19-3875; Rev 1; 8/06 KIT ATION EVALU E L B AVAILA High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions The MAX6791–MAX6796 ultra-low-quiescent-current, single-/dual-output linear regulators are ideal for automotive applications. The devices offer a wide 5V to 72V operating input range, allowing them to withstand automotive load-dump conditions while consuming only 68µA. The MAX6791–MAX6794 are dual-output regulators capable of supplying up to 150mA per output. The MAX6795/MAX6796 offer a single output capable of delivering up to 300mA. These devices offer standard output-voltage options (5V, 3.3V, 2.5V, or 1.8V) and can be adjusted to any voltage from 1.8V to 11V. The MAX6791–MAX6794 also offer a fixed 5V output. All devices feature a push-pull or open-drain, active-low RESET output with a fixed output reset threshold that is 92.5%/87.5% of the regulator output OUT/OUT1. The reset output asserts low when OUT/OUT1 drops below the reset threshold and remains low for the fixed or capacitor-adjustable reset timeout period after OUT/OUT1 exceeds the reset threshold. The MAX6791–MAX6796 provide a watchdog input that monitors a pulse train from the microprocessor (µP) and generates reset pulses if the watchdog input remains high or low for a duration longer than the watchdog timeout period. All devices are available with either a fixed watchdog timeout period of 280ms (min) or a period adjustable with an external capacitor. The MAX6791/MAX6792 feature a windowed watchdog timeout period with selectable window ratio. The watchdog feature can be disabled. The MAX6791–MAX6794 provide dual enable inputs (ENABLE1 and ENABLE2) that control each regulator independently. The single-output MAX6795/MAX6796 feature one enable input (ENABLE). All devices include a hold input (HOLD) that aids the implementation of a self-holding circuit without requiring external components. Once the regulator is enabled, setting HOLD low forces the regulator to remain on even if ENABLE/ENABLE1 is subsequently set low. Releasing HOLD shuts down the regulator. The MAX6791–MAX6796 are available in a small, thermally enhanced TQFN package. The 5mm x 5mm package dissipates up to 2.7W, supporting continuous regulator operation during high ambient temperatures, high battery voltage, and high load-current conditions. The MAX6791–MAX6796 are specified for a -40°C to +125°C operating temperature range. Applications Automotive Features ♦ Low 68µA Quiescent Current ♦ Wide 5V to 72V Supply Voltage Range ♦ Output Current Single Output Up to 300mA Dual Outputs Up to 150mA per Output ♦ Low Dropout Voltage 420mV (typ) at 100mA (Single) 840mV (typ) at 100mA (Dual) ♦ Fixed Output-Voltage Options: 5V, 3.3V, 2.5V, 1.8V, or Adjustable Output (from 1.8V to 11V) ♦ ENABLE and HOLD Functionality ♦ RESET Output: Open Drain or Push-Pull ♦ Internally Fixed (35µs, 3.125ms, 12.5ms, 50ms, or 200ms) or Capacitor-Adjustable Reset Timeout Periods ♦ Internally Fixed or Capacitor-Adjustable Watchdog Timeout Periods ♦ Windowed (Minimum/Maximum) Watchdog Timer Options (MAX6791/MAX6792) ♦ Watchdog Disable Feature ♦ Thermal, Short-Circuit, and Output Overvoltage Protection ♦ Fully Specified from -40°C to +125°C ♦ Small, Thermally Enhanced, 5mm x 5mm TQFN Ordering Information PART TEMP RANGE PINPACKAGE PKG CODE MAX6791TP_D _+ -40°C to +125°C 20 TQFN T2055-4 MAX6792TP_D _+ -40°C to +125°C 20 TQFN T2055-4 MAX6793TP_ D_+ -40°C to +125°C 20 TQFN T2055-4 MAX6794TP_ D_+ -40°C to +125°C 20 TQFN T2055-4 MAX6795TP_ D_+ -40°C to +125°C 20 TQFN T2055-4 MAX6796TP_D _+ -40°C to +125°C 20 TQFN T2055-4 +Denotes lead-free package. For tape-and-reel, add a T after the “+.” Tape-and-reel are offered in 2.5k increments. The first placeholder “_” designates preset output-voltage option and preset reset threshold level; see Table 1. The second placeholder “_ ” designates the reset timeout period; see Table 2. For example, the MAX6791TPSD3+ indicates a 3.3V output voltage with a reset threshold of 87.5% at nominal voltage and a 50ms reset timeout period. Samples are generally held in stock. Nonstandard versions require a 2.5k minimum order quantity. Typical Application Circuit, Pin Configurations, and Selector Guide appear at end of data sheet. ________________________________________________________________ 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 MAX6791–MAX6796 General Description MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions ABSOLUTE MAXIMUM RATINGS (All pins referenced to GND, unless otherwise noted.) IN to GND ...............................................................-0.3V to +80V ENABLE, ENABLE1, ENABLE2, PFI, GATEP to GND ...........................................-0.3V to (IN + 0.3V) GATEP to IN ...........................................................-12V to +0.3V OUT, OUT1, OUT2, PFO, RESET (open-drain versions), CSRT, CSWT .......................................................-0.3V to +12V HOLD, RESET (push-pull versions), WDI, WDS0, WDS1, WD-DIS, SET, SET1......................-0.3V to (OUT/OUT1 + 0.3V) OUT, OUT1, OUT2 Short Circuit to GND....................................................................Continuous Maximum Current (all pins except IN and OUT_)...............50mA Continuous Power Dissipation (TA = +70°C) 20-Pin TQFN (derate 33.3mW/°C above +70°C) .....2666.7mW Operating Temperature Range (TA) ..................-40°C to +125°C Junction Temperature (TJ) .................................................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, CIN = 1µF, COUT = 10µF, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = TJ = +25°C.) (Note 1) PARAMETER Supply Voltage Range SYMBOL CONDITIONS VIN Shutdown Supply Current 2 IIN ISHDN TYP 5 Regulators on (ILOAD = 0mA), VIN = 8V VIN = 8V, ILOAD = 300mA (MAX6795/MAX6796) Supply Current MIN MAX UNITS 72 V 68 85 130 220 VIN = 14V, ILOAD = 100mA (MAX6795/MAX6796) 100 160 VIN = 8V, ILOAD1 = ILOAD2 = 150mA (MAX6791–MAX6794) 130 220 VIN = 14V, ILOAD1 = ILOAD2 = 50mA (MAX6791–MAX6794) 100 160 Regulators on (ILOAD = 0mA), VIN = 42V 74 95 Regulators on (ILOAD = 20mA, total) OUT1/OUT2/OUT = 5V, VIN = 42V 100 170 Regulators off, VIN = 14V 27 45 Regulators on, OUT/OUT1 = OUT2 = 5V _______________________________________________________________________________________ µA µA High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions (VIN = 14V, CIN = 1µF, COUT = 10µF, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = TJ = +25°C.) (Note 1) PARAMETER SYMBOL VOUT/ VOUT1 Output Voltage Output Voltage (MAX6791–MAX6794) VOUT2 SET/SET1 Threshold Voltage VSET Adjustable Output Voltage VOUT Dual-Mode™ SET Threshold SET/SET1 Input Current ∆VDO Dropout Voltage MIN TYP MAX L/M, ILOAD = ILOAD1 = 1mA CONDITIONS 4.858 4.974 5.090 L/M, ILOAD = 150mA (MAX6791–MAX6794), VIN = 8V 4.811 4.945 5.078 