MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with μP Reset and Watchdog Timer

MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with μP Reset and Watchdog Timer
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
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 regulator, 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
19-2619; Rev 7; 8/15
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 SelfHolding Circuit
●● SET Input for Adjustable Output Voltage (MAX5024)
Selector Guide and Ordering Information appear at end of
data sheet.
Typical Operating Circuit
+6.5V TO +65V
OFF
ON
VCC
OUT
IN
10µF
15µF
µP
MAX5023
IGNITION
SWITCH
MAX5023/MAX5024
10kΩ
RESET
EN
WDI
RESET
I/O
I/O
HOLD
GND
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Absolute Maximum Ratings
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
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.
Package Thermal Characteristics (Note 1)
SO-EP
Junction-to-Ambient Thermal Resistance (θJA)............41°C/W
Junction-to-Case Thermal Resistance (θJC)..................2°C/W
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.
Electrical Characteristics
(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)
PARAMETER
Input Voltage Range
Reverse Input Current
Supply Current
Shutdown Supply Current
SYMBOL
CONDITIONS
MIN
VIN
VIN must be at least 1.5V greater than VOUT
6.5
IREVERSE
IQ
VIN = -60V
Measured at GND
IOUT = 0mA
IOUT = 150mA
TYP
MAX
UNITS
65
V
0.1
10
µA
58
140
2000
ISHDN
VEN ≤ +0.4V
6
16
IOUT
VOUT = +5V
150
SET = GND, IOUT = 1mA to 150mA,
5V version
4.8
5
5.2
SET = GND, IOUT = 1mA to 150mA,
3.3V version
3.168
3.3
3.432
ILOAD = 150mA, VOUT = +5V (Note 3)
0.9
1.5
Rising edge of VIN to VOUT, RL = 500Ω,
SET = GND
400
µA
µA
REGULATOR
Guaranteed Output Current
Output Voltage
VOUT
Dropout Voltage
ΔVDO
IOUT = 5mA, adjustable version (MAX5024)
Startup Response Time
Line Regulation
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ΔVOUT/
ΔVIN
+8V ≤ VIN ≤ +65V
+5V version
+3.3V version
mA
2.5
V
11
V
µs
-1
+1
-0.5
0.5
mV/V
Maxim Integrated │ 2
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Electrical Characteristics (continued)
(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)
PARAMETER
SYMBOL
Enable Voltage
VEN
Enable Input Current
IEN
CONDITIONS
EN = high, regulator on
VEN = +14V
4
VIL
Regulator on, EN transition from high to low
EN = low, regulator shuts off
HOLD Pullup Current
IHOLD
Internally connected to OUT
SET Reference Voltage
VSET
IOUT = 10mA
SET Input Leakage Current
ISET
Short-Circuit Current
Thermal-Shutdown
Temperature
Thermal-Shutdown Hysteresis
0.4
0.5
VIH
Power-Supply Rejection Ratio
MAX
2.4
VEN = +2.4V
HOLD Release Voltage
ΔVOUT/
ΔIOUT
TYP
EN = low, regulator off
HOLD Voltage
Load Regulation
MIN
V
µA
0.4
VOUT - 0.4V
V
V
4
1.223
UNITS
µA
1.248
1.273
V
0.5
100
nA
IOUT = 1mA to 150mA
1
mV/mA
IOUT = 10mA, f = 100Hz, 500mVP-P,
VOUT = +5V
54
dB
300
mA
TJ(SHDN)
150
°C
ΔTJ(SHDN)
20
°C
PSRR
ISC
VIN = +8V
175
RESET CIRCUIT
Reset Threshold
VTH
Reset Timeout Period
tRP
VOUT to Reset Delay
tRD
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MAX502_L, SET = GND
4.50
4.625
4.75
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
140
VOUT falling
200
5
260
V
ms
µs
Maxim Integrated │ 3
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Electrical Characteristics (continued)
(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)
PARAMETER
SYMBOL
Open-Drain RESET Output
Voltage (Note 5)
CONDITIONS
VOL
Open-Drain RESET OutputLeakage Current
ILKG
MIN
TYP
MAX
UNITS
VOUT ≥ +1.0V, ISINK = 50µA,
RESET asserted
0.3
VOUT ≥ +2.85V, ISINK = 1.2mA,
RESET asserted
0.3
VOUT ≥ +4.25V, ISINK = 3.2mA,
RESET asserted
0.4
RESET not asserted, VRESET = +11V
1.0
µA
2.08
s
V
WATCHDOG FUNCTION
Watchdog Timeout Period
tWD
WDI Pulse Width
tWDI
(Note 6)
ns
0.4
VIH
WDI Input Current
1.6
50
VIL
WDI Input Voltage
Note
Note
Note
Note
Note
1.12
2.4
IWDI
WDI = GND
-1
+1
V
µA
2: Limits at -40°C are guaranteed by characterization and not production tested.
