General Description
The MAX5023/MAX5024 high-voltage linear regulators
operate from a +6.5V to +65V input voltage and deliver up
to 150mA of output current. These devices consume only
60μA of quiescent current with no load and withstand a
-60V reverse-battery voltage at the input. The MAX5023/
MAX5024 include an active-low internal microprocessor
(μP) reset circuit that asserts when the regulator output
drops below the preset output voltage threshold by 7.5% or
12.5%, depending on the device selected. Both devices are
available with a fixed +3.3V or +5V output. These devices
are short-circuit protected and include thermal shutdown.
In addition to an enable input to turn on or off the regula-
tor, the MAX5023/MAX5024 include a HOLD input that
allows for the implementation of a self-holding circuit
without requiring external components. Setting HOLD low
after enabling the regulator, forces the regulator to remain
on even if EN is subsequently set low. Releasing HOLD
shuts down the regulator.
The MAX5023 includes a watchdog input that monitors a
pulse train from the μP and generates reset pulses if the
watchdog input remains high or low for a duration longer
than the 1.6s watchdog timeout period. The MAX5024
includes a SET input which, when connected to ground,
selects a preset output voltage of +3.3V (MAX5024S/
MAX5024T) or +5V (MAX5024L/MAX5024M). Set the
adjustable output voltage by connecting SET to the
regulator’s output through a resistive-divider network.
The MAX5023/MAX5024 operate over the automotive
temperature range (-40°C to +125°C) and are available in a
thermally enhanced, surface-mount 8-pin SO-EP package.
Applications
Automotive
Industrial
Home Security
Fire/Smoke Alarms
Telecom/Networking
Features
Wide Operating Input Voltage Range +6.5V to +65V
Thermally Enhanced 8-Pin SO Package with
Exposed Pad Dissipates 1.5W
Guaranteed 150mA Output Current
60μA No-Load Supply Current
-60V Reverse-Battery Protection
Preset +3.3V or +5.0V Output Voltage
Thermal and Short-Circuit Protection
Operate Over -40°C to +125°C Temperature Range
Integrated μP Reset Circuit
Watchdog Timer with 1.6s Timeout Period
(MAX5023)
Regulator Enable and Hold Inputs Implement Self-
Holding Circuit
SET Input for Adjustable Output Voltage (MAX5024)
Selector Guide and Ordering Information appear at end of
data sheet.
19-2619; Rev 8; 3/16
IN
EN
GND
HOLD
VCC
I/OWDI
RESET
OUT
RESET
µP
15µF
10k
+6.5V TO +65V
I/O
ON
OFF
IGNITION
SWITCH
MAX5023
10µF
Typical Operating Circuit
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
IN to GND ............................................................... -60V to +70V
EN to GND .................................................-0.3V to (VIN + 0.3V)
HOLD to GND ........................................ -0.3V to (VOUT + 0.3V)
SET, WDI, OUT to GND .....................................-0.3V to +13.2V
RESET to GND (Open Drain) ............................-0.3V to +13.2V
Short-Circuit Duration (VIN +14V) ..........................Continuous
Maximum Current to Any Pin (Except IN, OUT) ..............±20mA
Continuous Power Dissipation (TA = +70°C)
8-Pin SO-EP (derate 19.2mW/°C above +70°C) ....... 1538mW
Operating Temperature Range ......................... -40°C to +125°C
Junction Temperature ...................................................... +150°C
Storage Temperature Range ............................ -65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
