ISL8105 Datasheet, PDF (1/16 Pages) Intersil Corporation – +5V or +12V Single-Phase Synchronous Buck Converter PWM Controller withIntegrated MOSFET Gate Drivers

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Data Sheet
ISL8105, ISL8105A
April 15, 2010
FN6306.5
+5V or +12V Single-Phase Synchronous
Buck Converter PWM Controller with
Integrated MOSFET Gate Drivers
The ISL8105, ISL8105A is a simple single-phase PWM
controller for a synchronous buck converter. It operates from
+5V or +12V bias supply voltage. With integrated linear
regulator, boot diode, and N-Channel MOSFET gate drivers,
the ISL8105, ISL8105A reduces external component count and
board space requirements. These make the IC suitable for a
wide range of applications.
Utilizing voltage-mode control, the output voltage can be
precisely regulated to as low as 0.6V. The 0.6V internal
reference features a maximum tolerance of ±1.0% over the
commercial temperature range, and ±1.5% over the
industrial temperature range. Two fixed oscillator frequency
versions are available; 300kHz (ISL8105 for high efficiency
applications) and 600kHz (ISL8105A for fast transient
applications).
The ISL8105, ISL8105A features the capability of safe
start-up with pre-biased load. It also provides overcurrent
protection by monitoring the ON-resistance of the
bottom-side MOSFET to inhibit PWM operation
appropriately. During start-up interval, the resistor connected
to BGATE/BSOC pin is employed to program overcurrent
protection condition. This approach simplifies the
implementation and does not deteriorate converter
efficiency.
Pinouts
ISL8105, ISL8105A
(10 LD 3X3 DFN)
TOP VIEW
BOOT 1
TGATE 2
N/C 3
GND 4
BGATE/BSOC 5
GND
10 LX
9 COMP/EN
8 FB
7 N/C
6 VBIAS
ISL8105, ISL8105A
(8 LD SOIC)
TOP VIEW
BOOT 1
TGATE 2
GND ³
BGATE/BSOC 4
8 LX
7 COMP/EN
6 FB
5 VBIAS
Features
• Operates from +5V or +12V Bias Supply Voltage
- 1.0V to 12V Input Voltage Range (up to 20V possible
with restrictions; see “Input Voltage Considerations” on
page 9)
- 0.6V to V_IN Output Voltage Range
• 0.6V Internal Reference Voltage
- ±1.0% Tolerance Over the Commercial Temperature
Range (0°C to +70°C)
- ±1.5% Tolerance Over the Industrial Temperature
Range (-40°C to +85°C).
• Integrated MOSFET Gate Drivers that Operate from
V_BIAS (+5V to +12V)
- Bootstrapped High-side Gate Driver with Integrated
Boot Diode
- Drives N-Channel MOSFETs
• Simple Voltage-Mode PWM Control
- Traditional Dual Edge Modulation
• Fast Transient Response
- High-Bandwidth Error Amplifier
- Full 0% to 100% Duty Cycle
• Fixed Operating Frequency
- 300kHz for ISL8105
- 600kHz for ISL8105A
• Fixed Internal Soft-Start with Pre-biased Load Capability
• Lossless, Programmable Overcurrent Protection
- Uses Bottom-side MOSFET’s r_DS(ON)
• Enable/Disable Function Using COMP/EN Pin
• Output Current Sourcing and Sinking Currents
• Pb-Free (RoHS Compliant)
Applications
• 5V or 12V DC/DC Regulators
• Industrial Power Systems
• Telecom and Datacom Applications
• Test and Measurement Instruments
• Distributed DC/DC Power Architecture
• Point of Load Modules
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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