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 8; 3/16
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