L/M, ILOAD = 300mA (MAX6795/MAX6796), VIN = 8V 4.850 5 5.150 T/S, ILOAD = ILOAD1 = 1mA 3.206 3.282 3.360 T/S, ILOAD = 150mA (MAX6791–MAX6794), VIN = 6V 3.175 3.263 3.351 T/S, ILOAD = 300mA (MAX6795/MAX6796), VIN = 6V 3.201 3.3 3.399 Z/Y, ILOAD = ILOAD1 = 1mA 2.429 2.487 2.546 Z/Y, ILOAD = 150mA (MAX6791–MAX6794), VIN = 5.5V 2.405 2.472 2.539 Z/Y, ILOAD = 300mA (MAX6795/MAX6796), VIN = 5.5V 2.425 2.5 2.575 W/V, ILOAD = ILOAD1 = 1mA 1.748 1.791 1.832 W/V, ILOAD = 150mA (MAX6791–MAX6794), VIN = 5V 1.731 1.780 1.828 W/V, ILOAD = 300mA (MAX6795/MAX6796), VIN = 5V 1.746 1.8 1.854 ILOAD2 = 1mA 4.858 4.974 5.090 ILOAD2 = 150mA 4.811 4.945 5.079 ILOAD = ILOAD1 = 1mA, OUT/OUT1 = 5V 1.207 1.2315 1.256 V 11.0 V 1.8 SET/SET1 rising 124 SET/SET1 falling 62 SET/SET1 = 1V, VIN = 11V L/M, ILOAD = 20mA (Note 2) (MAX6795/ L/M, ILOAD = 300mA (Note 2) MAX6796) T/S, ILOAD = 300mA (Note 3) -100 L/M, ILOAD = 150mA (Note 2) (MAX6791– L/M, ILOAD = 10mA (Note 2) MAX6794) T/S, ILOAD = 150mA (Note 3) Guaranteed Output Current (Note 4) MAX6795/MAX6796, inferred from dropout test 300 MAX6791–MAX6794, inferred from dropout test 150 UNITS V V mV +100 84 130 1200 1800 1700 2400 1000 1800 84 130 1700 2400 nA mV mA Dual Mode is a trademark of Maxim Integrated Products, Inc. _______________________________________________________________________________________ 3 MAX6791–MAX6796 ELECTRICAL CHARACTERISTICS (continued) MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions ELECTRICAL CHARACTERISTICS (continued) (VIN = 14V, CIN = 1µF, COUT = 10µF, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = TJ = +25°C.) (Note 1) PARAMETER SYMBOL Short-Circuit Output Current Limit (Note 4) MIN TYP MAX6795/MAX6796, output shorted, VIN = 6V CONDITIONS 400 480 MAX6791–MAX6794, output shorted, VIN = 6V 200 240 MAX mA Thermal-Shutdown Temperature +165 Thermal-Shutdown Hysteresis °C 20 Line Regulation °C 8V ≤ VIN ≤ 72V, ILOAD = 1mA 1 8V ≤ VIN ≤ 72V, ILOAD = 10mA 1 IOUT = 1mA to 300mA (MAX6795/MAX6796) 2 IOUT = 1mA to 150mA (MAX6791–MAX6794) 1.5 Load Regulation (Note 5) Power-Supply Rejection Ratio Startup Response Time Output Overvoltage Protection Threshold UNITS % of VOUT % PSRR tSTART OVTH Output Overvoltage Protection Sink Current ILOAD = 10mA, f = 100Hz, VIN = 500mVP-P 69 ILOAD = 300mA, VOUT = 5V, OUT = 90% of its nominal value 180 µs ILOAD = 150mA, VOUT = 5V, OUT1/OUT2 = 90% of its nominal value IN to GATEP Clamp Voltage IGATEP = -100µA, VIN = 20V IN to GATEP Drive Voltage IGATEP = 0, VIN = 20V VIL ENABLE/ENABLE1/ENABLE2/ HOLD Input-Voltage High VIH 360 1.05 x VOUT ISINK = 1mA from OUT/OUT1/OUT2 VOUT = VOUT (nominal) x 1.15 ENABLE/ENABLE1/ENABLE2/ HOLD Input-Voltage Low dB 1.1 x VOUT V 5 10 13.8 16.3 18.8 V 8 10 12 V 0.4 V 1.4 mA V ENABLE/ENABLE1/ENABLE2 Input Pulldown Current Enable is internally pulled down to GND 0.5 µA HOLD Input Pullup Current HOLD is internally pulled to OUT/OUT1 2 µA 4 _______________________________________________________________________________________ High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions (VIN = 14V, CIN = 1µF, COUT = 10µF, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = TJ = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX L 4.500 4.625 4.750 M 4.250 4.375 4.500 T 2.970 3.053 3.135 S 2.805 2.888 2.970 Z 2.250 2.313 2.375 Y 2.125 2.188 2.250 W 1.620 1.665 1.710 V 1.530 1.575 1.620 L/T/Z/W 0.90 x VOUT 0.925 x VOUT 0.95 x VOUT M/S/Y/V 