(Note 1)
SO-EP
Junction-to-Ambient Thermal Resistance (θJA) ...........41°C/W
Junction-to-Case Thermal Resistance JC)..................2°C/W
(VIN = +14V, IOUT = 1mA, CIN = 10μF, COUT = 15μF, VEN = +2.4V, HOLD = open, 10kΩ from RESET to OUT, TA = -40°C to +125°C,
unless otherwise noted. Typical specifications are at TA = +25°C.) (Note 2)
Absolute Maximum Ratings
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
Package Thermal Characteristics
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Voltage Range VIN VIN must be at least 1.5V greater than VOUT 6.5 65 V
Reverse Input Current IREVERSE VIN = -60V 0.1 10 µA
Supply Current IQMeasured at GND IOUT = 0mA 58 140 µA
IOUT = 150mA 2000
Shutdown Supply Current ISHDN VEN ≤ +0.4V 6 16 µA
REGULATOR
Guaranteed Output Current IOUT VOUT = +5V 150 mA
Output Voltage VOUT
SET = GND, IOUT = 1mA to 150mA,
5V version 4.8 5 5.2
V
SET = GND, IOUT = 1mA to 150mA,
3.3V version 3.168 3.3 3.432
IOUT = 5mA, adjustable version (MAX5024) 2.5 11
Dropout Voltage ΔVDO ILOAD = 150mA, VOUT = +5V (Note 3) 0.9 1.5 V
Startup Response Time Rising edge of VIN to VOUT, RL = 500Ω,
SET = GND 400 µs
Line Regulation ΔVOUT/
ΔVIN +8V ≤ VIN ≤ +65V +5V version -1 +1 mV/V
+3.3V version -0.5 0.5
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
www.maximintegrated.com Maxim Integrated
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(VIN = +14V, IOUT = 1mA, CIN = 10μF, COUT = 15μF, VEN = +2.4V, HOLD = open, 10kΩ from RESET to OUT, TA = -40°C to +125°C,
unless otherwise noted. Typical specifications are at TA = +25°C.) (Note 2)
Electrical Characteristics (continued)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Enable Voltage VEN
EN = high, regulator on 2.4 V
EN = low, regulator off 0.4
Enable Input Current IEN
VEN = +2.4V 0.5 µA
VEN = +14V 4
HOLD Voltage VIL Regulator on, EN transition from high to low 0.4 V
HOLD Release Voltage VIH EN = low, regulator shuts off VOUT - 0.4V V
HOLD Pullup Current IHOLD Internally connected to OUT 4 µA
SET Reference Voltage VSET IOUT = 10mA 1.223 1.248 1.273 V
SET Input Leakage Current ISET 0.5 100 nA
Load Regulation ΔVOUT/
ΔIOUT IOUT = 1mA to 150mA 1 mV/mA
Power-Supply Rejection Ratio PSRR IOUT = 10mA, f = 100Hz, 500mVP-P,
VOUT = +5V 54 dB
Short-Circuit Current ISC VIN = +8V 175 300 mA
Thermal-Shutdown
Temperature TJ(SHDN) 150 °C
Thermal-Shutdown Hysteresis ΔTJ(SHDN) 20 °C
RESET CIRCUIT
Reset Threshold VTH
MAX502_L, SET = GND 4.50 4.625 4.75
V
MAX502_M, SET = GND 4.25 4.375 4.50
MAX502_T, SET = GND 2.970 3.052 3.135
MAX502_S, SET = GND 2.805 2.887 2.970
MAX5024L/T, SET = Divider
(Figure 1) (Note 4) 0.925 x VOUT
MAX5024M/S, SET = Divider
(Figure 1) (Note 4) 0.875 x VOUT
Reset Timeout Period tRP 140 200 260 ms
VOUT to Reset Delay tRD VOUT falling 5 µs
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
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Note 2: Limits at -40°C are guaranteed by characterization and not production tested.
Note 3: Dropout voltage is defined as VIN - VOUT when VOUT is 100mV below the value of VOUT for VIN = VOUT + 3V.
Note 4: VOUT = VSET (1 + R1/R2) = 1.248V (1 + R1/R2).
Note 5: RESET is guaranteed to be in the correct logic state for VOUT > +1V.
Note 6: Guaranteed by design, not production tested.
(VIN = +14V, CIN = 10μF, COUT = 15μF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specied.)
