19-0659; Rev 1; 1/08
KIT
ATION
EVALU
BLE
AVAILA
4V to 72V Input LDOs with Boost Preregulator
General Description
The MAX5092A/MAX5092B/MAX5093A/MAX5093B low-
quiescent-current, low-dropout (LDO) regulators contain
simple boost preregulators operating at a high frequency.
The devices seamlessly provide a preset 3.3V
(MAX5092A/MAX5093A) or 5V (MAX5092B/MAX5093B)
LDO output voltage from an automotive cold-crank
through load-dump (3.5V to 80V) input voltage condi-
tions. The MAX5092_/MAX5093_ deliver up to 250mA
with excellent load and line regulation. During normal
operation, when the battery is healthy, the boost preregu-
lator is completely turned off, reducing quiescent current
to 65µA (typ). This makes the devices suitable for
always-on power supplies.
The buck-boost operation achieved by this combination
of LDO and boost preregulator offers the advantage of
using a single off-the-shelf inductor in place of the mul-
tiple-winding custom magnetics needed in typical sin-
gle-ended primary inductor converter (SEPIC) and
transformer-based flyback topologies. The high operat-
ing frequency of the boost regulator significantly
reduces component size. The MAX5092_ integrates a
blocking diode to further reduce the external compo-
nent count. The boost preregulator output voltage is
preset to 7V. Both LDO and boost output voltages are
programmable using external resistors. The boost pre-
regulator output voltage is adjustable up to 11V
(MAX5092_), or up to 12V (MAX5093_). The LDO output
voltage is adjustable from 1.5V to 9V (MAX5092_) or
from 1.5V to 10V (MAX5093_).
The devices feature a shutdown mode with 5µA (typ)
shutdown current, a
HOLD
input to implement a self-hold-
ing circuit, and a power-on-reset output (RESET) with an
externally programmable timeout period. Additional fea-
tures include output overload, short-circuit, and thermal
protection.
The MAX5092_/MAX5093_ are available in a thermally
enhanced, 16-pin 5mm x 5mm thin QFN package and
can dissipate up to 2.7W at +70°C on a multilayer PC
board (PCB).
Features
o
Wide Operating Input Voltage Range: 3.5V to 72V
with a 4V Startup Voltage
o
LDO Output Regulates to 5V Seamlessly from an
Input Voltage of 3.5V to 72V
o
Up to 250mA Output Current
o
Preset 3.3V, 5V, or Externally Programmable LDO
Output Voltage from 1.5V to 9V (MAX5092_) or
from 1.5V to 10V (MAX5093_)
o
Preset 7V or Externally Programmable Boost
Output Voltage Up to 11V (MAX5092_) or Up to
12V (MAX5093_)
o
65µA Quiescent Current in LDO Mode (V
IN
≥8V)
o
5µA Shutdown Current
o
Power-On Reset (RESET) with Programmable
Timeout Period
o
Output Short-Circuit and Thermal Protection
o
TQFN Package Capable of Dissipating Up to 2.7W
at +70°C
MAX5092/MAX5093
Ordering Information
PART
MAX5092AATE+
MAX5092BATE+
MAX5093AATE+
MAX5093BATE+
TEMP RANGE
PIN-
PACKAGE
PKG
CODE
T1655-3
T1655-3
T1655-3
T1655-3
-40°C to +125°C 16 TQFN-EP*
-40°C to +125°C 16 TQFN-EP*
-40°C to +125°C 16 TQFN-EP*
-40°C to +125°C 16 TQFN-EP*
+Denotes
lead-free package.
*EP
= Exposed pad.
Pin Configuration
PGND_BST
TOP VIEW
12
11
10
BSOUT
9
LX
LX
BSFB 13
VL 14
CT 15
RESET 16
8
7
OUT
OUT_SENSE
SET
PGND_LDO
Applications
Automotive—Body Electronics
Automotive—ECU
Industrial
MAX5092_/
MAX5093_
+
1
IN
2
EN
3
SGND
4
HOLD
6
5
Typical Operating Circuit and Selector Guide appear at end
of data sheet.
THIN QFN
(5mm x 5mm)
________________________________________________________________
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.
