ISL8121 Datasheet, PDF (1/26 Pages) Intersil Corporation – 3V to 20V, Two-Phase Buck PWM Controller with Integrated 4A MOSFET Drivers

3V to 20V, Two-Phase Buck PWM Controller with
Integrated 4A MOSFET Drivers
ISL8121
The ISL8121 is a two-phase buck PWM controller
featuring an input voltage range of 3V to 20V and
integrated MOSFET drivers. Precision voltage regulation
is provided for point-of-load and other high-current
applications that require efficient and compact
implementation. Multiphase buck converter architecture
uses interleaved timing to multiply channel ripple
frequency allowing smaller filter inductors and reducing
input and output ripple currents due to the ripple
cancellation effect. Lower ripple results in fewer input
and output capacitors. Smaller and low cost transistors
can be used resulting from the higher efficiency and
reduced power dissipation.
The ISL8121 offers an internal 0.6V reference with a
system regulation accuracy of ±0.8% (Industrial
Temperature range), an optional external reference
input, and user-adjustable switching frequency. Unity
gain differential amplifier targeted at remote voltage
sensing capability enhances the regulation. A power good
signal (PGD) is issued when the output voltage is within
the regulated window. An internal shunt regulator with
optional external connection capability extends the
operational input voltage range. For applications
requiring voltage tracking or sequencing, the ISL8121
offers a host of possibilities, including coincidental,
ratiometric, or offset tracking, as well as sequential start-
ups, user adjustable for a wide range of applications.
Additional features include overvoltage and overcurrent
protection. Overcurrent protection can be tailored to
various applications with no need for additional parts.
The ISL8121 uses cost and space-saving r_DS(ON) sensing
for channel current balance, dynamic voltage positioning,
and overcurrent protection. Channel current balancing is
automatic and accurate with the integrated current-
balance control system.
Features
• Integrated Two-Phase Power Conversion
• Precision Output Voltage Regulation
- ±0.8% System Accuracy Over-Temperature
(Industrial)
- Differential Remote Voltage Sensing for Increased
Voltage Sensing Accuracy
• Shunt Regulator for Wide Input Power Conversion
- 5V and Higher Bias
- Up to 20V Power Down-Conversion
• Precision Channel Current Sharing
- Loss-Less r_DS(ON) Current Sampling
• Integrated High Capable 4A Drivers
• 0.6V Internal Reference
• Full Spectrum Voltage Tracking
- Coincidental, Ratiometric, or Offset
• Sequential Start-up Control
• Selectable Switching Frequency up to 2MHz Per
Phase
• Fast Transient Recovery Time
• Overcurrent Protection
• Overvoltage Protection
• Capable of Start-up in a Pre-Biased Load
• QFN Packages:
- QFN - Compliant to JEDEC PUB95 MO-220
- QFN - Quad Flat No Leads - Package Outline
- Near Chip Scale Package footprint, which improves
PCB efficiency and has a thinner profile
• Pb-Free Available (RoHS Compliant)
Applications
• General Purpose High Current DC/DC Converters
• High Current, Low Voltage FPGA/ASIC DC/DC
Converters
• Telecom System
October 27, 2009
FN6352.2
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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