(VIN = +14V, IOUT = 1mA, CIN = 10μF, COUT = 15μF, VEN = +2.4V, HOLD = open, 10kΩ from RESET to OUT, TA = -40°C to +125°C,
unless otherwise noted. Typical specifications are at TA = +25°C.) (Note 2)
Typical Operating Characteristics
Electrical Characteristics (continued)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Open-Drain RESET Output
Voltage (Note 5) VOL
VOUT ≥ +1.0V, ISINK = 50µA,
RESET asserted 0.3
V
VOUT ≥ +2.85V, ISINK = 1.2mA,
RESET asserted 0.3
VOUT ≥ +4.25V, ISINK = 3.2mA,
RESET asserted 0.4
Open-Drain RESET Output-
Leakage Current ILKG RESET not asserted, VRESET = +11V 1.0 µA
WATCHDOG FUNCTION
Watchdog Timeout Period tWD 1.12 1.6 2.08 s
WDI Pulse Width tWDI (Note 6) 50 ns
WDI Input Voltage VIL 0.4 V
VIH 2.4
WDI Input Current IWDI WDI = GND -1 +1 µA
NO-LOAD GROUND CURRENT
vs. TEMPERATURE
MAX5023 toc02
TEMPERATURE (°C)
IGND (µA)
1109565 80-10 5 20 35 50-25
10
20
30
40
50
60
70
80
90
100
0
-40 125
VIN = +6.5V
VIN = +14V
VIN = +65V
8
11
14
17
20
5
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX5023 toc03
TEMPERATURE (°C)
ISHDN (µA)
1109565 80-10 5 20 35 50-25-40 125
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
MAX5023 toc01
V
IN
(V)
VOUT (V)
605545 5015 20 25 30 35 405 10
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
0
0 65
IOUT = 0mA
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
www.maximintegrated.com Maxim Integrated
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(VIN = +14V, CIN = 10μF, COUT = 15μF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specied.)
Typical Operating Characteristics (continued)
4.80
4.85
4.90
4.95
5.00
5.05
5.10
5.15
5.20
5.25
4.75
OUTPUT VOLTAGE
vs. TEMPERATURE
MAX5023 toc04
TEMPERATURE (°C)
VOUT (V)
1109565 80-10 5 20 35 50-25-40 125
IOUT = 1mA
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.25
0
GROUND CURRENT
vs. TEMPERATURE
MAX5023 toc05
TEMPERATURE (°C)
IGND (mA)
1109565 80-10 5 20 35 50-25-40 125
ILOAD = 50mA
ILOAD = 150mA
ILOAD = 100mA
VOUT (V)
4.6
4.7
4.8
4.9
5.0
5.1
5.2
5.3
5.4
5.5
4.5
OUTPUT VOLTAGE
vs. LOAD CURRENT AND TEMPERATURE
MAX5023 toc06
TEMPERATURE (°C)
1109565 80-10 5 20 35 50-25-40 125
ILOAD = 50mA
ILOAD = 150mA
ILOAD = 100mA
DROPOUT VOLTAGE
vs. LOAD CURRENT
MAX5023 toc07
I
LOAD
(mA)
DROPOUT VOLTAGE (V)
13011070 905030
0.15
0.30
0.45
0.60
0.75
0.90
1.05
1.20
1.35
1.50
0
10 150
VOUT = 5V
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX5023 toc08
FREQUENCY (kHz)
PSRR (dB)
100101
-70
-60
-50
-40
-30
-20
-10
0
-80
0.1 1000
COUT = 15µF
IOUT = 10mA
LOAD-TRANSIENT RESPONSE
MAX5023 toc09
200µs/div
VOUT
100mV/div
IOUT
100mA/div
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Maxim Integrated
5
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(VIN = +14V, CIN = 10μF, COUT = 15μF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specied.)
Typical Operating Characteristics (continued)
STARTUP RESPONSE
MAX5023 toc11
200µs/div
VOUT
1V/div
5V
65V
0V
0V
VIN
50V/div
VEN = VIN
IOUT = 1mA
ENABLE STARTUP RESPONSE
(VIN = +14V)
MAX5023 toc12
100µs/div
VEN
1V/div
VOUT
2V/div
IOUT = 0mA
ENABLE STARTUP RESPONSE (V
IN
= +14V)
MAX5023 toc13
100µs/div
VEN
1V/div
VOUT
2V/div
IOUT = 150mA
ENABLE STARTUP RESPONSE (V
IN
= +65V)
MAX5023 toc14
100µs/div
VEN
1V/div
VOUT
2V/div
IOUT = 0mA
ENABLE STARTUP RESPONSE (V
IN
= +65V)
MAX5023 toc15
100µs/div
VEN
1V/div
VOUT
2V/div
IOUT = 150mA
INPUT VOLTAGE STEP RESPONSE
MAX5023 toc10
200µs/div
VOUT
1V/div
5V
65V
6.5V
VIN
20V/div
VEN = VIN
IOUT = 1mA
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Maxim Integrated
6
www.maximintegrated.com
(VIN = +14V, CIN = 10μF, COUT = 15μF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specied.)
