Rainbow Electronics MAX15022 - Manual

General Description
The MAX15022 is a dual-output, pulse-width-modulated
(PWM), step-down DC-DC regulator with dual LDO con-
trollers. The device operates from 2.5V to 5.5V and
each output can be adjusted from 0.6V to the input
supply (V
AVIN
). The MAX15022 delivers up to 4A (regu-
lator 1) and 2A (regulator 2) of output current with two
LDO controllers that can be used to drive two external
PNP transistors to provide two additional outputs. This
device offers the ability to adjust the switching frequen-
cy from 500kHz to 4MHz and provides the capability of
optimizing the design in terms of size and performance.
The MAX15022 utilizes a voltage-mode control scheme
with external compensation to provide good noise
immunity and maximum flexibility in selecting inductor
values and capacitor types. The dual switching regula-
tors operate 180° out-of-phase, thereby reducing the
RMS input ripple current and thus the size of the input
bypass capacitor significantly.
The MAX15022 offers the ability to track (coincident or
ratiometric) or sequence during power-up and power-
down operation. When sequencing, it powers up glitch-
free into a prebiased output.
Additional features include an internal undervoltage
lockout with hysteresis and a digital soft-start/soft-stop
for glitch-free power-up and power-down. Protection
features include lossless cycle-by-cycle current limit,
hiccup-mode output short-circuit protection, and ther-
mal shutdown.
The MAX15022 is available in a space-saving, 5mm x
5mm, 28-pin TQFN-EP package and is specified for
operation from -40°C to +125°C temperature range.
Applications
RFID Reader Cards
Power-over-Ethernet (PoE) IP Phones
Automotive Multimedia
Multivoltage Supplies
Networking/Telecom
Features
♦ 2.5V to 5.5V Input-Voltage Range
♦ Dual-Output Synchronous Buck Regulators
♦ Integrated Switches for 4A and 2A Output
Currents
♦ 180° Out-Of-Phase Operation
♦ Output Voltage Adjustable from 0.6V to V
AVIN
♦ Two LDO Controllers
♦ Lossless, Cycle-by-Cycle Current Sensing
♦ External Compensation for Maximum Flexibility
♦ Digital Soft-Start and Soft-Stop for Tracking
Applications
♦ Digital Soft-Start into a Prebiased Load for
Sequencing Applications
♦ Sequencing or Coincident/Ratiometric Tracking
♦ Programmable Switching Frequency from 500kHz
to 4MHz
♦ Thermal Shutdown and Hiccup-Mode Short-
Circuit Protection
♦ 30µA Shutdown Current
♦ 100% Maximum Duty Cycle
♦ Space-Saving (5mm x 5mm) 28-Pin TQFN
Package
MAX15022
Dual, 4A/2A, 4MHz, Step-Down DC-DC
Regulator with Dual LDO Controllers
________________________________________________________________ Maxim Integrated Products 1
MAX15022
THIN QFN
(5mm x 5mm)
TOP VIEW
26
27
25
24
10
9
11
PGND1
PVIN1 PVIN1
LX1
PGND1
12
SEL
EN4 LX2 PGND2 FB4 DVDD2 EN3
1
+
2
EN2
4
*EP
*EP = EXPOSED PAD.
5 6 7
20 21 19 17 16 15
SGND
AVIN
COMP1
FB1
EN1
DVDD1
LX1
PVIN2
3
18
28 8 RT PGND1
FB2
23 13 B3 COMP2
22 14 FB3 B4
Pin Configuration
Ordering Information
19-4107; Rev 0; 5/08
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-PACKAGE
MAX15022ATI+ -40°C to +125°C 28 TQFN-EP*
+ Denotes a lead-free package.
* EP = Exposed pad.