19-2619; Rev 2; 5/05 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer Features 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. ♦ Wide Operating Input Voltage Range +6.5V to +65V 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. ♦ Operate Over -40°C to +125°C Temperature Range Applications Automotive Fire/Smoke Alarms Industrial Telecom/Networking ♦ 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 ♦ 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) Ordering Information PART TEMP RANGE MAX5023_ ASA -40°C to +125°C 8 SO-EP* PIN-PACKAGE MAX5024_ ASA -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. *EP = Exposed Paddle. Selector Guide and Typical Operating Circuit appear at end of data sheet. Home Security Pin Configurations TOP VIEW 8 OUT IN 7 WDI EN 2 3 6 N.C. RESET 4 5 HOLD IN 1 EN 2 1 8 OUT 7 SET 3 6 N.C. RESET 4 5 HOLD MAX5024 MAX5023 GND SO-EP GND SO-EP ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX5023/MAX5024 General Description 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 Thermal Resistance: (θJA) .............................................................................52°C/W (θJC) ...............................................................................2°C/W 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. 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 1) 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 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 2) 0.9 1.5 Rising edge of VIN to VOUT, RL = 500Ω, SET = GND 400 6 16 µA µA REGULATOR Guaranteed Output Current Output Voltage VOUT Dropout Voltage ∆VDO IOUT = 5mA, adjustable version (MAX5024) Startup Response Time Line Regulation ∆VOUT/ ∆VIN Enable Voltage VEN Enable Input Current IEN HOLD Voltage VIL Regulator on, EN transition from high to low HOLD Release Voltage VIH EN = low, regulator shuts off HOLD Pullup Current IHOLD Internally connected to OUT SET Reference Voltage VSET IOUT = 10mA SET Input Leakage Current ISET 2 +8V ≤ VIN ≤ +65V +5V version +3.3V version EN = high, regulator on mA 2.5 11 +1 -0.5 0.5 2.4 EN = low, regulator off 0.4 VEN = +2.4V 0.5 VEN = +14V 4 V µs -1 mV/V V µA 0.4 VOUT 0.4V V V 4 1.223 V µA 1.248 1.273 V 0.5 100 nA _______________________________________________________________________________________ 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer (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 1) PARAMETER SYMBOL ∆VOUT/ ∆IOUT Load Regulation Power-Supply Rejection Ratio Short-Circuit Current Thermal-Shutdown Temperature Thermal-Shutdown Hysteresis CONDITIONS MIN TYP MAX UNITS IOUT = 1mA to 150mA 1 mV/mA IOUT = 10mA, f = 100Hz, 500mVP-P, VOUT = +5V 54 dB 300 mA TJ(SHDN) 150 °C ∆TJ(SHDN) 20 °C PSRR ISC VIN = +8V 175 RESET CIRCUIT Reset Threshold VTH Reset Timeout Period tRP VOUT to Reset Delay tRD Open-Drain RESET Output Voltage (Note 4) Open-Drain RESET OutputLeakage Current VOL ILKG MAX502_L, SET = GND 4.50 4.625 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 3) 0.925 x VOUT MAX5024M/S, SET = Divider (Figure 1) (Note 3) 0.875 x VOUT 140 VOUT falling 200 4.75 260 5 V ms µs 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 WDI Input Voltage WDI Input Current 1.12 (Note 5) 50 VIL ns 0.4 2.4 VIH IWDI 1.6 WDI = GND -1 +1 V µA Note 1: Limits at -40°C are guaranteed by characterization and not production tested. Note 2: Dropout voltage is defined as VIN - VOUT when VOUT is 100mV below the value of VOUT for VIN = VOUT + 3V. Note 3: VOUT = VSET (1 + R1 / R2) = 1.248V (1 + R1 / R2). Note 4: RESET is guaranteed to be in the correct logic state for VOUT > +1V. Note 5: Guaranteed by design, not production tested. _______________________________________________________________________________________ 3 MAX5023/MAX5024 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VIN = +14V, CIN = 10µF, COUT = 15µF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specified.) NO-LOAD GROUND CURRENT vs. TEMPERATURE 5.0 4.5 90 4.0 2.5 60 40 1.5 1.0 20 0.5 10 IOUT = 0mA VIN = +14V 50 30 0 ISHDN (µA) IGND (µA) VIN = +6.5V 14 11 8 5 