0.85 x VOUT 0.875 x VOUT 0.90 x VOUT UNITS RESET OUTPUT Reset Threshold (Preset Output Voltage) SET/SET1 = GND Reset Threshold (Adjustable Output Voltage) OUT to Reset Delay VOUT1/VOUT falling D0 Reset Timeout Period (CSRT = OUT/OUT1) tRP VOUT1/VOUT rising CSRT Ramp Current CSRT Ramp Threshold V V 35 µs 35 µs D1 2.187 3.125 4.063 D2 8.75 12.5 16.25 D3 35 50 65 D4 140 200 260 800 1000 1250 nA 1.185 1.218 1.255 V 280.0 400.0 520.0 170 236.2 290 ms WATCHDOG INPUT Normal Watchdog Timeout Period tWD2 Fast Watchdog Timeout Period SET Ratio = 8 tWD1 Fast Watchdog Timeout Period SET Ratio = 16 tWD1 Fast Watchdog Timeout Period SET Ratio = 64 tWD1 Fast Watchdog Minimum Period tWD0 CSWT = OUT/OUT1 (fixed) CSWT = 1500pF (adjustable) CSWT = OUT/OUT1 (fixed) 37.5 50.0 62.5 CSWT = 1500pF (adjustable) 21.95 29.52 36.90 CSWT = OUT/OUT1 (fixed) 18.75 25.0 31.25 CSWT = 1500pF (adjustable) 10.80 14.76 18.45 CSWT = OUT/OUT1 (fixed) 4.68 6.25 7.81 CSWT = 1500pF (adjustable) 2.52 3.69 4.62 2000 ms ms ms ms ns CSWT Ramp Current Adjustable timeout 800 1000 1250 nA CSWT Ramp Threshold Adjustable timeout 1.185 1.218 1.255 V Undercurrent Threshold for Watchdog Enable 7.0 10 13.8 mA Undercurrent Threshold for Watchdog Disable 3 5 7 mA _______________________________________________________________________________________ 5 MAX6791–MAX6796 ELECTRICAL CHARACTERISTICS (continued) MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions ELECTRICAL CHARACTERISTICS (continued) (VIN = 14V, CIN = 1µF, COUT = 10µF, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = TJ = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS LOGIC INPUT (WDS0, WDS1, WD-DIS, WDI) Input-Voltage Low VIL Input-Voltage High VIH Input Current 0.4 1.4 Inputs connected to OUT/OUT1 or GND V V -100 +100 nA POWER-FAIL COMPARATOR PFI Threshold VPFI 1.199 PFI Hysteresis 1.231 1.263 0.5 PFI Input Current VPFI = 14V PFI to PFO Delay (VPFI + 50mV) to (VPFI - 50mV) -100 V % +100 35 nA µs LOGIC OUTPUT (RESET, PFO) Output-Voltage Low (Open Drain or Push-Pull) Output-Voltage High (Push-Pull) Open-Drain Leakage Note 1: Note 2: Note 3: Note 4: Note 5: 6 VOL VOH ISINK = 50µA (output asserted) 0.3 ISINK = 3.2mA (output asserted) 0.4 VOUT ≥ 1.0V, ISOURCE = 10µA (output not asserted) 0.8 x VOUT VOUT ≥ 1.5V, ISOURCE = 100µA (output not asserted) 0.8 x VOUT VOUT ≥ 2.2V, ISOURCE = 500µA (output not asserted) 0.8 x VOUT V RESET = V PFO = 12V (output not asserted) V 100 All devices are 100% production tested at TJ = +25°C and +125°C. Limits at -40°C are guaranteed by design. Dropout voltage is defined as (VIN - VOUT) when VOUT is 98% of VOUT for VIN = 8V. Dropout voltage is defined as (VIN - VOUT) when VOUT is 98% of VOUT for VIN = 6V. Operation beyond the absolute maximum power dissipation is not guaranteed and may damage the part. Test at VIN = 8V (L/M), VIN = 6V (T/S), VIN = 5V (Z/Y/W/V). _______________________________________________________________________________________ V nA High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions MAX6791 NO LOAD 60 55 50 ILOAD = 100mA 100 ILOAD = 50mA 90 ILOAD = 1mA 80 MAX6793/MAX6794 35 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 70 110 40 MAX6791 toc02 75 SUPPLY CURRENT (µA) 120 MAX6791-96 toc01 80 65 SHUTDOWN SUPPLY CURRENT vs. SUPPLY VOLTAGE SUPPLY CURRENT vs. TEMPERATURE ILOAD = 0 70 30 25 20 15 60 45 MAX6791-96toc03 SUPPLY CURRENT vs. SUPPLY VOLTAGE MAX6791 50 15 