19-4305; Rev 0; 10/08
KIT
ATION
EVALU
E
BL
AVAILA
Dual Quick-PWM Step-Down Controller with Low-
Power LDO and RTC Regulator for MAIN Supplies
General Description
The MAX17031 is a dual Quick-PWM™ step-down
power-supply (SMPS) controller with synchronous recti-
fication, 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 valley current-limit protection. Combined with
the output overvoltage and undervoltage protection fea-
tures, this current limit ensures robust output supplies.
The 5V/3.3V SMPS outputs can save power by operat-
ing in pulse-skipping mode or in ultrasonic mode to
avoid audible noise. Ultrasonic mode forces the con-
troller to maintain switching frequencies greater than
20kHz at light loads. The SKIP input also has an accu-
rate logic threshold, allowing it to be used as a sec-
ondary feedback input to refresh an external charge
pump or secondary winding without overcharging the
output voltages.
An internal 100mA linear regulator generates the 5V
bias needed for power-up or other low-power “always-
on” suspend supplies. An internal bypass circuitry
allows automatic bypassing of the linear regulator when
the 5V SMPS is active.
The device includes independent shutdown controls
with well-defined logic thresholds 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 peri-
od. 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. A
combined power-good (PGOOD) output simplifies the
interface with external controllers. The MAX17031 is
available in a 24-pin thin QFN (4mm x 4mm) package.
o
Dual Quick-PWM
o
Preset 5V and 3.3V Outputs
o
Internal 100mA, 5V Linear Regulator
o
Internal OUT1 LDO5 Bypass Switch
o
Secondary Feedback (SKIP Input) Maintains
Charge Pump
o
3.3V, 5mA Real-Time Clock (RTC) Power (Always
On)
o
2V ±1% 50µA Reference
o
6V to 24V Input Range
o
Pulse-Skipping/Forced-PWM/Ultrasonic Mode
Control
o
Independent SMPS and LDO5 Enable Controls
o
Combined SMPS PGOOD Outputs
o
Minimal Component Count
Features
MAX17031
Ordering Information
PART
MAX17031ETG+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
24 TQFN-EP*
+Denotes
a lead-free/RoHS-compliant package.
*EP
= Exposed pad.
Pin Configuration
BST2
DL2
V
DD
BST1
13
12
11
10
LX1
DH1
ON1
PGOOD
ILIM1
OUT1
9
*EP
8
7
1
REF
2
ONLDO
3
V
CC
4
RTC
5
IN
6
LDO5
GND
DL1
14
TOP VIEW
18
LX2 19
DH2 20
ON2 21
SKIP 22
OUT2 23
ILIM2 24
17
16
15
Applications
Notebook Computers
Ultra-Mobile PC
Main System Supply (5V and 3.3V Supplies)
2 to 4 Li+ Cells Battery-Powered Devices
Telecommunication
MAX17031
+
THIN QFN
4mm
×
4mm
Quick-PWM is a trademark of Maxim Integrated Products, Inc.
*EXPOSED PAD.
________________________________________________________________
Maxim Integrated Products
1
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.
