ISL6269B_14 Datasheet, PDF (1/16 Pages) Intersil Corporation – High-Performance Notebook PWM Controller With Audio-Frequency Clamp

DATASHEET
High-Performance Notebook PWM Controller With
Audio-Frequency Clamp
ISL6269B
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 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 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 r_DS(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
November 17, 2014
1
FN6280.3
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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