4V to 72V Input LDOs with Boost Preregulator
MAX5092/MAX5093
ABSOLUTE MAXIMUM RATINGS
IN, EN, LX, BSOUT to SGND..................................-0.3V to +80V
PGND_BST, PGND_LDO to SGND .......................-0.3V to +0.3V
RESET,
OUT, OUT_SENSE to SGND .....................-0.3V to +12V
BSOUT to LX (MAX5092_)......................................-0.3V to +12V
VL, SET, BSFB, SGND..............................................-0.3V to +6V
HOLD
to SGND….....................................-0.3V to (V
OUT
+ 0.3V)
CT to SGND.................................................-0.3V to (V
VL
+ 0.3V)
OUT Current (I
OUT
) Short Circuit to PGND_LDO,
(V
IN
≤
28V) ..............................................................Continuous
Note 1:
As per JEDEC Standard 51 (Multilayer Board).
RESET
Sinking Current .........................................................5mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin Thin QFN (derate 33.3mW/°C
above +70°C)...............................................2666mW (Note 1)
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
= V
EN
= 14V, I
OUT
= 1mA, C
IN
= 47µF, C
BSOUT
= 22µF, C
OUT
= 10µF, C
VL
= 1µF, T
A
= T
J
= -40°C to +125°C, unless otherwise
noted. See Figures 4–7 as applicable. Typical specifications are at T
A
= +25°C.) (Note 2)
PARAMETER
INPUT SUPPLY
Input Voltage Range
Internal Input Undervoltage
Lockout
Supply Current (Boost Converter
Off)
Supply Current (Boost Converter
On)
Shutdown Supply Current
BOOST CONVERTER
Minimum BSOUT Output Current
Boost Converter Enable
Threshold
Boost Converter Disable
Threshold
Boost Converter Disable
Hysteresis
BSOUT Output Voltage
Maximum BSOUT Output Voltage
BSFB Regulation Voltage
BSFB Input Bias Current
Boost Internal Switch
On-Resistance
Boost Internal Switch Minimum
Off-Time
I
BSOUT
V
BST_EN
V
BST_DIS
V
BST_HYS
V
BSOUT
V
BSOUT(MAX)
V
BSFB
I
BSFB
R
DS(ON)
t
OFF
0.80
0.5
1
V
IN
= 4V, BSFB = SGND, V
OUT
= 5V
MAX5092_
MAX5093_
1.18
V
IN
= 4V
V
BSOUT –
V
OUT
falling (Note 5)
V
BSOUT –
V
OUT
rising (Note 5)
1.7
2.2
250
2.0
2.5
0.5
7.00
11
12
1.24
1.30
100
1.2
1.25
2.3
2.8
mA
V
V
V
V
V
V
nA
Ω
µs
V
IN
V
UVLOF
V
UVLOR
I
Q
(Note 3)
V
IN
falling
V
IN
rising
LDO mode,
I
OUT
= 100µA
T
J
= -40°C to +125°C
(Note 4)
4
3.0
3.4
3.2
3.6
65
70
0.4
T
J
= -40°C to +125°C
(Note 4)
6
72
3.4
3.8
85
100
1.0
10
mA
µA
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
µA
LDO mode, I
OUT
= 250mA
I
S
I
SHDN
V
IN
= 5V
V
EN
≤
+0.4V
2
_______________________________________________________________________________________
4V to 72V Input LDOs with Boost Preregulator
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
EN
= 14V, I
OUT
= 1mA, C
IN
= 47µF, C
BSOUT
= 22µF, C
OUT
= 10µF, C
VL
= 1µF, T
A
= T
J
= -40°C to +125°C, unless otherwise
noted. See Figures 4–7 as applicable. Typical specifications are at T
A
= +25°C.) (Note 2)
PARAMETER
Boost Internal Switch Maximum
On-Time
Internal Switch Current Limit
Boost Turn-On Response Time
Internal Diode Forward Voltage
Drop
LDO
Guaranteed Output Current
I
OUT
V
