1

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ISL8105, ISL8105A

+5V or +12V Single-Phase Synchronous

Buck Converter PWM Controller with

Integrated MOSFET Gate Drivers

The ISL8105 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 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 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

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)

• 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).

(+5V to +12V)

- Bootstrapped High-side Gate Driver with Integrated

Boot Diode

- Drives N-Channel MOSFETs

• Simple Voltage-Mode PWM Control

• 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

• Enable/Disable Function Using COMP/EN Pin

• Output Current Sourcing and Sinking Currents

• Pb-Free Plus Anneal Available (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

ISL8105

(10 LD 3X3 DFN)

TOP VIEW

ISL8105

(8 LD SOIC)

TOP VIEW

BOOT

TGATE

N/C

GND

BGATE/BSOC

LX

COMP/EN

FB

N/C

VBIAS

2

3

4

1

5

9

8

7

10

6

GND

LX

COMP/EN

FB

VBIAS

BOOT

TGATE

GND

BGATE/BSOC

2

3

4

1

5

8

7

6

Data Sheet

December 6, 2006

FN6306.3

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

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