25 35 45 55 65 75 5 15 25 35 45 TEMPERATURE (°C) SUPPLY VOLTAGE (V) SHUTDOWN SUPPLY CURRENT vs. TEMPERATURE NORMALIZED RESET THRESHOLD vs. TEMPERATURE DROPOUT VOLTAGE vs. TEMPERATURE 30 25 MAX6796 1.010 1.000 0.990 MAX6792 VOUT = 5V 1400 1200 ILOAD = 100mA 1000 800 600 400 ILOAD = 10mA 0.980 -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. TEMPERATURE OUTPUT VOLTAGE vs. INPUT VOLTAGE 1200 1000 ILOAD = 150mA 800 ILOAD = 100mA MAX6791-96 toc09 MAX6791-96toc08 4.988 6.0 MAX6796 VIN = 14V 5.5 VOUT = 5V 5.0 4.987 4.986 VOUT (V) DROPOUT VOLTAGE (mV) 1400 MAX6795 PRESET VOLTAGE, NO LOAD 4.989 OUTPUT VOLTAGE (V) ILOAD = 300mA OUTPUT VOLTAGE vs. LOAD CURRENT 4.990 MAX6791toc07 MAX6796 1600 4.985 4.984 4.5 4.0 VOUT = 3.3V 3.5 4.983 3.0 4.982 400 200 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 2000 600 75 ILOAD = 150mA 200 20 65 1600 DROPOUT VOLTAGE (mV) 35 1.020 MAX6791toc05 MAX6791toc04 MAX6795 VIN = 14V 1800 55 SUPPLY VOLTAGE (V) 40 SHUTDOWN SUPPLY CURRENT (µA) 10 -40 -25 -10 5 20 35 50 65 80 95 110 125 NORMALIZED RESET THRESHOLD 5 MAX6791toc06 40 ILOAD = 10mA 2.5 4.981 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) SET EXTERNALLY 2.0 4.980 0 5 15 25 35 45 55 INPUT VOLTAGE (V) 65 75 0 50 100 150 200 250 300 LOAD CURRENT (mA) _______________________________________________________________________________________ 7 MAX6791–MAX6796 Typical Operating Characteristics (VIN = VEN = 14V, CIN = 0.1µF, COUT = 10µF, TJ = TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VIN = VEN = 14V, CIN = 0.1µF, COUT = 10µF, TJ = TA = +25°C, unless otherwise noted.) NORMALIZED RESET TIMEOUT PERIOD vs. TEMPERATURE 1.02 PSRR (dB) 1.00 -55 -60 -65 -70 0.99 -75 0.98 -80 -40 -25 -10 5 20 35 50 65 80 95 110 125 100 10k 1k FREQUENCY (Hz) NORMALIZED WATCHDOG TIMEOUT PERIOD vs. TEMPERATURE NORMALIZED PFI THRESHOLD vs. TEMPERATURE 1.015 1.010 1.005 1.000 0.995 0.990 100k 1.001 MAX6791toc13 MAX6796 MAX6796 NORMALIZED PFI THRESHOLD MAX6791toc12 1.000 0.999 0.998 0.997 0.996 0.985 0.995 0.980 -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) RESET OUTPUT vs. SOURCE CURRENT RESET OUTPUT VOLTAGE vs. SINK CURRENT MAX6796 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.8 0.7 0.6 0.5 0.4 0.3 1.0 0.2 0.5 0.1 0 MAX6796 0.9 RESET OUTPUT VOLTAGE (V) 4.5 MAX6791-96toc14 5.0 MAX6791-96toc15 NORMALIZED WATCHDOG TIMEOUT PERIOD 10 TEMPERATURE (°C) 1.020 0 0 2 4 6 8 10 SOURCE CURRENT (mA) 8 VIN = 6V VOUT = 1.8V ILOAD = 10mA -45 -50 1.01 MAX6791toc11 MAX6796 NORMALIZED RESET TIMEOUT PERIOD PSRR vs. FREQUENCY -40 MAX6791toc10 1.03 RESET OUTPUT (V) MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions 12 14 0 1 2 3 4 5 6 7 SINK CURRENT (mA) _______________________________________________________________________________________ 8 9 10 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions RESET TIMEOUT PERIOD vs. CCSRT WATCHDOG TIMEOUT PERIOD vs. CCSWT WATCHDOG TIMEOUT PERIOD 1000 10,000 100 10 1 0.001 0.01 0.1 1000 100 10 1 0.0001 0.1 0.0001 MAX6791-96toc17 100,000 MAX6791-96toc16 1 0.001 0.01 0.1 CCSWT (µF) CCSRT (µF) LOAD-TRANSIENT RESPONSE LOAD-TRANSIENT RESPONSE MAX6791-96toc18 MAX6796 COUT = 10µF VOUT = 5V VIN = 14V IOUT1 MAX6796 VIN = 14V VOUT = 5V IOUT 100mA/div 100mA/div 1mA OUT1 MAX6791-96toc19 RESET TIMEOUT PERIOD (ms) 10,000 1mA 1V/div 500mV/div OUT VOUT ACCOUPLED OUT ACCOUPLED 400µs/div 400µs/div LINE-TRANSIENT RESPONSE MAX6791-96toc20 MAX6796 ILOAD = 