High-Efficiency Step-Up Converters with

Reverse Battery Protection

8

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RESET

1.1V

RST

OUT

SHDN

N

STARTUP

CIRCUITRY

CONTROL

LOGIC

DRIVER

MAX1833

MAX1835

1.228V

ERROR

COMPARATOR

P

N

LX

BATT

GND

N

ZERO-

CROSSING

DETECTOR

CURRENT

LIMIT

REVERSE BATTERY

PROTECTION MOSFET

Figure 3. MAX1833/MAX1835 Simplified Functional Diagram

FB

OUT

SHDN

STARTUP

CIRCUITRY

CONTROL

LOGIC

DRIVER

MAX1832

MAX1834

1.228V

ERROR

COMPARATOR

P

N

LX

BATT

GND

N

ZERO-

CROSSING

DETECTOR

CURRENT

LIMIT

REVERSE BATTERY

PROTECTION MOSFET

Figure 2. MAX1832/MAX1834 Simplified Functional Diagram