MAX1540AETJ Datasheet, PDF (1/49 Pages) Maxim Integrated Products – Dual Step-Down Controllers with Saturation Protection, Dynamic Output, and Linear Regulator

19-2861; Rev 3; 2/07
EVAALVUAAILTAIOBNLEKIT
Dual Step-Down Controllers with Saturation
Protection, Dynamic Output, and Linear Regulator
General Description
The MAX1540A/MAX1541 dual pulse-width modulation
(PWM) controllers provide the high efficiency, excellent
transient response, and high DC-output accuracy nec-
essary for stepping down high-voltage batteries to gen-
erate low-voltage chipset and RAM power supplies in
notebook computers.
The Maxim proprietary Quick-PWM™ controllers are
free running, constant on-time with input feed forward.
This configuration provides ultra-fast transient
response, wide input-output (I/O) differential range, low
supply current, and tight load-regulation characteris-
tics. The controllers can accurately sense the inductor
current across an external current-sense resistor in
series with the output to ensure reliable overload and
inductor saturation protection. Alternatively, the con-
trollers can use the synchronous rectifier itself or loss-
less inductor current-sensing methods to provide
overload protection with lower power dissipation.
For a single step-down PWM controller with inductor-
saturation protection, external-reference input voltage,
and dynamically selectable output voltages, refer to the
MAX1992/MAX1993 data sheet.
Applications
Notebook Computers
Core/I/O Supplies as Low as 0.7V
0.7V to 5.5V Supply Rails
CPU/Chipset/GPU with Dynamic Voltage Core
Supplies (MAX1541)
DDR Memory Termination (MAX1541)
Active Termination Buses (MAX1541)
Ordering Information
PART
TEMP RANGE
MAX1540AETJ -40°C to +85°C
MAX1540AETJ+ -40°C to +85°C
MAX1541ETL -40°C to +85°C
MAX1541ETL+ -40°C to +85°C
+Denotes a lead-free package.
PIN-
PACKAGE
32 Thin QFN
5mm x 5mm
32 Thin QFN
5mm x 5mm
40 Thin QFN
6mm x 6mm
40 Thin QFN
6mm x 6mm
PKG
CODE
T3255-4
T3255-4
T4066-5
T4066-5
Quick-PWM is a trademark of Maxim Integrated Products, Inc.
Features
♦ Inductor-Saturation Protection
♦ Accurate Differential Current-Sense Inputs
♦ Dual Ultra-High-Efficiency Quick-PWMs with
100ns Load-Step Response
♦ MAX1540A
1.8V/1.2V Fixed or 0.7V to 5.5V Adjustable
Output (OUT1)
2.5V/1.5V Fixed or 0.7V to 5.5V Adjustable
Output (OUT2)
Fixed 5V, 100mA Linear Regulator
♦ MAX1541
External Reference Input (REFIN1)
Dynamically Selectable Output Voltage—0.7V
to 5.5V (OUT1)
2.5V/1.8V Fixed or 0.7V to 5.5V Adjustable
Output (OUT2)
Optional Power-Good and Fault Blanking
During Transitions
Fixed 5V or Adjustable 100mA Linear Regulator
♦ 1% V_OUT Accuracy over Line and Load
♦ 2V to 28V Battery Input Range
♦ 170kHz to 620kHz Selectable Switching
Frequency
♦ Overvoltage/Undervoltage-Protection Option
♦ 1.7ms Digital Soft-Start
♦ Drives Large Synchronous-Rectifier FETs
♦ 2V ±0.7% Reference Output
♦ Separate Power-Good Window Comparators
Pin Configurations
TOP VIEW
DH1 25
PGOOD1 26
OUT1 27
FB1 28
CSN1 29
CSP1 30
ON2 31
ON1 32
MAX1540A
16 BST2
15 LX2
14 DH2
13 PGOOD2
12 OUT2
11 FB2
10 CSN2
9 CSP2
THIN QFN
A "+" SIGN WILL REPLACE THE FIRST PIN INDICATOR ON LEAD-FREE PACKAGES.
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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