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 www.maximintegrated.com 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 www.maximintegrated.com 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) www.maximintegrated.com 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) www.maximintegrated.com 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 www.maximintegrated.com 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) www.maximintegrated.com 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 www.maximintegrated.com 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 www.maximintegrated.com 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 www.maximintegrated.com 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