MAX5023 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer
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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 ●● 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 IGNITION SWITCH

65V, Low-Quiescent-Current, High-Voltage Linear Regulators with μP Reset and Watchdog Timer 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 (VIN = +14V, IOUT = 1mA, CIN = 10μF, COUT = 15μF, VEN = +2.4V, HOLD = open, 10kΩ...

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 Enable Voltage Enable Input Current CONDITIONS EN = high, regulator on HOLD Voltage HOLD Pullup Current SET Input Leakage Current Load Regulation Power-Supply Rejection Ratio Short-Circuit Current Thermal-Shutdown Temperature Thermal-Shutdown Hysteresis...

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 VOUT ≥ +1.0V, ISINK = 50µA, RESET asserted VOUT ≥ +2.85V, ISINK = 1.2mA, RESET asserted Open-Drain RESET OutputLeakage Current RESET not asserted, VRESET = +11V VOUT ≥ +4.25V, ISINK = 3.2mA, RESET asserted Open-Drain RESET Output Voltage (Note 5) WATCHDOG...

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.) OUTPUT VOLTAGE vs. LOAD CURRENT AND TEMPERATURE GROUND CURRENT vs. TEMPERATURE OUTPUT VOLTAGE vs. TEMPERATURE DROPOUT VOLTAGE vs. LOAD CURRENT POWER-SUPPLY REJECTION RATIO vs. FREQUENCY LOAD-TRANSIENT RESPONSE

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 ENABLE STARTUP RESPONSE (VIN = +14V) ENABLE STARTUP RESPONSE (VIN = +14V) ENABLE STARTUP RESPONSE (VIN = +65V) ENABLE STARTUP RESPONSE (VIN = +65V)

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

65V, Low-Quiescent-Current, High-Voltage Linear Regulators with μP Reset and Watchdog Timer Regulator Input. Supply voltage ranges from +6.5V to +65V. Bypass with a 10µF capacitor to GND. 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. Ground. GND also functions as a heatsink. Solder to large pads or the circuit-board ground plane to maximize thermal dissipation. Active-Low Open-Drain Reset Output. RESET remains low while VOUT is below the...