Dual Quick-PWM Step-Down Controller with Low-
Power LDO and RTC Regulator for MAIN Supplies
MAX17031
ABSOLUTE MAXIMUM RATINGS
IN to GND ...............................................................-0.3V to +28V
V
DD
, V
CC
to GND .....................................................-0.3V to +6V
RTC, LDO5, ONLDO to GND ...................................-0.3V to +6V
OUT2 to GND ...........................................................-0.3V to +6V
ON1, ON2, PGOOD to GND.....................................-0.3V to +6V
OUT1 to GND..........................................-0.3V to (V
LDO5
+ 0.3V)
SKIP to GND...............................................-0.3V to (V
CC
+ 0.3V)
REF, ILIM1, ILIM2 to GND ..........................-0.3V to (V
CC
+ 0.3V)
DL_ to GND ................................................-0.3V to (V
DD
+ 0.3V)
BST_ to GND ..........................................................-0.3V to +36V
BST_ to V
DD
............................................................-0.3V to +30V
DH1 to LX1 ..............................................-0.3V to (V
BST1
+ 0.3V)
BST1 to LX1..............................................................-0.3V to +6V
Note:
Measurements are valid using a 20MHz bandwidth limit.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DH2 to LX2 ..............................................-0.3V to (V
BST2
+ 0.3V)
BST2 to LX2..............................................................-0.3V to +6V
LDO5, RTC, REF Short Circuit to GND.......................Momentary
RTC Current Continuous.....................................................+5mA
LDO5 Current (Internal Regulator) Continuous ..............+100mA
LDO5 Current (Switched Over) Continuous ...................+200mA
Continuous Power Dissipation (T
A
= +70°C)
24-Pin, 4mm x 4mm Thin QFN (T2444-3)
(derate 27.8mW/°C above +70°C) .................................2.22W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 2, no load on LDO5, RTC, OUT1, OUT2, and REF, V
IN
= 12V, V
DD
= V
CC
= V
SKIP
= 5V, ONLDO = RTC, ON1 = ON2
= V
CC
,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
INPUT SUPPLIES
IN Input Voltage Range
IN Standby Supply Current
IN Shutdown Supply Current
IN Supply Current
V
CC
Bias Supply Current
PWM CONTROLLERS
OUT1 Output-Voltage Accuracy
OUT2 Output-Voltage Accuracy
Load Regulation Error
Line Regulation Error
DH1 On-Time
DH2 On-Time
Minimum Off-Time
Soft-Start Slew Rate
Ultrasonic Operating Frequency
t
ON1
t
ON2
t
OFF(MIN)
t
SS
V
OUT1
V
OUT2
V
SKIP
= 1.8V
V
SKIP
= 1.8V
Either SMPS, V
SKIP
= 1.8V, I
LOAD
= 0 to 5A
Either SMPS, V
SKIP
= GND, I
LOAD
= 0 to 5A
Either SMPS, V
SKIP
= V
CC
, I
LOAD
= 0 to 5A
Either SMPS, IN = 6V to 28V
V
OUT1
= 5.0V (Note 1)
V
OUT2
= 3.3V (Note 1)
(Note 1)
Rising/falling edge on ON1 or ON2
20
895
833
4.95
3.267
5.00
3.30
-0.1
-1.7
-1.5
0.005
1052
925
300
1
34
1209
1017
400
%/V
ns
ns
ns
ms
kHz
%
5.05
3.333
V
V
I
IN
I
VCC
LDO5 in regulation
V
IN
= 6V to 24V, ON1 = ON2 = GND,
ONLDO = RTC
V
IN
= 4.5V to 24V,
ON1 = ON2 = ONLDO = GND
ON1 = ON2 = V
CC
, V
SKIP
= V
CC
;
V
OUT1
= 5.3V, V
OUT2
= 3.5V
ON1 = ON2 = V
CC
, V
SKIP
= V
CC
;
V
OUT1
= 5.3V, V
OUT2
= 3.5V
6
85
40
0.1
0.7
24
175
70
0.2
1.5
V
µA
µA
mA
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
f
SW(USONIC)
V
SKIP