10mA 10V/div (AC-COUPLED) VIN OUT 20mV/div OUT ACCOUPLED 1ms/div _______________________________________________________________________________________ 9 MAX6791–MAX6796 Typical Operating Characteristics (continued) (VIN = VEN = 14V, CIN = 0.1µF, COUT = 10µF, TJ = TA = +25°C, unless otherwise noted.) MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions Typical Operating Characteristics (continued) (VIN = VEN = 14V, CIN = 0.1µF, COUT = 10µF, TJ = TA = +25°C, unless otherwise noted.) LOAD-TRANSIENT RESPONSE LOAD-TRANSIENT RESPONSE MAX6791-96toc21 MAX6791-96toc22 100mA/div IOUT1 100mA/div IOUT1 20mA 1mA OUT1 AC-COUPLED 500mV/div OUT1 AC-COUPLED 500mV/div MAX6792 OUT1 = 5V COUT = 10µF MAX6792 OUT1 = 5V COUT = 10µF 1ms/div 1ms/div Pin Description PIN MAX6791/ MAX6793/ MAX6792 MAX6794 10 MAX6795/ MAX6796 NAME FUNCTION 1, 2 1, 2 — OUT1 Regulator 1 Output. Fixed (+1.8V, +2.5V, +3.3V, or +5V) or adjustable (+1.8V to +11V). OUT1 = 150mA (max). Connect a 10µF (min) capacitor from OUT1 to GND. 3 3 — SET1 Feedback Input for Setting the OUT1 Voltage. Connect SET1 to GND to select the preset output voltage. Connect to an external resistive divider for adjustable output operation. 4 4 4 PFO Active-Low, Open-Drain, Power-Fail Comparator Output. PFO asserts low when PFI is below the internal 1.231V threshold. PFO deasserts when PFI is above the internal 1.231V threshold. 5 5 5 CSWT Watchdog Timeout Period Adjust Input. Connect CSWT to OUT1/OUT for the internally fixed watchdog timeout period. For adjustable watchdog timeout period, connect a capacitor from CSWT to GND. See the Selecting Watchdog Timeout Period section for more details. 6 6 6 CSRT Reset Timeout Period Adjust Input. Connect CSRT to OUT1/OUT for the internally fixed timeout period. For adjustable timeout, connect a capacitor from CSRT to GND. See the Reset Output section for more details. 7 7 7 GND Ground 8 8 8 RESET Active-Low Reset Output. RESET remains low while OUT1/OUT is below the reset threshold. RESET remains low for the duration of the reset timeout period after the reset conditions end. RESET is available in push-pull and open-drain options. ______________________________________________________________________________________ High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions PIN MAX6791/ MAX6793/ MAX6792 MAX6794 MAX6795/ MAX6796 NAME 9 — — WDS1 10 — — WDS0 11 11 11 FUNCTION Min/Max Watchdog Logic-Select Input. WDS0 and WDS1 select the watchdog window ratio or disable the watchdog timer. Drive WDS0 and WDS1 high or low to select the desired ratio, see Table 4. WDI Watchdog Input. MAX6793–MAX6796: A falling or rising transition must occur on WDI within the selected watchdog timeout period or a reset pulse occurs. The watchdog timer clears when a transition occurs on WDI or whenever RESET is asserted. MAX6791/MAX6792: WDI falling and rising transitions within periods shorter than tWD1 or longer than tWD2 force RESET to assert low for the reset timeout period. The watchdog timer begins to count after RESET is deasserted. The watchdog timer clears when a valid transition occurs on WDI or whenever RESET is asserted. Connect WDS0 high and WDS1 low to disable the watchdog timer function. See the Watchdog Timer section. 