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 VIN (V) TEMPERATURE (°C) TEMPERATURE (°C) OUTPUT VOLTAGE vs. TEMPERATURE GROUND CURRENT vs. TEMPERATURE OUTPUT VOLTAGE vs. LOAD CURRENT AND TEMPERATURE 5.15 2.00 1.75 5.10 1.50 5.00 4.95 1.00 0.50 4.80 0.25 IOUT = 1mA 4.75 5.2 1.25 4.85 5.3 ILOAD = 150mA ILOAD = 100mA ILOAD = 50mA 5.1 5.0 4.9 0.75 4.90 5.4 VOUT (V) IGND (mA) 5.05 5.5 MAX5023 toc06 5.20 MAX5023 toc05 2.25 MAX5023 toc04 5.25 ILOAD = 100mA 4.8 ILOAD = 150mA 4.7 4.6 ILOAD = 50mA 0 4.5 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) DROPOUT VOLTAGE vs. LOAD CURRENT POWER-SUPPLY REJECTION RATIO vs. FREQUENCY LOAD-TRANSIENT RESPONSE 1.35 1.20 MAX5023 toc09 0 MAX5023 toc07 1.50 MAX5023 toc08 VOUT (V) 3.0 2.0 -10 -20 VOUT 100mV/div PSRR (dB) 1.05 0.90 0.75 0.60 -30 -40 -50 0.45 IOUT 100mA/div -60 0.30 0.15 COUT = 15µF IOUT = 10mA -70 VOUT = 5V -80 0 10 30 50 70 90 ILOAD (mA) 4 17 70 3.5 VOUT (V) VIN = +65V 80 20 MAX5023 toc02 100 MAX5023 toc01 5.5 SHUTDOWN SUPPLY CURRENT vs. TEMPERATURE MAX5023 toc03 OUTPUT VOLTAGE vs. INPUT VOLTAGE DROPOUT VOLTAGE (V) MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer 110 130 150 0.1 1 10 100 1000 200µs/div FREQUENCY (kHz) _______________________________________________________________________________________ 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer INPUT VOLTAGE STEP RESPONSE ENABLE STARTUP RESPONSE (VIN = +14V) STARTUP RESPONSE MAX5023 toc10 MAX5023 toc11 5V VOUT 1V/div VEN = VIN IOUT = 1mA 5V MAX5023 toc12 VEN 1V/div VOUT 1V/div 65V VIN 20V/div VEN = VIN IOUT = 1mA 6.5V VOUT 2V/div 0V 65V VIN 50V/div 0V IOUT = 0mA 200µs/div 200µs/div ENABLE STARTUP RESPONSE (VIN = +14V) 100µs/div ENABLE STARTUP RESPONSE (VIN = +65V) ENABLE STARTUP RESPONSE (VIN = +65V) MAX5023 toc13 MAX5023 toc15 MAX5023 toc14 VEN 1V/div VEN 1V/div VEN 1V/div VOUT 2V/div VOUT 2V/div VOUT 2V/div IOUT = 150mA IOUT = 150mA IOUT = 0mA 100µs/div 100µs/div 100µs/div 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 _______________________________________________________________________________________ 5 MAX5023/MAX5024 Typical Operating Characteristics (continued) (VIN = +14V, CIN = 10µF, COUT = 15µF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specified.) Typical Operating Characteristics (continued) (VIN = +14V, CIN = 10µF, COUT = 15µF, VEN = +2.4V, VOUT = +5V, SET = GND, TA = +25°C, unless otherwise specified.) GROUND-CURRENT DISTRIBUTION (TA = +40°C) GROUND-CURRENT DISTRIBUTION (TA = +125°C) 25 NUMBER OF UNITS 25 20 15 10 MAX5023toc19 30 MAX5023toc18 30 NUMBER OF UNITS MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer 5 20 15 10 5 0 0 47 48 51 52 53 54 55 56 57 58 59 60 61 80 45 53 56 57 58 59 60 61 62 63 64 65 89 IGND (µA) IGND (µA) 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). 6 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 EP PAD Exposed Pad. Connect pad to GND. _______________________________________________________________________________________ 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer 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) regulator 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 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 reverse-voltage protection to -60V and enable and hold regulator control inputs. The Typical Operating Circuit shows a self-holding 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 SET CURRENT SENSOR AND REGULATOR (MAX5024 ONLY) R2 TO INTERNAL SHUTDOWN CIRCUITRY RESET WDI* *MAX5023 ONLY. WATCHDOG TIMER AND LOGIC 200ms TIMEOUT PERIOD GND Figure 1. Functional Diagram _______________________________________________________________________________________ 7 MAX5023/MAX5024 Detailed Description 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 powerup/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 transitions during the reset timeout period. 