= GND
2
_______________________________________________________________________________________
Dual Quick-PWM Step-Down Controller with Low-
Power LDO and RTC Regulator for MAIN Supplies
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 2, no load on LDO5, RTC, OUT1, OUT2, and REF, V
IN
= 12V, V
DD
= V
CC
= V
SKIP
= 5V, ONLDO = RTC, ON1 = ON2
= V
CC
,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
LINEAR REGULATOR (LDO5)
LDO5 Output-Voltage Accuracy
LDO5 Short-Circuit Current
LDO5 Regulation Reduction/
Bootstrap Switchover Threshold
LDO5 Bootstrap Switch Resistance
V
CC
Undervoltage Lockout
Threshold
Thermal-Shutdown Threshold
T
SHDN
V
LDO5
V
IN
= 6V to 24V, ON1 = GND,
0 < I
LDO5
< 100mA
LDO5 = GND
Falling edge of OUT1
Rising edge of OUT1
LDO5 to OUT1, V
OUT1
= 5V (Note 3)
Falling edge of V
CC
, PWM disabled
below this threshold
Rising edge of V
CC
Hysteresis = 10°C
ON1 = ON2 = GND, V
IN
= 6V to 24V,
0 < I
RTC
< 5mA
ON1 = ON2 = ONLDO = GND,
V
IN
= 6V to 24V, 0 < I
RTC
< 5mA
RTC = GND
V
REF
V
REF
V
REF(UVLO)
V
CC
= 4.5V to 5.5V, I
REF
= 0
I
REF
= -20µA to +50µA
Rising edge, 350mV (typ) hysteresis
3.3V ALWAYS-ON LINEAR REGULATOR (RTC)
3.23
3.19
5
1.980
-10
1.95
2.00
3.33
3.43
V
3.47
22
2.020
+10
mA
V
mV
V
3.8
4.90
100
-11.0
-8.8
-7.0
1.9
4.0
4.2
160
°C
4.5
4.3
V
5.0
5.10
260
-6.0
V
mA
%
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX17031
RTC Output-Voltage Accuracy
V
RTC
RTC Short-Circuit Current
REFERENCE (REF)
Reference Voltage
Reference Load Regulation Error
REF Lockout Voltage
OUT1 FAULT DETECTION
OUT1 Overvoltage and PGOOD
Trip Threshold
OUT1 Overvoltage Fault
Propagation Delay
OUT1 Undervoltage Protection
Trip Threshold
OUT1 Output Undervoltage
Fault Propagation Delay
OUT2 FAULT DETECTION
OUT2 Overvoltage and PGOOD
Trip Threshold
OUT2 Overvoltage Fault
Propagation Delay
OUT2 Undervoltage Protection
Trip Threshold
OUT2 Output Undervoltage Fault
Propagation Delay
t
UVP
t
OVP
t
UVP
t
OVP
With respect to error comparator threshold
OUT1 forced 50mV above trip threshold
With respect to error comparator threshold
10
13
10
16
%
µs
65
70
10
75
%
µs
With respect to error comparator threshold
OUT2 forced 50mV above trip threshold
With respect to error comparator threshold
10
13
10
16
%
µs
65
70
10
75
%
µs
_______________________________________________________________________________________
3
Dual Quick-PWM Step-Down Controller with Low-
Power LDO and RTC Regulator for MAIN Supplies
MAX17031
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 2, no load on LDO5, RTC, OUT1, OUT2, and REF, V
IN
= 12V, V
DD
= V
CC
= V
SKIP
= 5V, ONLDO = RTC, ON1 = ON2
= V
CC
,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
POWER-GOOD
PGOOD Lower Trip Threshold
PGOOD Propagation Delay
PGOOD Output Low Voltage
t
PGOOD
With respect to
either
error comparator
threshold, falling edge, hysteresis = 1%
OUT1 or OUT2 forced 50mV beyond
PGOOD trip threshold, falling edge
ON1 or ON2 = GND (PGOOD low
impedance), I
SINK
= 4mA
I
PGOOD
OUT1 and OUT2 in regulation (PGOOD
high impedance), PGOOD forced to 5.5V,
T
A
= +25°C
0.2
5
R
ILIM
_ = 100k
(V
ILIM
_ = 500mV)
Valley Current-Limit Threshold
(Adjustable)
V
LIM
_
(VAL)
V
AGND
- V
LX
_
R
ILIM
_ = 200k
(V
ILIM
_ = 1.00V)
R
ILIM
_ = 400k
(V
ILIM
_ = 2.00V)
Current-Limit Threshold