Typical Operating Characteristics (continued)
SHUTDOWN RESPONSE
MAX5023 toc16
40ms/div
VEN
1V/div
VOUT
2V/div
IOUT = 1mA
ENABLE AND HOLD TIMING
MAX5023 toc17
200ms/div
VEN
5V/div
VOUT
5V/div
VHOLD
5V/div
0
10
5
20
15
25
30
47 5453 56 575548 5251 58 60 6159 80
GROUND-CURRENT DISTRIBUTION
(TA = +40°C)
MAX5023toc18
IGND (µA)
NUMBER OF UNITS
0
10
5
20
15
25
30
45 5958 61 626053 5756 63 65 8964
GROUND-CURRENT DISTRIBUTION
(TA = +125°C)
MAX5023toc19
IGND (µA)
NUMBER OF UNITS
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Maxim Integrated
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www.maximintegrated.com
PIN NAME FUNCTION
MAX5023 MAX5024
1 1 IN Regulator Input. Supply voltage ranges from +6.5V to +65V. Bypass with a 10µF capacitor to
GND.
2 2 EN
Enable Input. Force EN high to turn on the regulator. Pull EN low and force HOLD high (or
open circuit) to place the device in shutdown mode. Internally connected to ground through a
5MΩ resistor.
3 3 GND Ground. GND also functions as a heatsink. Solder to large pads or the circuit-board ground
plane to maximize thermal dissipation.
4 4 RESET
Active-Low Open-Drain Reset Output. RESET remains low while VOUT is below the reset
threshold or when WDI is not pulsed within 1.6s. RESET remains low for the duration of the
reset timeout period after the reset conditions are terminated.
5 5 HOLD
Regulator Hold Input. When HOLD is forced low, the regulator stores the on state of the
output allowing the regulator to function even if EN is pulled low. To shutdown the regulator,
release HOLD after EN is pulled low. If HOLD is unused, either oat HOLD or connect to OUT.
Internally connected to OUT through a 4µA pullup current source (see Table 1, Truth Table).
6 6 N.C. No Connection. Not internally connected.
7WDI Watchdog Timer Input (MAX5023 only). The watchdog timer asserts a reset if WDI does not
transition within the 1.6s watchdog timeout period. WDI cannot be disabled.
8 8 OUT Regulator Output. Fixed (+3.3V or +5V) or adjustable (+2.5V to +11V). Bypass with a 15µF
capacitor (min).
7 SET
Feedback Input for Setting the Output Voltage. Connect to GND to set the output voltage
to the preset xed value (+3.3V or +5V). Connect to an external resistor-divider network for
adjustable output operation (MAX5024 only).
EP Exposed Pad. Connect pad to GND.
N.C.
HOLDRESET
1
2
8
7
OUT
WDIEN
GND
IN
SO-EP
TOP VIEW
3
4
6
5
MAX5023
N.C.
HOLDRESET
1
2
8
7
OUT
SETEN
GND
IN
SO-EP
3
4
6
5
MAX5024
Pin Congurations
Pin Description
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Maxim Integrated
8
www.maximintegrated.com
Detailed Description
The MAX5023/MAX5024 high-voltage linear regulators
include an integrated μP reset circuit and watchdog timer/
adjustable output voltage. The devices guarantee 150mA
load drive and are available with preset output voltages of
+3.3V or +5V. The MAX5023 features a watchdog timer
(WDI) with a 1.6s timeout period. The MAX5024 offers
an adjustable output voltage using an external resistive-
divider network between SET and OUT. The internal reset
circuit monitors the regulator output voltage and asserts a
reset output when the regulator output falls below the μP
supply tolerance. Other features include reverse-voltage
protection to -60V, enable (EN) and hold (HOLD) regula-
tor control inputs, 16μA (max) shutdown current, short-
circuit protection, and thermal shutdown.
Regulator
The regulator accepts an input voltage range from +6.5V
to +65V. The MAX5023/MAX5024 offer fixed output volt-
ages of +3.3V and +5V. The MAX5024 also features an
adjustable output voltage that is implemented with an
external resistive-divider network connected between
OUT, SET, and GND (Figure 1). The MAX5024 auto-
matically determines the feedback path depending on the
voltage at SET. Featured characteristics include reverse-
voltage protection to -60V and enable and hold regulator
control inputs. The Typical Operating Circuit shows a self-
holding configuration for the MAX5023.
