ISL6310 Datasheet, PDF (1/27 Pages) Intersil Corporation – Two-Phase Buck PWM Controller with High Current Integrated MOSFET Drivers

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Data Sheet
August 7, 2008
ISL6310
FN9209.4
Two-Phase Buck PWM Controller with
High Current Integrated MOSFET Drivers
The ISL6310 is a two-phase PWM control IC with integrated
MOSFET drivers. It provides a precision voltage regulation
system for multiple applications including, but not limited to,
high current low voltage point-of-load converters, embedded
applications and other general purpose low voltage medium
to high current applications. The integration of power
MOSFET drivers into the controller IC marks a departure
from the separate PWM controller and driver configuration of
previous multi-phase product families. By reducing the
number of external parts, this integration allows for a cost
and space saving power management solution.
Output voltage can be programmed using the on-chip DAC
or an external precision reference. A two bit code programs
the DAC reference to one of 4 possible values (0.6V, 0.9V,
1.2V and 1.5V). A unity gain, differential amplifier is provided
for remote voltage sensing, compensating for any potential
difference between remote and local grounds. The output
voltage can also be offset through the use of single external
resistor. An optional droop function is also implemented and
can be disabled for applications having less stringent output
voltage variation requirements or experiencing less severe
step loads.
A unique feature of the ISL6310 is the combined use of both
DCR and r_DS(ON) current sensing. Load line voltage
positioning and overcurrent protection are accomplished
through continuous inductor DCR current sensing, while
r_DS(ON) current sensing is used for accurate channel-current
balance. Using both methods of current sampling utilizes the
best advantages of each technique.
Protection features of this controller IC include a set of
sophisticated overvoltage and overcurrent protection.
Overvoltage results in the converter turning the lower
MOSFETs ON to clamp the rising output voltage and protect
the load. An OVP output is also provided to drive an optional
crowbar device. The overcurrent protection level is set
through a single external resistor. Other protection features
include protection against an open circuit on the remote
sensing inputs. Combined, these features provide advanced
protection for the output load.
Features
• Integrated Multi-Phase Power Conversion
- 1 or 2-Phase Operation
• Precision Output Voltage Regulation
- Differential Remote Voltage Sensing
- ±0.8% System Accuracy Over-Temperature
(for REF = 0.6V and 0.9V)
- ±0.5% System Accuracy Over-Temperature
(for REF=1.2V and 1.5V)
- Usable for Output Voltages not Exceeding 2.3V
- Adjustable Reference-Voltage Offset
• Precision Channel Current Sharing
- Uses Loss-Less r_DS(ON) Current Sampling
• Optional Load Line (Droop) Programming
- Uses Loss-Less Inductor DCR Current Sampling
• Variable Gate-Drive Bias - 5V to 12V
• Internal or External Reference Voltage Setting
- On-Chip Adjustable Fixed DAC Reference Voltage with
2-bit Logic Input Selects from Four Fixed Reference
Voltages (0.6V, 0.9V, 1.2V, 1.5V)
- Reference can be Changed Dynamically
- Can use an External Voltage Reference
• Overcurrent Protection
• Multi-tiered Overvoltage Protection
- OVP Pin to Drive Optional Crowbar Device
• Selectable Operation Frequency up to 1.5MHz Per Phase
• Digital Soft-Start
• Capable of Start-up in a Pre-Biased Load
• Pb-Free (RoHS Compliant)
Applications
• High Current DDR/Chipset core voltage regulators
• High Current, Low voltage DC/DC converters
• High Current, Low voltage FPGA/ASIC DC/DC converters
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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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