12 12 12 HOLD Active-Low Regulator Hold Input. When HOLD is forced low, OUT1/OUT remains ON even if ENABLE1/ENABLE is pulled low. To shut down the output of the regulator (OUT/OUT1), release HOLD after ENABLE1/ENABLE is pulled low. Connect HOLD to OUT1/OUT or leave unconnected if unused. HOLD is internally connected to OUT/OUT1 through a 2µA current source. 13, 14 13, 14 — OUT2 Regulator 2 Output. OUT2 is a fixed +5V output. Connect a 10µF (min) capacitor from OUT2 to GND. 15 15 — ENABLE2 16 16 16 PFI Adjustable Power-Fail Comparator Input. Connect PFI to a resistive-divider to set the desired PFI threshold. The PFI input is referenced to an accurate 1.231V threshold. 17, 18 17, 18 17, 18 IN Regulator Inputs. Bypass IN with a 1µF capacitor to GND. 19 19 19 GATEP 20 20 — ENABLE1 — 9 9 WD-DIS Active-High Enable Input 2. Drive ENABLE2 high to turn on OUT2. ENABLE2 is internally connected to ground through a 0.5µA current sink. pFET Gate Drive. Connect GATEP to the gate of a p-channel MOSFET to provide low drop reverse-battery voltage protection. Active-High Enable Input 1. Drive ENABLE1 high to turn on OUT1. ENABLE1 is internally connected to ground through a 0.5µA current sink. Watchdog Disable Input. Drive WD-DIS low to disable the watchdog timer. Drive WD-DIS high or connect to OUT/OUT1 to enable the watchdog timer. The watchdog timer clears when reset asserts. ______________________________________________________________________________________ 11 MAX6791–MAX6796 Pin Description (continued) MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions Pin Description (continued) PIN MAX6791/ MAX6793/ MAX6792 MAX6794 MAX6795/ MAX6796 NAME FUNCTION — 10 10, 13, 14, 15 N.C. Not Internally Connected — — 1, 2 OUT Regulator Output. Fixed +5V, +3.3V, +2.5V, +1.8V, or adjustable output (+1.8V to +11V). Connect a 10µF (min) capacitor from OUT to GND. — — 3 SET Feedback Input for Setting the OUT Voltage. Connect SET to GND to select the preset output voltage. Connect to an external resistive-divider for adjustable output operation. — — 20 ENABLE Active-High Enable Input. Drive ENABLE high to turn on the regulator. ENABLE is internally connected to ground through a 0.5µA current sink. — — — EP Exposed Pad. EP is internally connected to GND. Connect EP to the ground plane to provide a low thermal-resistance path from the IC junction to the PC board. Do not use as the electrical connection to GND. Detailed Description The MAX6791–MAX6796 ultra-low-quiescent-current, single-/dual-output, high-input-voltage linear regulators operate from 5V to 72V. The MAX6791–MAX6794 feature dual regulators that deliver up to 150mA of load current per output. One output is available with preset output-voltage options (+1.8V, +2.5V, +3.3V, and +5.0V) and can be adjusted to any voltage between +1.8V to +11V using an external resistive-divider at SET1. The other output provides a fixed 5V output voltage. The MAX6795/MAX6796 feature a single regulator that delivers up to 300mA of current with preset outputvoltage options (+1.8V, +2.5V, +3.3V, and +5.0V) or can be adjusted to any voltage between +1.8V to +11V. All devices include an integrated µP reset circuit with a fixed/adjustable reset and watchdog timeout period. The MAX6791–MAX6796 monitor OUT/OUT1 and assert a reset output when the output falls below the reset threshold. +5V, or an adjustable output voltage of +1.8V to +11V, selected using an external resistive-divider network connected between OUT1/OUT, SET1/SET, and GND (see Figure 1). In addition to an adjustable output, the MAX6791–MAX6794 