Figure 1. Functional Diagram
REVERSE BATTERY PROTECTION
CONTROL
LOGIC BANDGAP
REFERENCE
200ms
TIMEOUT
PERIOD
MUX
OUT
WATCHDOG
TIMER AND
LOGIC
RESET
THERMAL
SENSOR
CURRENT
SENSOR AND
REGULATOR
EN
HOLD
IN +6.5V to +65V
OUT
TO INTERNAL SHUTDOWN
CIRCUITRY
WDI*
*MAX5023 ONLY.
SET
(MAX5024 ONLY)
+2.5V to +11V
GND
R1
R2
4µA
AMP
COMP
Functional Diagram
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
www.maximintegrated.com Maxim Integrated
9
Reset Output
The reset supervisor circuit is fully integrated in the
MAX5023/MAX5024 and uses the same reference volt-
age as the regulator. RESET asserts during power-up/
down and brownout conditions. RESET goes low if VOUT
drops below the preset output voltage threshold, and
remains low for 200ms (reset timeout period, tRP) after
VOUT rises above the reset voltage threshold. For the
MAX5023 only, RESET also asserts when WDI does not
transition for 1.6s (watchdog timeout period, tWD). Two
supply tolerance reset thresholds, -7.5% and -12.5%, are
available for each device type.
Watchdog Timer (MAX5023 only)
A watchdog timer asserts RESET if the watchdog input
(WDI) is not toggled for 1.6s (watchdog timeout period,
tWD). RESET remains low for 200ms (reset timeout
period, tRP). If the watchdog is not updated for lengthy
periods of time, the reset output appears as a pulse
train, asserted for 200ms, deasserted for 1.6s, until WDI
is toggled again. Once RESET asserts, it stays low for
the entire reset timeout period ignoring any WDI transi-
tion during the reset timeout period. Figure 2 shows the
Watchdog Operation Timing Diagram. To prevent the
watchdog from asserting RESET, toggle WDI with a
valid rising or falling edge prior to tWD (min) = 1.12s. The
watchdog counter clears when WDI toggles prior to tWD
or when RESET asserts. The watchdog resumes counting
after RESET deasserts.
Enable and Hold Inputs
The MAX5023/MAX5024 support two logic inputs, EN
(active high) and HOLD (active low), making these devic-
es “automotive friendly.” For example, the ignition drives
EN high, the regulator turns on and remains on even if EN
goes low, as long as HOLD is forced low and stays low
after initial regulator power-up. This feature makes it pos-
sible to implement a self-holding circuit without external
components. Release HOLD (an internal current source
connects HOLD to OUT) to turn the regulator off.
Force EN low and HOLD high to place the MAX5023/
MAX5024 into shutdown mode. Shutdown mode draws
less than 16μA of supply current. Table 1 shows the state
of the regulator output with respect to the voltage level at
Figure 2. Watchdog Operation Timing Diagram
V
OUT
WHEN WATCHDOG IS HELD
HIGH AND EN = HIGH
V
OUT
WHEN WATCHDOG IS HELD
LOW AND EN = HIGH
BATT
BATT
BATT
BATT
POR NORMAL OPERATION WDI HELD HIGH
POR NORMAL OPERATION WDI HELD LOW
EN
WDI
RESET
V
OUT
OV
OV
OV
OV
OV
OV
V
IN
EN
WDI
RESET
V
OUT
V
IN
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
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EN and HOLD. Figure 3 shows the timing diagram for the
enable and hold functions. Connecting HOLD to OUT or
floating HOLD allows the EN input to act as a standard
ON/OFF switch for the regulator output.
Thermal Protection
When the junction temperature exceeds TJ = +150°C, an
internal thermal sensor signals the shutdown logic that
turns off the pass transistor and allows the IC to cool.
The thermal sensor turns the pass transistor on again
after the IC’s junction temperature cools by 20°C, result-
ing in a cycled output during continuous thermal-overload
conditions. Thermal protection protects the MAX5023/
MAX5024 in the event of fault conditions. For continuous
operation, do not exceed the absolute maximum junction
temperature rating of TJ = +150°C.
