4.5V to 28V Input, Synchronous PWM Buck Controllers

for DDR Termination and Point-of-Load Applications

______________________________________________________________________________________

13

Functional Diagrams (continued)

Σ

Σ

Q

S

R

Q

TRIG

ONE-SHOT

TRIG

Q

ONE-SHOT

TON

ON-TIME

COMPUTE

OUT

LATCH

Q

RS

FB

POK

ERROR

COMP

OVP

VL

5V

REG

2V

REF

/10

5

µA

MAX8554

FSEL

POK

GND

REF

VL

FB

PGND

DL

V+

LX

DH

BST

ILIM

EN

HSD

0.672V

0.528V

0.720V

0.600V