BSOUT
- V
OUT
= 2V (Note 6)
SET = SGND,
MAX5092A/
MAX5093A
Output Voltage
V
OUT
SET = SGND,
MAX5092B/
MAX5093B
Minimum Adjustable Output
Voltage
Maximum Adjustable Output
Voltage
V
ADJMIN
I
OUT
= 1mA
100µA
≤
I
OUT
≤
250mA
I
OUT
= 1mA
100µA
≤
I
OUT
≤
250mA
250
3.25
3.2
4.900
4.85
3.3
3.3
5
5
1.5
9
V
10
1.5
0.9
200
0.4
0.5
1.6
1.205
1.235
0.5
I
OUT
= 1mA to 250mA
f = 100Hz
Power-Supply Rejection Ratio
PSRR
f = 1MHz
Short-Circuit Current
I
SC
I
OUT
= 10mA, V
BSOUT(AC)
= 500mV
P-P
, V
OUT
= 5V
I
OUT
= 10mA, V
BSOUT(AC)
= 500mV
P-P
, V
OUT
= 5V
255
0.2
80
dB
60
490
mA
1.265
100
0.6
V
nA
mV/mA
mV/V
10.0
1.6
V
V
µs
3.35
3.4
5.075
5.10
V
V
mA
V
F
SYMBOL
t
ON-MAX
I
LIM
Measured in steady-state condition
Time from V
BSOUT
falling below regulation
to switch on-time
MAX5092_ only, I
F
= 1A
CONDITIONS
MIN
1.80
1.5
2
0.95
TYP
2.25
MAX
2.70
3.0
5
UNITS
µs
A
µs
V
MAX5092/MAX5093
Boost operation, V
IN
= 4V, V
BSOUT
= 7V
MAX5092_,
V
BSOUT
= 11V
MAX5093_,
V
BSOUT
= 12V
V
ADJMAX
Boost operation,
V
IN
= 4V
Adjustable Output Voltage
Dropout Voltage
LDO Startup Response Time
V
ADJ
ΔV
DO
LDO operation, V
IN
≥
V
BST_DIS
(boost converter off) (Note 7)
I
OUT
= 250mA (Note 8)
Rising edge of V
BSOUT
to the rising edge of
V
OUT
, R
L
= 500Ω, SET = SGND
Line Regulation
SET Reference Voltage
SET Input Bias Current
Load Regulation
ΔV
OUT
/
ΔV
IN
V
SET
I
SET
ΔV
OUT
/
ΔI
OUT
7V
≤
V
IN
≤
72V,
I
LOAD
= 10mA
MAX5092A/MAX5093A
MAX5092B/MAX5093B
7V
≤
V
IN
≤
28V, I
LOAD
= 250mA
_______________________________________________________________________________________
3
4V to 72V Input LDOs with Boost Preregulator
MAX5092/MAX5093
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
EN
= 14V, I
OUT
= 1mA, C
IN
= 47µF, C
BSOUT
= 22µF, C
OUT
= 10µF, C
VL
= 1µF, T
A
= T
J
= -40°C to +125°C, unless otherwise
noted. See Figures 4–7 as applicable. Typical specifications are at T
A
= +25°C.) (Note 2)
PARAMETER
ENABLE,
HOLD
and
RESET
EN High Input Threshold
EN Low Input Threshold
EN Input Bias Current
HOLD
Low Input Threshold
HOLD
Release Voltage
HOLD
Pullup Current
RESET
Voltage Threshold
RESET
Threshold Hysteresis
RESET
Output Low Voltage
RESET
Output High Leakage
Current
RESET
Output Minimum Timeout
Period
EN to
RESET
Minimum Timeout
Delay
Delay Comparator Threshold
(Rising)
Delay Comparator Threshold
Hysteresis
CT Charge Current
CT Discharge Current
Thermal Shutdown Temperature
Threshold
Thermal Shutdown Temperature
Hysteresis
V
CTTH
V
CTTH-HYS
I
CT-CHG
I
CT-DIS
T
J(SHDN)
T
J(HYST)
Temperature rising
1.5
EN
H
EN
L
I
EN
V
IL
V
IH
I
HOLD
V
RESET
V
RHYST
V
RL
I
RH
Regulator on, EN transition from high to low
EN = low
Internally connected to OUT
% of V
OUT
, V
OUT
falling
% of V
OUT
I
SINK
= 1mA
V
R ESE
T
= 5V
C
CT
not connected
C
CT
not connected
1.205
25
260
1.24
100
2
5
165
20
2.5
1.265
87
V
OUT
-
0.4
4
90
2
0.4
1
92
0.25
2.4
0.4
2
0.4
V
V
µA
V
V
µA
%
%
V
µA
µs
µs
V
mV
µA
mA
°C
°C
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Limits at -40°C are guaranteed by design and characterization; not production tested.