Applications Information
Output-Voltage Selection (MAX5024 only)
The MAX5024 features Dual Mode™ operation; it oper-
ates in either a preset voltage mode or an adjustable
mode. In preset voltage mode, internal trimmed feedback
resistors set the MAX5024’s internal linear regulator to
+3.3V or +5V (see the Selector Guide).
Figure 3. Enable and Hold Behavior
Dual Mode is a trademark of Maxim Integrated Products, Inc.
VRESET
VOUT
VHOLD
0.2V
200ms
VTH
>10µs>10µs
1)
2)
3)
4) 6)
7)
8)
9)
5)
VOUT (NOM)
VHOLD, HOLD
VHOLD, REL
VEN, OFF
VEN, ON
1) ENABLE ACTIVE
2) HOLD INACTIVE, PULLED UP BY VOUT
3) POWER-ON RESET
4) HOLD ACTIVE, CLAMPED TO GND BY EXTERNAL µP
5) ENABLE INACTIVE, CLAMPED BY INT, PULLDOWN RESISTOR
6) PULSE WIDTH SMALLER THAN 10µs
7) HOLD INACTIVE, RELEASED BY µP
8) REGULATOR OUTPUT SHUTDOWN
9) OUTPUT-LOW RESET
VEN
VIN
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
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11
Select preset voltage mode by connecting SET to ground.
In adjustable mode, select an output between +2.5V and
+11V using two external resistors connected as a voltage-
divider to SET (Figure 4). Set the output voltage using the
following equation:
VOUT = VSET (1 + R1/R2)
where VSET = 1.248V and R2 ≈ 100kΩ.
Available Output-Current Calculation
The MAX5023/MAX5024 high-voltage regulator provides
up to 150mA of output current. The input voltage extends
to +65V. Package power dissipation limits the amount of
output current available for a given input/output voltage
and ambient temperature. Figure 5 depicts the maximum
power dissipation curve for these devices. The graph
assumes that the exposed metal pad of the MAX5023/
MAX5024 package is soldered to 1in2 of PCB copper.
Use Figure 5 to determine the allowable package
dissipation for a given ambient temperature. Alternately,
use the following formula to calculate the allowable
package dissipation:
( )
A
D
AA
1.538W for T 70 C
P1.538 - 0.01923 T - 70 C for 70 C T 125 C
≤+ °


=

° + ° < ≤+ °


After determining the allowable package dissipation,
calculate the maximum output current using the following
formula:
( )
D
OUT MAX IN OUT
P
I 150mA
V -V
≅≤
The above equations do not include the negligible power
dissipation from self-heating due to the IC ground current.
Table 1. Truth Table for Regulator Output
State
Figure 4. Setting the MAX5024 Adjustable Output Voltage
X = Don’t care.
Figure 5. Maximum Power Dissipation vs. Temperature
ORDER EN HOLD OUT Comments
1Low XOff
Initial state. EN has 5MΩ
internal resistor to ground.
HOLD has internal current
source to OUT.
2 High X On Regulator output is active
when EN is pulled high.
3 High Low On
Hold is asserted forcing the
regulator output on even if
EN goes low.
4 X Low On
Self-holding state. Regulator
output stays on regardless of
the state of EN.
5Low High Off
Regulator output is shutdown
by releasing HOLD while EN
remains low.
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
TA (°C)
PD (W)
DERATE
19.23mW/°C
1.538W
IN
EN
GND
HOLD
VOUT = VSET (1 + R1 / R2)
VSET = 1.248V
R2 = 1k TO 500k
SET
OUT
RESET
TO µP
15µF
R1
+6.5V TO +65V +2.5V TO +11V
ON
OFF
R2
MAX5024
10µF
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
www.maximintegrated.com Maxim Integrated
12
Example 1:
TA = +95°C
VIN = +14V
VOUT = +5V
Find the maximum allowable output current. First cal-
culate package dissipation at the given temperature as
follows:
( ) ( )
D
P 1.538W - 0.01923W/ C 95 C-70 C
1.057 W
= ° °°
=
Then determine the maximum output current:
( )
( )
( ) ( )
OUT MAX
1.057W
I 117.4mA
14 V - 5V
= =
Example 2:
TA = +125°C
VIN = +14V
VOUT = +3.3V
Calculate package dissipation at the given temperature
as follows:
( ) ( )
D
P 1.538W- 0.01923W/ C 125 C-70 C
480.4mW
= ° °°
=
And establish the maximum current:
( )
( )
( ) ( )
OUT MAX
480.4mW
I 44.89mA
14 V - 3.3V
= =
Example 3:
TA = +50°C
VIN = +14V
VOUT = +5V
Calculate package dissipation at the given temperature
as follows:
PD = 1.538W
And find the maximum output current:
( )
( )
( ) ( )
( )
OUT MAX OUT MAX
1.538 W
I 170.9mA I 150mA
14 V - 5V
==⇒=
In Example 3, the maximum output current is calculated
as 170.9mA, however, the maximum output current can-
not exceed 150mA. Use Figure 6 to quickly determine
allowable maximum output current for selected ambient
temperatures.