3: Dropout voltage is defined as VIN - VOUT when VOUT is 100mV below the value of VOUT for VIN = VOUT + 3V.
4:VOUT = VSET (1 + R1/R2) = 1.248V (1 + R1/R2).
5: RESET is guaranteed to be in the correct logic state for VOUT > +1V.
6: Guaranteed by design, not production tested.
Typical Operating Characteristics
(VIN = +14V, CIN = 10μF, COUT = 15μF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specified.)
4.5
90
80
17
3.0
2.5
2.0
60
VIN = +14V
50
40
VIN = +6.5V
ISHDN (µA)
3.5
14
11
30
1.5
1.0
20
0.5
10
0
VIN = +65V
70
IGND (µA)
VOUT (V)
4.0
20
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX5023 toc03
5.0
NO-LOAD GROUND CURRENT
vs. TEMPERATURE
MAX5023 toc02
100
MAX5023 toc01
5.5
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
IOUT = 0mA
0 5 10 15 20 25 30 35 40 45 50 55 60 65
VIN (V)
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0
8
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
5
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Maxim Integrated │ 4
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Typical Operating Characteristics (continued)
(VIN = +14V, CIN = 10μF, COUT = 15μF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specified.)
5.20
5.15
2.00
1.75
1.50
5.00
4.95
4.85
0.50
4.80
0.25
IOUT = 1mA
-40 -25 -10 5 20 35 50 65 80 95 110 125
4.8
ILOAD = 100mA
ILOAD = 150mA
4.7
4.6
ILOAD = 50mA
-40 -25 -10 5 20 35 50 65 80 95 110 125
4.5
-40 -25 -10 5 20 35 50 65 80 95 110 125
DROPOUT VOLTAGE
vs. LOAD CURRENT
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
LOAD-TRANSIENT RESPONSE
0
-10
MAX5023 toc09
-20
1.05
PSRR (dB)
0.90
0.75
0.60
0.45
VOUT
100mV/div
-30
-40
-50
IOUT
100mA/div
-60
0.30
0.15
50
70
90
ILOAD (mA)
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110
130
COUT = 15µF
IOUT = 10mA
-70
VOUT = 5V
30
4.9
TEMPERATURE (°C)
1.20
10
5.0
TEMPERATURE (°C)
1.35
0
ILOAD = 50mA
TEMPERATURE (°C)
MAX5023 toc07
1.50
DROPOUT VOLTAGE (V)
0
ILOAD = 100mA
5.1
MAX5023 toc08
4.75
5.2
1.00
0.75
4.90
5.3
ILOAD = 150mA
1.25
OUTPUT VOLTAGE
vs. LOAD CURRENT AND TEMPERATURE
5.4
VOUT (V)
5.05
IGND (mA)
VOUT (V)
5.10
5.5
MAX5023 toc05
2.25
MAX5023 toc04
5.25
GROUND CURRENT
vs. TEMPERATURE
MAX5023 toc06
OUTPUT VOLTAGE
vs. TEMPERATURE
150
-80
0.1
1
10
100
1000
200µs/div
FREQUENCY (kHz)
Maxim Integrated │ 5
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Typical Operating Characteristics (continued)
(VIN = +14V, CIN = 10μF, COUT = 15μF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specified.)
INPUT VOLTAGE STEP RESPONSE
STARTUP RESPONSE
MAX5023 toc10
5V
VOUT
1V/div
5V
ENABLE STARTUP RESPONSE
(VIN = +14V)
MAX5023 toc11
VEN = VIN
IOUT = 1mA
MAX5023 toc12
VEN
1V/div
VOUT
1V/div
65V
VIN
20V/div
VEN = VIN
IOUT = 1mA
6.5V
200µs/div
0V
65V
VIN
50V/div
0V
ENABLE STARTUP RESPONSE (VIN = +14V)
VOUT
2V/div
IOUT = 0mA
200µs/div
100µs/div
ENABLE STARTUP RESPONSE (VIN = +65V)
MAX5023 toc13
ENABLE STARTUP RESPONSE (VIN = +65V)
MAX5023 toc14
MAX5023 toc15
VEN
1V/div
VEN
1V/div
VEN
1V/div
VOUT
2V/div
VOUT
2V/div
VOUT
2V/div
IOUT = 0mA
IOUT = 150mA
100µs/div
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100µs/div
IOUT = 150mA
100µs/div
Maxim Integrated │ 6
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Typical Operating Characteristics (continued)
(VIN = +14V, CIN = 10μF, COUT = 15μF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specified.)
