISL6228 Data Sheet FN9095
Rev 2.00
May 7, 2008 May 7, 2008 High-Performance Dual-Output Buck Controller for Notebook Applications
The ISL6228 IC is a dual channel 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 diodes result in fewer
components and smaller implementation area.
Intersil’s R3 technology combines the best features of fixedfrequency and hysteretic PWMs 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 fixedfrequency PWM controllers. Unlike a conventional hysteretic
converter, each channel of the ISL6228 has an error amplifier
that provides В±1% voltage regulation at the FB pin. Features High performance R3 technology Fast transient response В±1% regulation accuracy: -40В°C to +100В°C Individual power stage input rail for each channel Wide input voltage range: +3.3V to +25V Output voltage range: +0.6V to +5V 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 Fault protection …