LT8650SP

1

Rev. B

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LOAD CURRENT (A)

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CH1 5V

CH2 3.3V

VIN1 = VIN2 = 12V

fSW = 2MHz

8650sp TA01b

The LT®8650SP is a dual step-down regulator that delivers

up to 6A of continuous current from both channels with a

heat sink and supports loads up to 8A from each channel.

The LT8650SP features second generation Silent Switcher

architecture to minimize EMI emissions while delivering

high efficiency at high switching frequencies. This includes

integrationofbypasscapacitorstooptimizehighfrequency

current loops and make it easy to achieve advertised EMI

performancebyeliminatinglayoutsensitivity.Thetopofthe

package features exposed die for heat sink attach which is

required to meet maximum output current ratings.

Thefast,clean,low-overshootswitchingedgesenablehigh

efficiency operation even at high switching frequencies,

leading to a small overall solution size. Peak current mode

control with a 40ns minimum on-time allows high step

down ratios at high switching frequencies.

Burst Mode operation features a 6.2μA quiescent current

resulting in high efficiency at low output currents, forced

continuous mode allows fixed switching frequency opera-

tionovertheentireoutputloadrange,andspreadspectrum

operation can further reduce EMI emissions. External VC

pins allow optimal loop compensation for fast transient

response. The VC pins can also be used for current sharing

andtheCLKOUTpinenablessynchronizingtwoLT8650SP

chips to generate a 4-phase, 24A supply.

TYPICAL APPLICATION

FEATURES

DESCRIPTION

Dual Channel 6A, 42V, Synchronous Step-Down

Silent Switcher 2 with 6.2µA Quiescent Current

5V/6A, 3.3V/6A 2MHz Step-Down Converter

Efficiency

APPLICATIONS

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Silent Switcher®2 Architecture:

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Ultralow EMI on Any PCB

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Eliminates PCB Layout Sensitivity

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Internal Bypass Capacitors Reduce Radiated EMI

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Optional Spread Spectrum Modulation

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Exposed Die Package for Heat Sink Mount

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6A DC from Each Channel Simultaneously

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Up to 8A on Either Channel

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Ultralow Quiescent Current Burst Mode® Operation:

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6.2μA IQ Regulating 12VIN to 5VOUT1 and 3.3VOUT2

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Output Ripple <10mVP-P

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Optional External VC Pin: Fast Transient Response

and Current Sharing (Extra 50µA IQ/Channel)

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Forced Continuous Mode

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High Efficiency at High Frequency

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94.6% Efficiency at 2A, 5VOUT from 12VIN at 2MHz

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93.3% Efficiency at 4A, 5VOUT from 12VIN at 2MHz

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Fast Minimum Switch-On Time: 40ns

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Wide Input Voltage Range: 3.0V to 42V

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Adjustable and Synchronizable: 300kHz to 3MHz

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4mm × 6mm 32-Lead LQFN Exposed Back Package

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AEC-Q100 Qualified for Automotive Applications

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General Purpose Step-Down

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Automotive and Industrial Supplies

All registered trademarks and trademarks are the property of their respective owners. Protected

by U.S. patents, including 8823345.

8650sp TA01a

VIN2

VIN2

3.7V TO 42V

VOUT2

3.3V

6A

EN/UV2

LT8650SP

SW2

FB2

VC2

VCC

SS2

10µF

1.0µH

VIN1

EN/UV1

SW1

FB1

VC1

VCC

SS1

RT

BIAS

10nF

4.7pF

47µF

×2

1M

316k

VIN1

5.4V TO 42V

VOUT1

5V

6A

10µF

10nF

47µF

×2

4.7pF

1M

191k

1.0µH

1µF

15k

fSW = 2MHz

GND SYNC

VCC