ENABLE AND HOLD TIMING
SHUTDOWN RESPONSE
MAX5023 toc17
MAX5023 toc16
VEN
1V/div
VEN
5V/div
VHOLD
5V/div
VOUT
2V/div
VOUT
5V/div
IOUT = 1mA
40ms/div
200ms/div
GROUND-CURRENT DISTRIBUTION
(TA = +40°C)
GROUND-CURRENT DISTRIBUTION
(TA = +125°C)
20
15
10
5
MAX5023toc19
25
NUMBER OF UNITS
NUMBER OF UNITS
25
0
30
MAX5023toc18
30
20
15
10
5
47 48 51 52 53 54 55 56 57 58 59 60 61 80
IGND (µA)
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0
45 53 56 57 58 59 60 61 62 63 64 65 89
IGND (µA)
Maxim Integrated │ 7
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Pin Configurations
TOP VIEW
IN
1
EN
2
GND
3
8
MAX5023
RESET 4
OUT
IN
1
7
WDI
EN
2
6
N.C.
GND
3
5
HOLD
8
MAX5024
RESET 4
SO-EP
OUT
7
SET
6
N.C.
5
HOLD
SO-EP
Pin Description
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.
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 float HOLD or connect to OUT.
Internally connected to OUT through a 4µA pullup current source (see Table 1, Truth Table).
5
5
HOLD
6
6
N.C.
No Connection. Not internally connected.
7
—
WDI
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 fixed value (+3.3V or +5V). Connect to an external resistor-divider network for
adjustable output operation (MAX5024 only).
—
—
EP
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Exposed Pad. Connect pad to GND.
Maxim Integrated │ 8
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Detailed Description
tor control inputs, 16μA (max) shutdown current, shortcircuit protection, and thermal shutdown.
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 resistivedivider 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-
Regulator
The regulator accepts an input voltage range from +6.5V
to +65V. The MAX5023/MAX5024 offer fixed output voltages 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 automatically determines the feedback path depending on the
voltage at SET. Featured characteristics include reversevoltage protection to -60V and enable and hold regulator
control inputs. The Typical Operating Circuit shows a selfholding configuration for the MAX5023.
Functional Diagram
IN
+6.5V to +65V
REVERSE BATTERY PROTECTION
OUT
4µA
HOLD
EN
CONTROL
LOGIC
BANDGAP
REFERENCE
AMP
+2.5V to +11V
OUT
THERMAL
SENSOR
MUX
R1
COMP
CURRENT
SENSOR AND
REGULATOR
SET
(MAX5024 ONLY)
TO INTERNAL SHUTDOWN
CIRCUITRY
R2
RESET
WDI*
*MAX5023 ONLY.
WATCHDOG
TIMER AND
LOGIC
200ms
TIMEOUT
PERIOD
GND
Figure 1. Functional Diagram
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Maxim Integrated │ 9
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
BATT
VIN
BATT
EN
VOUT WHEN WATCHDOG IS HELD
HIGH AND EN = HIGH
WDI OV
RESET OV
VOUT OV
POR
NORMAL OPERATION
WDI HELD HIGH
NORMAL OPERATION
WDI HELD LOW
BATT
VIN
BATT
EN
VOUT WHEN WATCHDOG IS HELD
LOW AND EN = HIGH
WDI OV
RESET OV
VOUT OV
POR
Figure 2. Watchdog Operation Timing Diagram
Reset Output
The reset supervisor circuit is fully integrated in the
MAX5023/MAX5024 and uses the same reference voltage 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 transition during the reset timeout period. Figure 2 shows the
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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 devices “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 possible 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
Maxim Integrated │ 10
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
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, resulting 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 operates 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).
VIN
VEN
VEN, ON
5)
1)
VEN, OFF
>10µs
VHOLD
VHOLD, REL
2)
4)
VHOLD, HOLD
>10µs
6)
7)
VOUT
VTH
VOUT (NOM)
8)
200ms
VRESET
0.2V
3)
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
9)
6) PULSE WIDTH SMALLER THAN 10µs
7) HOLD INACTIVE, RELEASED BY µP
8) REGULATOR OUTPUT SHUTDOWN
9) OUTPUT-LOW RESET
Figure 3. Enable and Hold Behavior
Dual Mode is a trademark of Maxim Integrated Products, Inc.
www.maximintegrated.com
Maxim Integrated │ 11
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Table 1. Truth Table for Regulator Output
State
ORDER
1
2
EN
Low
High
HOLD
X
X
OUT
Off
+6.5V TO +65V
Comments
10µF
Initial state. EN has 5MΩ
internal resistor to ground.
