ISL6268 Datasheet, PDF (1/14 Pages) Intersil Corporation – High-Performance Notebook PWM Controller

®
Data Sheet
August 22, 2006
ISL6268
FN6348.0
High-Performance Notebook PWM
Controller
The ISL6268 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 ISL6268 has an error
amplifier that provides ±1% voltage regulation at the FB pin.
The ISL6268 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 ISL6268
normally operates in continuous-conduction-mode (CCM),
automatically entering diode-emulation-mode (DEM) at low
load for optimum efficiency. In CCM the converter operates
as a synchronous rectifier. In DEM the low-side MOSFET
stays off, blocking negative current flow from the output
inductor.
Pinout
ISL6268 (16 LD SSOP)
TOP VIEW
PHASE 1
PGOOD 2
VIN 3
VCC 4
EN 5
COMP 6
FB 7
GND 8
16 UG
15 BOOT
14 PVCC
13 LG
12 PGND
11 ISEN
10 VO
9 FSET
Features
• High performance R³ technology
• Fast transient response
• ±1% regulation accuracy: -10°C to +100°C
• Wide input voltage range: +7.0V to +25.0V
• Output voltage range: +0.6V to +3.3V
• Wide output load range: 0A to 25A
• 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
- 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 plus anneal available (RoHS compliant)
Applications
• PCI express graphical processing unit
• Auxiliary power rail
• VRM
• Network adapter
Ordering Information
PART
PART
PKG.
NUMBER MARKING TEMP (°C) PACKAGE DWG. #
ISL6268CAZ 6268CAZ -10 to +100 16 Ld QSOP M16.15A
(Note)
(Pb-free)
ISL6268CAZ-T 6268CAZ 16 Ld QSOP Tape and
(Note)
Reel (Pb-free)
M16.15A
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100%
matte tin plate termination finish, which are RoHS compliant and
compatible with both SnPb and Pb-free soldering operations. Intersil
Pb-free products are MSL classified at Pb-free peak reflow
temperatures that meet or exceed the Pb-free requirements of
IPC/JEDEC J STD-020.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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