Low-Cost Voltage-Mode PWM

Step-Down Controllers

8

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MAX1966

2.7V TO

5.5V INPUT

VIN

COMP/EN

GND

BST

DH

LX

DL

FB

C2

N1

N2

C6

R2

R1

C5

D1

C3

C4

L1

C7

C1

R3

Figure 3. MAX1966 Typical Application

MAX1967

5V TO

28V INPUT

VIN

COMP/EN

GND

BST

VCC

VL

DH

LX

DL

FB

R2

R1

C3

C4

L1

C2

C5

D1

C7

N1

N2

C6

R3

C1

R4

10

Ω

10

Ω

Figure 4. MAX1967 Typical Application

TEMPERATURE

SHUTDOWN

CONTROL

LOGIC

RAMP

GENERATOR

SOFT-START

100kHZ

CLOCK

GENERATOR

DH

DL

GND

CURRENT-LIMIT

COMPARATOR

ERROR

COMPARATOR

ERROR

AMPLIFIER

-305mV

LX

BST

VIN

COMP/EN

FB

800mV

REF

MAX1966

Figure 1. MAX1966 Functional Diagram

TEMPERATURE

SHUTDOWN

CONTROL

LOGIC

5V LINEAR

REGULATOR

RAMP

GENERATOR

SOFT-START

100kHZ

CLOCK

GENERATOR

DH

DL

GND

CURRENT-LIMIT

COMPARATOR

ERROR

COMPARATOR

ERROR

AMPLIFIER

-305mV

LX

BST

VIN

VL

COMP/EN

FB

800mV

REF

INTERNAL

CHIP

SUPPLY

MAX1967

Figure 2. MAX1967 Functional Diagram

SEE TABLE 1 FOR COMPONENT VALUES.

SEE TABLE 1 FOR COMPONENT VALUES.