Guaranteed minimum operating voltage is 3.5V on V
IN
falling only.
Guaranteed by design and not production tested.
The boost converter disable threshold (V
BST_DIS
) is a static measurement. Internal comparator delay may cause a higher
disable level.
Note 6:
The continuous maximum output current from the LDO is guaranteed according to the maximum power dissipation imposed
by the package thermal constraints.
Note 7:
Maximum output adjustable value is conditioned by the maximum adjustable BSOUT Output Voltage Range minus the maxi-
mum dropout across the pass transistor.
Note 8:
Dropout voltage is defined as (V
BSOUT
- V
OUT
) when V
OUT
is 2% below the value of V
OUT
for V
BSOUT
= V
OUT
+ 2V.
Note 2:
Note 3:
Note 4:
Note 5:
4
_______________________________________________________________________________________
4V to 72V Input LDOs with Boost Preregulator
Typical Operating Characteristics
(V
IN
= V
EN
= 14V, C
IN
= 47µF, C
BSOUT
= 22µF, C
OUT
= 10µF, C
VL
= 1µF, T
A
= +25°C, unless otherwise noted.) (See Figures 4–7 as
applicable.)
QUIESCENT SUPPLY CURRENT
vs. INPUT VOLTAGE (MAX5092B)
MAX5092/93 toc01
MAX5092/MAX5093
INPUT CURRENT (I
IN
)
vs. INPUT VOLTAGE (MAX5092B)
MAX5092/93 toc02
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE (MAX5092B)
BOOST CONVERTER NOT SWITCHING,
QUIESCENT SUPPLY CURRENT = I
IN
- I
OUT
MAX5092/93 toc03
90
QUIESCENT SUPPLY CURRENT (μA)
85
80
75
70
65
60
55
50
8
16
24
32
40
48
56
64
BOOST CONVERTER NOT SWITCHING,
QUIESCENT SUPPLY CURRENT = I
IN
- I
OUT
I
OUT
= 10mA
I
OUT
= 100μA
100
I
OUT
= 10mA
INPUT CURRENT (mA)
10
100
QUIESCENT SUPPLY CURRENT (μA)
90
80
I
OUT
= 10mA
70
60
50
40
1
I
OUT
= 100μA
I
OUT
= 100μA
BOOST CONVERTER SWITCHING
0.1
4.0
4.5
5.0
5.5
6.0
6.5
7.0
INPUT VOLTAGE (V)
-40
-15
10
35
60
85
110
135
72
INPUT VOLTAGE (V)
TEMPERATURE (°C)
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE (MAX5093B)
MAX5092/93 toc04
SHUTDOWN SUPPLY CURRENT
vs. INPUT VOLTAGE (MAX5092B)
MAX5092/93 toc05
SHUTDOWN SUPPLY CURRENT
vs. INPUT VOLTAGE (MAX5093B)
SHUTDOWN SUPPLY CURRENT (μA)
MAX5092/93 toc06
100
QUIESCENT SUPPLY CURRENT (μA)
90
80
70
60
50
40
-40
-15
10
35
60
85
110
I
OUT
= 100μA
I
OUT
= 10mA
BOOST CONVERTER NOT SWITCHING,
QUIESCENT SUPPLY CURRENT = I
IN
- I
OUT
10
SHUTDOWN SUPPLY CURRENT (μA)
10
8
8
6
6
4
4
2
V
EN
= 0V
0
2
V
EN
= 0V
0
135
4
14
24
34
44
54
64
74
4
14
24
34
44
54
64
74
TEMPERATURE (°C)
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE (MAX5092B)
MAX5092/93 toc07
SWITCHING WAVEFORMS
V
BSOUT
PROGRAMMED < (V
OUT
+ V
BST_DIS
)
MAX5092/93 toc08
10
SHUTDOWN SUPPLY CURRENT (μA)
V
IN
1V/div
V
BSOUT
2V/div
5V
(AC-COUPLED)
8.5V
(AC-COUPLED)
8
6
V
OUT
100mV/div
4
V
EN
= 0V
2
-40
-15
10
35
60
85
110
135
TEMPERATURE (°C)
I
LX
2A/div
100μs/div
5V
(AC-COUPLED)
V
IN
= 5V, I
OUT
= 100mA,
V
BSOUT
PROGRAMMED TO 11V
0
_______________________________________________________________________________________
5
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