MAX1537 Maxim Integrated Products, MAX1537 Datasheet
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MAX1537
Manufacturer Part Number
MAX1537
Description
Main Power-Supply Controllers
Manufacturer
Maxim Integrated Products
Datasheet
1.MAX1537.pdf
(38 pages)
The MAX1533/MAX1537 are dual step-down, switch-
mode power-supply (SMPS) controllers with synchro-
nous rectification, intended for main 5V/3.3V power
generation in battery-powered systems. Fixed-frequen-
cy operation with optimal interleaving minimizes input
ripple current from the lowest input voltages up to the
26V maximum input. Optimal 40/60 interleaving allows
the input voltage to go down to 8.3V before duty-cycle
overlap occurs, compared to 180° out-of-phase regula-
tors where the duty-cycle overlap occurs when the
input drops below 10V. Output current sensing pro-
vides accurate current limit using a sense resistor.
Alternatively, power dissipation can be reduced using
lossless inductor current sensing.
Internal 5V and 3.3V linear regulators power the
MAX1533/MAX1537 and their gate drivers, as well as
external keep-alive loads, up to a total of 100mA. When
the main PWM regulators are in regulation, automatic
bootstrap switches bypass the internal linear regulators,
providing currents up to 200mA from each linear output.
An additional 5V to 23V adjustable internal 150mA linear
regulator is typically used with a secondary winding to
provide a 12V supply.
The MAX1533/MAX1537 include on-board power-up
sequencing, a power-good (PGOOD) output, digital
soft-start, and internal soft-shutdown output discharge
that prevents negative voltages on shutdown. The
MAX1533 is available in a 32-pin 5mm x 5mm thin QFN
package, and the MAX1537 is available in a 36-pin
6mm x 6mm thin QFN package. The exposed backside
pad improves thermal characteristics for demanding
linear keep-alive applications.
19-3501; Rev 0; 11/04
+Denotes lead-free package.
Dual Mode is a trademark of Maxim Integrated Products, Inc.
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.
MAX1533ETJ
MAX1533ETJ+
MAX1537ETX
MAX1537ETX+
High-Efficiency, 5x Output, Main Power-Supply
PART
2 to 4 Li+ Cells Battery-Powered Devices
Notebook and Subnotebook Computers
PDAs and Mobile Communicators
-40°C to +85°C 32 Thin QFN 5mm x 5mm
-40°C to +85°C 32 Thin QFN 5mm x 5mm
-40°C to +85°C 36 Thin QFN 6mm x 6mm
-40°C to +85°C 36 Thin QFN 6mm x 6mm
TEMP RANGE
________________________________________________________________ Maxim Integrated Products
Ordering Information
General Description
Controllers for Notebook Computers
PIN-PACKAGE
Applications
♦ Fixed-Frequency, Current-Mode Control
♦ 40/60 Optimal Interleaving
♦ Accurate Differential Current-Sense Inputs
♦ Internal 5V and 3.3V Linear Regulators with
♦ Auxiliary 12V or Adjustable 150mA Linear
♦ Dual-Mode™ Feedback—3.3V/5V Fixed or
♦ 200kHz/300kHz/500kHz Switching Frequency
♦ Versatile Power-Up Sequencing
♦ Adjustable Overvoltage and Undervoltage
♦ 6V to 26V Input Range
♦ 2V ±0.75% Reference Output
♦ Power-Good Output
♦ Soft-Shutdown
♦ 5µA (typ) Shutdown Current
100mA Load Capability
Regulator (MAX1537 Only)
Adjustable Output (Dual Mode) Voltages
Protection
TOP VIEW
ILIM3
ILIM5
FSEL
Pin Configurations continued at end of data sheet.
GND
ON5
ON3
REF
V
CC
1
2
3
4
5
6
7
8
32
9
31
10
11
30
5mm x 5mm
THIN QFN
MAX1533
12
29
Pin Configurations
13
28
14
27
www.DataSheet4U.com
15
26
16
25
Features
24
23
22
21
20
19
18
17
FB5
LDO5
DL5
PGND
DL3
LDO3
FB3
CSL3
1