MAX1714 Datasheet, PDF (1/24 Pages) Maxim Integrated Products – High-Speed Step-Down Controller for Notebook Computers

19-1536; Rev 1; 12/99
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High-Speed Step-Down Controller
for Notebook Computers
General Description
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 low-
voltage 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 synchronous-
rectifier 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 mini-
mum 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 overvolt-
age protection. For applications requiring VID compli-
ance or DAC control of output voltage, refer to the
MAX1710/MAX1711 data sheet. For a dual output ver-
sion, refer to the MAX1715^† data sheet.
Applications
Notebook Computers
CPU Core Supply
Chipset/RAM Supply as Low as 1V
1.8V and 2.5V I/O Supply
Quick-PWM is a trademark of Maxim Integrated Products.
† _{Future product—contact factory for availability.}
Pin Configurations appear at end of data sheet.
Features
o Ultra-High Efficiency
o No Current-Sense Resistor (Lossless I_LIMIT)
o Quick-PWM with 100ns Load-Step Response
o 1% V_OUT Accuracy Over Line and Load
o 2.5V/3.3V Fixed or 1V to 5.5V Adjustable Output
Range
o 2V to 28V Battery Input Range
o 200/300/450/600kHz Switching Frequency
o Overvoltage Protection (MAX1714A)
o Undervoltage Protection
o 1.7ms Digital Soft-Start
o Drives Large Synchronous-Rectifier FETs
o 2V ±1% Reference Output
o Power-Good Indicator
PART
MAX1714AEEP
MAX1714BEEE
Ordering Information
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
20 QSOP
16 QSOP
Minimal Operating Circuit
+5V INPUT
V_CC
V_DD
SHDN V+
BATTERY
4.5V TO 28V
ILIM
BST
DH
MAX1714
LX
REF
DL
PGOOD PGND
(GND)
FB
OUT
SKIP
AGND
(GND)
OUTPUT
1.25V TO 2V
( ) ARE FOR THE MAX1714B ONLY.
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