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KIT
ATION
EVALU
BLE
AVAILA
1A, 4.5V to 40V Input Buck Converters with
50mA Auxiliary LDO Regulators
General Description
The MAX15014–MAX15017 combine a step-down DC-
DC converter and a 50mA, low-quiescent-current low-
dropout (LDO) regulator. The LDO regulator is ideal for
powering always-on circuitry in automotive applications.
The DC-DC converter input voltage range is 4.5V to 40V
for the MAX15015/MAX15016, and 7.5V to 40V for the
MAX15014/MAX15017.
The DC-DC converter output is adjustable from 1.26V to
32V and can deliver up to 1A of load current. These
devices utilize a feed-forward voltage-mode control
scheme for good noise immunity in the high-voltage
switching environment and offer external compensation
allowing for maximum flexibility with a wide selection of
inductor values and capacitor types. The switching
frequency is internally fixed at 135kHz and 500kHz,
depending on the version chosen. Moreover, the
switching frequency can be synchronized to an exter-
nal clock signal through the SYNC input. Light load effi-
ciency is improved by automatically switching to a
pulse-skip mode. The soft-start time is adjustable with
an external capacitor. The DC-DC converter can be
disabled independent of the LDO, thus reducing the
quiescent current to 47µA (typ).
The LDO linear regulators operate from 5V to 40V and
deliver a guaranteed 50mA load current. The devices
feature a preset output voltage of 5V (MAX1501_A) or
3.3V (MAX1501_B). Alternatively, the output voltage
can be adjusted from 1.5V to 11V by using an external
resistive divider. The LDO section also features a
RESET
output with adjustable timeout period.
Protection features include cycle-by-cycle current limit,
hiccup-mode output short-circuit protection, and thermal
shutdown. All devices are available in a space-saving,
high-power (2.86W), 36-pin TQFN package and are
rated for operation over the -40°C to +125°C automotive
temperature range.
Features
o
Combined DC-DC Converters and Low-Quiescent-
Current LDO Regulators
o
1A DC-DC Converters Operate from 4.5V to 40V
(MAX15015/MAX15016) or 7.5V to 40V
(MAX15014/MAX15017)
o
Switching Frequency of 135kHz
(MAX15014/MAX15016) or 500kHz
(MAX15015/MAX15017)
o
50mA LDO Regulator Operates from 5V to 40V
Independent of the DC-DC Converter
o
47µA Quiescent Current with DC-DC Converter
Off and LDO On
o
6µA System Shutdown Current
o
Frequency Synchronization Input
o
Shutdown/Enable Inputs
o
Adjustable Soft-Start Time
o
Active-Low Open-Drain
RESET
Output with
Programmable Timeout Delay
o
Thermal Shutdown and Output Short-Circuit
Protection
o
Space-Saving (6mm x 6mm) Thermally Enhanced
36-Pin TQFN Package
MAX15014–MAX15017
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
PKG
CODE
T3666-3
T3666-3
T3666-3
T3666-3
T3666-3
T3666-3
T3666-3
T3666-3
MAX15014AATX+
-40°C to +125°C 36 TQFN-EP*
MAX15014BATX+
MAX15015BATX+
MAX15016BATX+
MAX15017BATX+
-40°C to +125°C 36 TQFN-EP*
-40°C to +125°C 36 TQFN-EP*
-40°C to +125°C 36 TQFN-EP*
-40°C to +125°C 36 TQFN-EP*
MAX15015AATX+
-40°C to +125°C 36 TQFN-EP*
MAX15016AATX+
-40°C to +125°C 36 TQFN-EP*
Applications
Car Radios
Automotive Body Control Modules
Automotive Instrument Cluster
Navigation Systems
MAX15017AATX+
-40°C to +125°C 36 TQFN-EP*
+Denotes
a lead-free package.
*EP
= Exposed pad.
________________________________________________________________
Maxim Integrated Products
1
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.
1A, 4.5V to 40V Input Buck Converters with
50mA Auxiliary LDO Regulators
MAX15014–MAX15017
ABSOLUTE MAXIMUM RATINGS
IN_SW, IN_LDO, DRAIN, EN_SYS, EN_SW
to SGND ..............................................................-0.3V to +45V
IN_LDO to IN_SW ..................................................-0.3V to +0.3V
LX to SGND ...........................................-0.3V to (V
IN_SW
+ 0.3V)
LX to PGND ...........................................-0.3V to (V
IN_SW
+ 0.3V)
BST to SGND ..........................................-0.3V to (V
IN_SW
+ 12V)
BST to LX................................................................-0.3V to +12V
PGND to SGND .....................................................-0.3V to +0.3V
REG, DVREG, SYNC,
RESET,
CT to SGND............-0.3V to +12V
FB, COMP_SW, SS to SGND....................-0.3V to (V
REG
+ 0.3V)
SET_LDO, LDO_OUT to SGND ..............................-0.3V to +12V
C+ to PGND
(MAX15015/MAX15016 only)................(V
DVREG
- 0.3V) to 12V
C- to PGND
(MAX15015/MAX15016 only) ............-0.3V to (V
DVREG
+ 0.3V)
LDO_OUT Output Current.................................Internally Limited
Switch DC Current (DRAIN and LX pins combined)
T
J
= +125°C.......................................................................1.9A
T
J
= +150°C.....................................................................1.25A
RESET
Sink Current ..............................................................5mA
Continuous Power Dissipation (T
A
= +70°C)
36-Pin TQFN (derate 26.3mW/°C above +70°C)
Single-Layer Board .....................................................2105mW
36-Pin TQFN (derate 35.7mW/°C above +70°C)
Multilayer Board ..........................................................2857mW
Operating Temperature Range .........................-40°C to +125°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range ............................-60°C to +150°C
Lead Temperature (soldering, 10s) ................................+300°C
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.
