19-1536; Rev 2; 8/05
KIT
ATION
EVALU
LE
B
AVAILA
High-Speed Step-Down Controller
for Notebook Computers
The MAX1714 pulse-width modulation (PWM) controller
provides the high efficiency, excellent transient
response, and high DC output accuracy needed for
stepping down high-voltage batteries to generate lowvoltage CPU core or chip-set/RAM supplies in notebook
computers.
Maxim’s proprietary Quick-PWM™ quick-response,
constant-on-time PWM control scheme handles wide
input/output voltage ratios with ease and provides
100ns “instant-on” response to load transients while
maintaining a relatively constant switching frequency.
The MAX1714 achieves high efficiency at a reduced
cost by eliminating the current-sense resistor found in
traditional current-mode PWMs. Efficiency is further
enhanced by an ability to drive very large synchronousrectifier MOSFETs.
Single-stage buck conversion allows these devices to
directly step down high-voltage batteries for the highest
possible efficiency. Alternatively, two-stage conversion
(stepping down the +5V system supply instead of the
battery) at a higher switching frequency allows the minimum possible physical size.
The MAX1714 is intended for CPU core, chipset,
DRAM, or other low-voltage supplies as low as 1V. The
MAX1714A is available in a 20-pin QSOP package and
includes overvoltage protection. The MAX1714B is
available in a 16-pin QSOP package with no overvoltage protection. For applications requiring VID compliance or DAC control of output voltage, refer to the
MAX1710/MAX1711 data sheet. For a dual output version, refer to the MAX1715† data sheet.
Features
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Ultra-High Efficiency
No Current-Sense Resistor (Lossless ILIMIT)
Quick-PWM with 100ns Load-Step Response
1% VOUT Accuracy Over Line and Load
2.5V/3.3V Fixed or 1V to 5.5V Adjustable Output
Range
2V to 28V Battery Input Range
200/300/450/600kHz Switching Frequency
Overvoltage Protection (MAX1714A)
Undervoltage Protection
1.7ms Digital Soft-Start
Drives Large Synchronous-Rectifier FETs
2V ±1% Reference Output
Power-Good Indicator
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX1714AEEP
-40°C to +85°C
20 QSOP
MAX1714AEEP+
-40°C to +85°C
20 QSOP
MAX1714BEEE
-40°C to +85°C
16 QSOP
MAX1714BEEE+
-40°C to +85°C
+Denotes lead-free package.
16 QSOP
Minimal Operating Circuit
BATTERY
4.5V TO 28V
+5V INPUT
Applications
VCC
SHDN
VDD
V+
ILIM
Notebook Computers
BST
CPU Core Supply
Chipset/RAM Supply as Low as 1V
OUTPUT
1.25V TO 2V
DH
1.8V and 2.5V I/O Supply
MAX1714
LX
REF
DL
PGOOD PGND
(GND)
FB
OUT
SKIP
Quick-PWM is a trademark of Maxim Integrated Products.
†
Future product—contact factory for availability.
Pin Configurations appear at end of data sheet.
AGND
(GND)
( ) ARE FOR THE MAX1714B ONLY.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX1714
General Description