(Negative)
Ultrasonic Current-Limit Threshold
Current-Limit Threshold
(Zero Crossing)
GATE DRIVERS
DH_ Gate-Driver On-Resistance
DL_ Gate-Driver On-Resistance
DH_ Gate-Driver
Source/Sink Current
DL_ Gate-Driver Source Current
DL_ Gate-Driver Sink Current
Dead Time
Internal BST_ Switch
On-Resistance
BST_Leakage Current
R
DH
R
DL
I
DH
I
DL
(SOURCE)
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
-16
-13
10
-10
%
µs
0.3
V
PGOOD Leakage Current
CURRENT LIMIT
ILIM_ Adjustment Range
ILIM_ Current
1
µA
2
V
µA
44
90
180
50
100
200
-120
20
1.5
56
110
220
%
mV
mV
mV
V
NEG
V
NEG(US)
V
ZX
With respect to valley current-limit
threshold, V
SKIP
= V
REF
V
OUT2
= 3.5V, V
OUT1
= 5.3V
V
AGND
- V
LX
_,
V
SKIP
= V
CC
or GND
BST1 - LX1 and BST2 - LX2 forced to 5V
DL1, DL2; high state
DL1, DL2; low state
DH1, DH2 forced to 2.5V,
BST1 - LX1 and BST2 - LX2 forced to 5V
DL1, DL2 forced to 2.5V
DL1, DL2 forced to 2.5V
DL1, DL2 rising (Note 4)
DH1, DH2 rising (Note 4)
I
BST
_ = 10mA, V
DD
= 5V
V
BST
_ = 26V, T
A
= +25°C;
OUT1 and OUT2 above regulation threshold
1.5
1.4
0.5
2
1.7
3.3
30
35
5.5
0.1
3.5
4.5
1.5
A
A
A
ns
I
DL (SINK)
t
DEAD
R
BST
5
µA
4
_______________________________________________________________________________________
Dual Quick-PWM Step-Down Controller with Low-
Power LDO and RTC Regulator for MAIN Supplies
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 2, no load on LDO5, RTC, OUT1, OUT2, and REF, V
IN
= 12V, V
DD
= V
CC
= V
SKIP
= 5V, ONLDO = RTC, ON1 = ON2
= V
CC
,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
INPUTS AND OUTPUTS
SKIP Input Thresholds
SKIP Leakage Current
ON_ Input-Logic Levels
ON_ Leakage Current
OUT_ Leakage Current
Upper SKIP/PWM threshold falling edge,
33mV hysteresis
Lower PWM/ultrasonic threshold
V
SKIP
= 0 or 5V, T
A
= +25°C
ONLDO, ON1, ON2
High (SMPS on)
Low (SMPS off)
-2
15
5
1.94
0.4
-1
2.4
0.8
+2
65
30
2.0
2.06
1.6
+1
µA
V
µA
µA
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX17031
V
ON1
= V
ON2
= V
ONLDO
= 0 or 5V,
T
A
= +25°C
V
ON1
= V
ON2
= V
CC
V
OUT1
= 5.3V
V
OUT2
= 3.5V
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 2, no load on LDO5, RTC, OUT1, OUT2, and REF, V
IN
= 12V, V
DD
= V
CC
= V
SKIP
= 5V, ONLDO = RTC, ON1 = ON2
= V
CC
,
T
A
= -40°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
INPUT SUPPLIES
IN Input Voltage Range
IN Standby Supply Current
IN Shutdown Supply Current
IN Supply Current
V
CC
Bias Supply Current
PWM CONTROLLERS
OUT1 Output-Voltage Accuracy
OUT2 Output-Voltage Accuracy
DH1 On-Time
DH2 On-Time
Minimum Off-Time
Ultrasonic Operating Frequency
V
OUT1
V
OUT2
t
ON1
t
ON2
t
OFF(MIN)
V
SKIP
= 1.8V
V
SKIP
= 1.8V
V
OUT1
= 5.0V (Note 1)
V
OUT2
= 3.3V (Note 1)
(Note 1)
18
4.90
3.234
895
833
5.10
3.366
1209
1017
400
V
V
ns
ns
ns
kHz
I
IN
I
VCC
LDO5 in regulation
V
IN
= 6V to 24V, ON1 = ON2 = GND,
ONLDO = RTC
V
IN
= 4.5V to 24V,
ON1 = ON2 = ONLDO = GND
ON1 = ON2 = V
CC
, V
SKIP
= V
CC
,
V
OUT1
= 5.3V, V
OUT2
= 3.5V
ON1 = ON2 = V
CC
, V
SKIP
= V
CC
,
V
OUT1
= 5.3V, V
OUT2
= 3.5V
6
24
200
70
0.2
1.5
V
µA
µA
mA
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
f
SW(USONIC)
V
SKIP
= GND
_______________________________________________________________________________________
5
Microchip MCU
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