ELECTRICAL CHARACTERISTICS
(V
IN_SW
= V
IN_LDO
= V
DRAIN
= 14V, V
EN_SYS
= V
EN_SW
= 2.4V, V
REG
= V
DVREG
, V
SYNC
= V
SET_LDO
= V
SGND
= V
PGND
= 0V, C
REG
=
1µF, C
IN_SW
= 0.1µF, C
IN_LDO
= 0.1µF, C
LDO_OUT
= 10µF, C
DRAIN
= 0.22µF, T
A
= T
J
= -40°C to +125°C, unless otherwise noted.
Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
System Supply Current (Not
Switching)
SYMBOL
CONDITIONS
V
FB
= 1.3V,
MAX15014/MAX15017
I
SYS
No load
V
FB
= 1.3V,
MAX15015/MAX15016
V
FB
= 0V,
MAX15014/MAX15017
Switching System Supply Current
I
SW
No load
V
FB
= 0V,
MAX15015/MAX15016
V
EN_SYS
= 14V,
V
EN_SW
= 0V
I
LDO_OUT
= 100µA
I
LDO_OUT
= 50mA
8.6
47
130
6
2.4
0.8
220
I
EN_SYS
V
EN_SYS
= 2.4V
V
EN_SYS
= 14V
MAX15014/MAX15017
MAX15015/MAX15016
7.5
4.5
0.5
0.6
2
2
40.0
40.0
63
200
10
µA
V
mV
µA
0.85
5.6
mA
1.8
MIN
TYP
0.7
MAX
1.8
mA
UNITS
LDO Quiescent Current
System Shutdown Current
System Enable Voltage
System Enable Hysteresis
System Enable Input Current
BUCK CONVERTER
Input Voltage Range
I
LDO
I
SHDN
V
EN_SYSH
V
EN_SYSL
µA
V
EN_SYS
= 0V, V
EN_SW
= 0V
EN_SYS = high, system on
EN_SYS = low, system off
V
IN_SW
V
2
_______________________________________________________________________________________
1A, 4.5V to 40V Input Buck Converters with
50mA Auxiliary LDO Regulators
ELECTRICAL CHARACTERISTICS (continued)
(V
IN_SW
= V
IN_LDO
= V
DRAIN
= 14V, V
EN_SYS
= V
EN_SW
= 2.4V, V
REG
= V
DVREG
, V
SYNC
= V
SET_LDO
= V
SGND
= V
PGND
= 0V, C
REG
=
1µF, C
IN_SW
= 0.1µF, C
IN_LDO
= 0.1µF, C
LDO_OUT
= 10µF, C
DRAIN
= 0.22µF, T
A
= T
J
= -40°C to +125°C, unless otherwise noted.
Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
V
IN_SW
and IN_LDO rising,
MAX15014/MAX15017
V
IN_SW
and IN_LDO rising,
MAX15015/MAX15016
MAX15014/MAX15017
MAX15015/MAX15016
Minimum output
Maximum output
EN_SW = high, switching power supply is on
EN_SW = low, switching power supply is off
220
I
EN_SW
V
EN_SW
= 2.4V
V
EN_SW
= 14V
MAX15014/MAX15017, V
IN_SW
= 9V to 40V
Output Voltage
V
REG
MAX15015/MAX15016,
V
IN_SW
= 5.5V to 40V
V
IN_SW
= 9.0V to 40V, MAX15014/MAX15017
V
IN_SW
= 5.5V to 40V, MAX15015/MAX15016
I
REG
= 0 to 20mA
V
IN_SW
= 7.5V (MAX15014/MAX15017),
V
IN_SW
= 4.5V (MAX15015/MAX15016),
I
REG
= 20mA
V
SYNC
= 0V, MAX15014/MAX15016
V
SYNC
= 0V, MAX15015/MAX15017
V
SYNC
= 0V, V
IN_SW
= 7.5V, MAX15014
(135kHz)
V
SYNC
= 0V, V
IN_SW
= 4.5V, MAX15016
(135kHz)
Maximum Duty Cycle
D
MAX
V
SYNC
= 0V, V
IN_SW
= 4.5V, MAX15015
(500kHz)
V
SYNC
= 0V, V
IN_SW
= 7.5V, MAX15017
(500kHz)
Minimum LX Low Time
SYNC High-Level Voltage
SYNC Low-Level Voltage
V
SYNC
= 0V
122
425
90
90
90
90
94
2.2
0.8
136
500
7.6
4.75
1
1
0.25
0.5
0.5
0.6
2
2
8.4
5.25
V
2.4
0.8
MIN
6.7
3.90
TYP
7.0
4.08
0.54
0.3
1.26
32
1
MAX
7.4
V
4.25
V
V
A
V
mV
µA
UNITS
MAX15014–MAX15017
Undervoltage Lockout Threshold
UVLO
TH
Undervoltage Lockout
Hysteresis
Output Voltage Range
Output Current
EN_SW Input Voltage Threshold
EN_SW Hysteresis
Switching Enable Input Current
UVLO
HYST
V
OUT
I
OUT
V
EN_SWH
V
EN_SWL
INTERNAL VOLTAGE REGULATOR
Line Regulation
Load Regulation
Dropout Voltage
OSCILLATOR
Frequency Range
f
CLK
mV/V
V
V
150
575
98
98
kHz
%
96
98
ns
V
_______________________________________________________________________________________
3
1A, 4.5V to 40V Input Buck Converters with
50mA Auxiliary LDO Regulators
MAX15014–MAX15017
ELECTRICAL CHARACTERISTICS (continued)
(V
IN_SW
= V
IN_LDO
= V
DRAIN
= 14V, V
EN_SYS
= V
EN_SW
= 2.4V, V
REG
= V
DVREG
, V
SYNC
= V
SET_LDO
= V
SGND
= V
PGND
= 0V, C
REG
=
1µF, C
IN_SW
= 0.1µF, C
IN_LDO
= 0.1µF, C
LDO_OUT
= 10µF, C
DRAIN
= 0.22µF, T
A
= T
J
= -40°C to +125°C, unless otherwise noted.
Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
SYNC Frequency Range
Ramp Level Shift (Valley)
ERROR AMPLIFER
Soft-Start Reference Voltage
Soft-Start Current
FB Regulation Voltage
FB Input Range
FB Input Current
COMP Voltage Range
Open-Loop Gain
Unity-Gain Bandwidth
PWM Modulator Gain
CURRENT-LIMIT COMPARATOR
Pulse Skip Threshold
Cycle-by-Cycle Current Limit
Number of Consecutive ILIM
Events to Hiccup
Hiccup Timeout
POWER SWITCH
Switch On-Resistance
Switch Gate Charge
Switch Leakage Current
BST Quiescent Current
BST Leakage Current
CHARGE PUMP (MAX15015/MAX15016)
C- Output Voltage Low
C- Output Voltage High
DVREG to C+ On-Resistance
LX to PGND On-Resistance
LDO
Input Voltage Range
Undervoltage Lockout Threshold
Undervoltage Lockout Hysteresis
V
IN_LDO
UVLO_LDO
TH
UVLO_LDO
HYST
V
IN_LDO
rising
5
3.90
4.1
0.3
40
4.25
V
V
V
Sinking 10mA
Relative to DVREG, sourcing 10mA
Sourcing 10mA
Sinking 10mA
0.1
0.1
10
12
V
V
Ω
Ω
V
BST
- V
LX
= 6V
V
BST
- V
LX
= 6V
V
IN_SW
= V
IN_LDO
= V
LX
= V
DRAIN
=
40V, V
FB
= 0V
V
BST
= 40V, V
DRAIN
= 40V, V
FB
= 0V,
DVREG = 5V
V
BST
= V
DRAIN
= V
LX
= V
IN_SW
=
V
IN_LDO
= 40V, EN_SW = 0V
400
0.15
0.4
4
10
600
1
0.80
Ω
nC
µA
µA
µA
IPFM
I
ILIM
100
1.3
200
2
7
512
300
2.6
mA
A
—
Clock
periods
f
SYNC
= 500kHz, MAX15015/MAX15017
f
SYNC
= 135kHz, MAX15014/MAX15016
V
SS
I
SS
V
FB
V
FB
I
FB
V
FB
= 1.244V
I
COMP
= -500µA to +500µA
V
SS
= 0V
1.210
7
1.210
0
-250
0.25
80
1.8
10
10
1.235
12
1.235
1.260
17
1.260
1.5
+250
4.5
V
µA
V
V
nA
V
dB
MHz
V/V
SYMBOL
f
SYNC
CONDITIONS
MAX15014/MAX15016
MAX15015/MAX15017
MIN
100
400
0.3
TYP
MAX
200
600
UNITS
kHz
V
4
_______________________________________________________________________________________
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