Capacitor Selection and Regulator Stability
For stable operation over the full temperature range
and with load currents up to 150mA, use a 15μF (min)
output capacitor with an ESR < 0.5Ω. To reduce noise
and improve load-transient response, stability, and power-
supply rejection, use larger output capacitor values such
as 22μF.
Some ceramic dielectrics exhibit large capacitance and
ESR variation with temperature. For dielectric capaci-
tors such as Z5U and Y5V, use 22μF or more to ensure
stability at temperatures below -10°C. With X7R or X5R
dielectrics, 15μF should be sufficient at all operating tem-
peratures. For high-ESR tantalum capacitors use 22μF
or more to maintain stability. To improve power-supply
rejection and transient response use a minimum 10μF
capacitor between IN and GND.
Figure 6. Maximum Output Current vs. Input Voltage
50 10 15 20 25 30 35 40 45 60 65 70
50 55
0.02
0
0.04
0.06
0.08
0.10
0.12
0.14
0.16
VIN (V)
IOUT(MAX) (A)
VOUT = +5V
DEVICE EXPOSED
PAD SOLDERED TO
1IN2 COPPER ISLAND
TA = +125°C
TA = +85°C
TA = +70°C
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
www.maximintegrated.com Maxim Integrated
13
Note: These parts offer a choice of reset thresholds, reset
threshold tolerances, and regulator output voltages. From the
Selector Guide, insert the desired suffix letter into the blank to
complete the part number.
/V denotes an automotive qualified part.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
**Future productcontact factory for availability.
Chip Information
PROCESS: BiCMOS
Selector Guide
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
Ordering Information
PART
PRESET
VOUT
RESET THRESHOLD
(VTH)
VOUT RESET
TOLERANCE WATCHDOG
TIMER
ADJUSTABLE
REGULATOR
OUTPUT
/V
5V 3.3V 4.63V 4.38V 3.05V 2.89V VOUT
- 7.5%
VOUT
- 12.5%
MAX5023Lüü üü
MAX5023M ü ü ü ü
MAX5023T ü üüü
MAX5023S ü üü ü
MAX5024L üü ü ü
MAX5024M ü ü üü
MAX5024T ü üü ü
MAX5024S ü üüü ü
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
8L SOIC S8E+14 21-0111 90-0151
PART TEMP RANGE PIN-PACKAGE
MAX5023_ ASA -40°C to +125°C 8 SO-EP*
MAX5023_ ASA/V+** -40°C to +125°C 8 SO-EP*
MAX5024_ ASA -40°C to +125°C 8 SO-EP*
MAX5024_ ASA/V+ -40°C to +125°C 8 SO-EP*
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
www.maximintegrated.com Maxim Integrated
14
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
3 5/14 No /V OPNs; removed automotive reference from Applications section 1
4 3/15
Added /V OPNs to Ordering Information and updated Selector Guide;
added Automotive to Applications section; renumbered notes in Electrical
Characteristics section; moved Ordering Information, Pin Congurations, and
Typical Operating Circuit
1–4, 8, 13
5 5/15 Changed WDI Pulse Width in Electrical Characteristics table from 50ns (min)
to 50ns (typ); updated package code in Package Information section 4, 14
6 5/15 Updated junction-to-ambient thermal resistance in Package Thermal
Characteristics section 2
78/15 Changed MAX5023_ASA/V+ to future product in Ordering Information 14
8 3/16 Updated package type in Package Information section 14
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
© 2016 Maxim Integrated Products, Inc.
15
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