Rainbow Electronics MAX17101 - Manual

MAX17101
Dual Quick-PWM, Step-Down Controller
with Low-Power LDO, RTC Regulator
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-4243; Rev 0; 8/08
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.
General Description
The MAX17101 is a dual Quick-PWM™ step-down
power-supply (SMPS) controller with synchronous rectifi-
cation, intended for main 5V/3.3V power generation in
battery-powered systems. Low-side MOSFET sensing
provides a simple low-cost, highly efficient current sense
for providing valley current-limit protection. Combined
with the output overvoltage and undervoltage protection
features, this current limit ensures robust output supplies.
The 5V/3.3V SMPS outputs can save power by operating
in pulse-skipping mode or in ultrasonic mode to avoid
audible noise. Ultrasonic mode forces the controller to
maintain switching frequencies greater than 20kHz at
light loads.
An internal 100mA linear regulator can be used to
either generate the 5V bias needed for power-up or
other lower power “always-on” suspend supplies. An
independent bypass input allows automatic bypassing
of the linear regulator when the SMPS is active.
This main controller also includes a secondary feed-
back input that triggers an ultrasonic pulse (DL1 turned
on) if the SECFB voltage drops below its threshold volt-
age. This refreshes an external charge pump driven by
DL1 without overcharging the output voltage.
The device includes independent shutdown controls to
simplify power-up and power-down sequencing. To
prevent current surges at startup, the internal voltage
target is slowly ramped up from zero to the final target
over a 1ms period. To prevent the output from ringing
below ground in shutdown, the internal voltage target
is ramped down from its previous value to zero over a
1ms period. Two independent power-good outputs
simplify the interface with external controllers.
The MAX17101 comes in a lead-free 32-pin TQFN
(5mm x 5mm) package and operates in the -40°C to
+85°C temperature range.
Features
Applications
+ Denotes a lead-free/RoHS-compliant package.
* EP = Exposed pad.
PART TEMP RANGE PIN-PACKAGE
MAX17101ETJ+ -40°C to +85°C 32 Thin QFN-EP*
♦ Dual Quick-PWM
♦ Internal 100mA 5V or Adjustable Linear Regulator
♦ Independent LDO Bypass Input
♦ Internal Boost Diodes
♦ Secondary Feedback Input Maintains Charge Pump
♦ 3.3V 5mA RTC Power (Always On)
♦ OUT1: 5V or 1.5V Fixed or 0.7V Adjustable
Feedback
♦ OUT2: 3.3V or 1.05V Fixed or Dynamic Adjustable
♦ Dynamic 0 to 2V REFIN2 Input on Second Output
♦ 2V ±1% 50µA Reference
♦ 6V to 24V Input Range (28V max)
♦ Ultrasonic Mode
♦ Independent SMPS and LDO Enable Controls
♦ Independent SMPS Power-Good Outputs
♦ Minimal Component Count
Notebook Computers
Main System Supply (5V and 3.3V Supplies)
Graphic Cards
DDR1, DDR2, DDR3 Power Supplies
Game Consoles
Low-Power I/O and Chipset Supplies
Two to Four Li+ Cells Battery-Powered Devices
PDAs and Mobile Communicators
Telecommunication
MAX17101
THIN QFN
TOP VIEW
A "+" SIGN FIRST-PIN INDICATOR DENOTES A LEAD-FREE PACKAGE.
29
30
28
27
12
11
13
TON
ONLDO
RT
C IN
LDO
14
REF
DL2 AGND SECFB BST2 V
DD
DL1
1 2
PGOOD2
4 5 6 7
23 24 22 20 19 18
SKIP
OUT2
ON1
PGOOD1
ILIM1
FB1
V
CC
PGND
3
21
31 10 ILIM2 OUT1
32 9 REFIN2
+
BYP
ON2
26 15 DH1 DH2
25 16 LX1
LDOSEL
BST1
8
17
LX2
Pin Configuration
Quick-PWM is a trademark of Maxim Integrated Products, Inc.
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