LTC3246

1

3246fa

TYPICAL APPLICATION

FEATURES

DESCRIPTION

Buck-Boost Charge Pump

with Watchdog Timer

converter with integrated watchdog timer. The device

produces a regulated output (3.3V, 5V or adjustable) from

a 2.7V to 38V input. Switched capacitor fractional conver-

sion is used to maintain regulation over a wide range of

input voltage. Internal circuitry automatically selects the

conversionratiotooptimizeefficiencyasinputvoltageand

load conditions vary. No inductors are required.

The LTC3246’s reset time and watchdog timeout may

be set without external components, or adjusted using

external capacitors. A windowed watchdog function is

used for high reliability applications. The reset input can

be used for additional supply monitoring or be configured

as a pushbutton reset.

Low operating current (20µA without load, 1.5µA in shut-

down) and low external parts count make the LTC3246

ideally suited for low power, space constrained automo-

tive/industrial applications. The device is short-circuit and

overtemperature protected and is available in a thermally

enhanced 16-lead MSOP package.

Regulated 5V Output with Pushbutton Reset

Output Voltage vs Input Voltage

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2.7V – 38V Operating Range (42V Abs Max)

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Multimode Buck-Boost Charge Pump (2:1, 1:1, 1:2)

with Automatic Mode Switching

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12V to 5V Efficiency = 81%

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Ultralow EMI Emissions

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Engineered for Diagnostic Coverage in ISO 26262

Systems

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Overtemperature, Overvoltage and Short-Circuit

Protection

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Operating Junction Temperature: 150°C Max

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POR/Watchdog Controller w/External Timing Control

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Thermally Enhanced 16-Lead MSOP Package

APPLICATIONS

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Automotive ECU/CAN Transceiver Supplies

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Industrial/Telecom Housekeeping Supplies

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Low Power 12V to 5V Conversion

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

LTC3246

3246 TA01a

SEL2

SEL1

BIAS

RT

WT

C+

C–

GND

OUTS/ADJ

RST

WDI

RSTI

1µF

10µF

10µF

500k

500k

µC

RESET

2.2µF

0

2

4

6

8

10

12

14

16

4.80

4.85

4.90

4.95

5.00

5.05

5.10

5.15

5.20

3246 TA01b