Datasheet

MAX1714
High-Speed Step-Down Controller
for Notebook Computers
_______________________________________________________________________________________ 9
V
CC
V
IN
4.5V TO 28V
+5V
BIAS SUPPLY
C2
( ) = ARE FOR THE MAX1714B ONLY.
NOTE: IN THE MAX 1714B, AGND AND PGND ARE INTERNALLY CONNECTED TO THE GND PIN.
POWER-GOOD
INDICATOR
L1
V
OUT
SHDN
V+
D2
CMPSH-3
C6
3.3µF
C7
0.1µF
C4
0.22µF
Q1
D1
R2
100k
Q2
C5
4.7µF
R1
20Ω
C1
SKIP
ON/OFF
CONTROL
LOW-NOISE
CONTROL
DL
LX
BST
DH
PGND
(GND)
OUT
FB
PGOOD
V
DD
MAX1714
+5V
+5V
TON
REF
AGND
(GND)
ILIM
Figure 1. Standard Application Circuit
Standard Application Circuit
The standard application circuit (Figure 1) generates a
low-voltage rail for general-purpose use in a notebook
computer (I/O supply, fixed CPU core supply, DRAM
supply). This DC-DC converter steps down a battery or
AC adapter voltage to voltages from 1.0V to 5.5V with
high efficiency and accuracy.
See Table 1 for a list of component selections for com-
mon applications. Table 2 lists component manufacturers.
Detailed Description
The MAX1714 buck controller is targeted for low-voltage
power supplies for notebook computers. Maxim‘s propri-
etary Quick-PWM pulse-width modulator in the MAX1714
is specifically designed for handling fast load steps
while maintaining a relatively constant operating fre-
quency and inductor operating point over a wide range
of input voltages. The Quick-PWM architecture circum-
vents the poor load-transient timing problems of fixed-
frequency current-mode PWMs while also avoiding the
problems caused by widely varying switching frequen-
cies in conventional constant-on-time and constant-off-
time PWM schemes.