HOLD has internal current
source to OUT.
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.
5
Low
High
Off
Regulator output is shutdown
by releasing HOLD while EN
remains low.
+2.5V TO +11V
OUT
IN
15µF
MAX5024
HOLD
OFF
ON
R1
EN
SET
TO µP
R2
RESET
GND
VOUT = VSET (1 + R1 / R2)
VSET = 1.248V
R2 = 1kΩ TO 500kΩ
Figure 4. Setting the MAX5024 Adjustable Output Voltage
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 voltagedivider 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:
1.538 W for T A ≤ +70° C

PD = 

°
+
°
<
≤
+
°
1.538
0.01923
T
70
C
for
70
C
T
125
C
(
)
A
A


www.maximintegrated.com
PD (W)
X = Don’t care.
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
1.538W
DERATE
19.23mW/°C
10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
TA (°C)
Figure 5. Maximum Power Dissipation vs. Temperature
After determining the allowable package dissipation,
calculate the maximum output current using the following
formula:
I OUT(MAX) ≅
PD
VIN -VOUT
≤ 150mA
The above equations do not include the negligible power
dissipation from self-heating due to the IC ground current.
Maxim Integrated │ 12
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Example 1:
TA = +95°C
0.16
VIN = +14V
VOUT = +5V
DEVICE EXPOSED
PAD SOLDERED TO
1IN2 COPPER ISLAND
0.14
VOUT = +5V
Find the maximum allowable output current. First calculate package dissipation at the given temperature as
follows:
= 1.057 W
Then determine the maximum output current:
(1.057 W )
I=
=
OUT(MAX)
(14 V)-(5V)
TA = +70°C
0.10
IOUT(MAX) (A)
=
PD 1.538 W - (0.01923W/ ° C) (95 ° C-70 ° C)
0.12
0.08
TA = +85°C
0.06
0.04
117.4mA
0
Example 2:
TA = +125°C
VIN = +14V
TA = +125°C
0.02
0
5
10 15
20 25
30 35 40
VIN (V)
45 50
55 60 65
70
Figure 6. Maximum Output Current vs. Input Voltage
VOUT = +3.3V
Calculate package dissipation at the given temperature
as follows:
=
PD 1.538 W - (0.01923W/ ° C) (125° C-70 ° C)
= 480.4mW
Capacitor Selection and Regulator Stability
And establish the maximum current:
(480.4mW )
=
(14 V)-(3.3V)
=
I OUT(MAX)
In Example 3, the maximum output current is calculated
as 170.9mA, however, the maximum output current cannot exceed 150mA. Use Figure 6 to quickly determine
allowable maximum output current for selected ambient
temperatures.
44.89mA
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:
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 powersupply rejection, use larger output capacitor values such
as 22μF.
Some ceramic dielectrics exhibit large capacitance and
ESR variation with temperature. For dielectric capacitors 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 temperatures. 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.
(1.538 W )
=
I OUT(MAX) =
170.9mA ⇒ I OUT(MAX) =
150mA
(14 V)-(5V)
www.maximintegrated.com
Maxim Integrated │ 13
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Selector Guide
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%
MAX5023L
ü
—
ü
—
—
—
ü
—
ü
—
—
MAX5023M
ü
—
—
ü
—
—
—
ü
ü
—
—
MAX5023T
—
ü
—
—
ü
—
ü
—
ü
—
—
MAX5023S
—
ü
—
—
—
ü
—
ü
ü
—
—
MAX5024L
ü
—
ü
—
—
—
ü
—
—
ü
—
MAX5024M
ü
—
—
ü
—
—
—
ü
—
ü
—
MAX5024T
—
ü
—
—
ü
—
ü
—
—
ü
—
MAX5024S
—
ü
—
—
—
ü
—
ü
—
ü
ü
Ordering Information
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*
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 product—contact factory for availability.
www.maximintegrated.com
Chip Information
PROCESS: BiCMOS
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.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
28 TSSOP
S8E+14
21-0111
90-0151
Maxim Integrated │ 14
MAX5023/MAX5024
65V, Low-Quiescent-Current, High-Voltage Linear
Regulators with μP Reset and Watchdog Timer
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
3
5/14
No /V OPNs; removed automotive reference from Applications section
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 Configurations, 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
7
8/15
Changed MAX5023_ASA/V+ to future product in Ordering Information
14
DESCRIPTION
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
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 specifications 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.
© 2015 Maxim Integrated Products, Inc. │ 15
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