8 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 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 _______________________________________________________________________________________ 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer load 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. Thermal Protection Applications Information 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-over- 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 >10µs VHOLD VHOLD, REL 2) 4) VHOLD, HOLD 6) 7) VOUT VTH VOUT (NOM) 8) 200ms VRESET 3) 9) 0.2V 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 Figure 3. Enable and Hold Behavior Dual Mode is a trademark of Maxim Integrated Products, Inc. _______________________________________________________________________________________ 9 MAX5023/MAX5024 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. Table 1. Truth Table for Regulator Output State +6.5V TO +65V ORDER 1 2 EN Low High HOLD X X OUT Off 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 COMMENTS 15µF MAX5024 HOLD ON OFF 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 X = Don’t care. 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 PC board 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: 1.538W for TA ≤ +70°C PD = 1.538 - 0.01923 ( TA - 70°C) for + 70°C < TA ≤ +125°C 10 PD (W) MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer 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: IOUT(MAX) ≅ PD ≤ 150mA VIN - VOUT The above equations do not include the negligible power dissipation from self-heating due to the IC ground current. ______________________________________________________________________________________ 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer MAX5023/MAX5024 Example 1: TA = +95°C PD = 1.538W - (0.01923W/ °C) (95°C - 70°C) = 1.057W Then determine the maximum output current: IOUT(MAX) = (1.057W) = 117.4mA 14 ( V) - (5V) 0.16 VOUT = +5V DEVICE EXPOSED PAD SOLDERED TO 1IN2 COPPER ISLAND 0.14 0.12 IOUT(MAX) (A) VIN = +14V VOUT = +5V Find the maximum allowable output current. First calculate package dissipation at the given temperature as follows: 0.10 MAX5023 fig04 MAXIMUM OUTPUT CURRENT vs. INPUT VOLTAGE TA = +70°C 0.08 TA = +85°C 0.06 0.04 0.02 TA = +125°C 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 VIN (V) Figure 6. Maximum Output Current vs. Input Voltage Example 2: TA = +125°C VIN = +14V VOUT = +3.3V Calculate package dissipation at the given temperature as follows: PD = 1.538W - (0.01923W/ °C) (125°C - 70°C) = 480.4mW And establish the maximum current: IOUT(MAX) = (480.4mW) = 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: IOUT(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. 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 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. (1.538W) = 170.9mA ⇒ I OUT(MAX) = 150mA (14 V) - (5V) ______________________________________________________________________________________ 11 Selector Guide RESET THRESHOLD (VTH) PRESET VOUT PART 5V 3.3V MAX5023L ✔ MAX5023M ✔ MAX5023T — MAX5023S MAX5024L VOUT RESET TOLERANCE WATCHDOG TIMER ADJUSTABLE REGULATOR OUTPUT — VOUT 7.5% VOUT 12.5% — ✔ — ✔ — — ✔ ✔ — — ✔ — ✔ — — ✔ — ✔ ✔ — — — ✔ — — ✔ — — — ✔ — ✔ — ✔ — ✔ — — ✔ — — ✔ — ✔ — ✔ 4.63V 4.38V 3.05V 2.89V — ✔ — — — — ✔ — ✔ — — ✔ — ✔ — — ✔ — ✔ — MAX5024M ✔ — — ✔ MAX5024T — ✔ — MAX5024S — ✔ — Bold Items indicate standard versions. Samples are generally available on standard versions only. Contact factory for availability of nonstandard versions. Set MAX5024’s adjustable output voltage by connecting a resistive-divider from OUT to SET (see the Output Voltage Selection section). Typical Operating Circuit +6.5V TO +65V VCC OUT IN 10µF 15µF µP MAX5023 10kΩ RESET ON OFF Chip Information TRANSISTOR COUNT: 1382 PROCESS: BiCMOS IGNITION SWITCH MAX5023/MAX5024 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer RESET EN WDI I/O I/O HOLD GND 12 ______________________________________________________________________________________ 65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog Timer 8L, SOIC EXP. PAD.EPS PACKAGE OUTLINE 8L SOIC, .150" EXPOSED PAD 21-0111 B 1 1 Note: For exposed pad dimension, use S8E-14 package dimensions. Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. MAX5023/MAX5024 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.)