feature a fixed 5V output voltage. Reset Output The reset output is typically connected to the reset input of a µP. A µP’s reset input starts or restarts the µP in a known state. The MAX6791–MAX6796 supervisory circuits provide the reset logic output to prevent codeexecution errors during power-up, power-down, and brownout conditions (see the Typical Application Circuit). RESET changes from high to low whenever the monitored output voltage drops below the reset threshold voltage or the watchdog timeout expires. Once the monitored voltage exceeds its respective reset threshold voltage, RESET remains low for the reset timeout period, then goes high. Regulators The single and dual regulators accept an input voltage from 5V to 72V. The MAX6791–MAX6796 offer fixed preset output voltages of +1.8V, +2.5V, +3.3V, and 12 ______________________________________________________________________________________ High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions ENABLE2 MAX6791/MAX6792 OUT2 THERMAL PROTECTION OUT1 IN GATEP ENABLE1 HOLD OVERCURRENT PROTECTION CONTROL LOGIC 1.23V SET1 124mV 1.138V OR 1.076V RESET TIMEOUT RESET CSRT WATCHDOG TIMEOUT WDI CSWT RESET WDS0 WDS1 PFO GND PFI ______________________________________________________________________________________ 13 MAX6791–MAX6796 Functional Diagrams High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions MAX6791–MAX6796 Functional Diagrams (continued) ENABLE2 MAX6793/MAX6794 OUT2 THERMAL PROTECTION OUT1 IN GATEP ENABLE1 HOLD OVERCURRENT PROTECTION CONTROL LOGIC 1.23V SET1 124mV 1.138V OR 1.076V RESET TIMEOUT RESET CSRT WATCHDOG TIMEOUT WDI CSWT RESET WD-DIS PFO GND 14 PFI ______________________________________________________________________________________ High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions THERMAL PROTECTION MAX6795/MAX6796 OUT IN GATEP ENABLE HOLD OVERCURRENT PROTECTION CONTROL LOGIC 1.23V SET 124mV 1.138V OR 1.076V RESET TIMEOUT RESET CSRT WATCHDOG TIMEOUT WDI CSWT RESET WD-DIS PFO GND PFI ______________________________________________________________________________________ 15 MAX6791–MAX6796 Functional Diagrams (continued) MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions Watchdog Timer The MAX6791–MAX6796 include a watchdog timer that asserts RESET if the watchdog input (WDI) does not toggle high to low or low to high within the watchdog timeout period t WD (280ms min or externally adjustable). RESET remains low for the fixed or useradjustable 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 t RP , deasserted for tWD, until WDI is toggled again. Once RESET asserts, it stays low for the entire reset timeout period ignoring any WDI transitions that may occur. To prevent the watchdog from asserting RESET, toggle WDI with a valid rising or falling edge before tWD from the last edge. The watchdog counter clears when WDI toggles prior to tWD from the last edge or when RESET asserts. The watchdog resumes counting after RESET deasserts. The MAX6791/MAX6792 have a windowed watchdog timer that asserts RESET for the adjusted reset timeout period when the watchdog recognizes a fast watchdog fault (tWDI < tWD1), or a slow watchdog fault (tWDI > tWD2). The reset timeout period is adjusted independently of the watchdog timeout period. Enable and Hold Inputs The MAX6791–MAX6796 support two logic inputs, ENABLE1/ENABLE and HOLD, making these devices suitable for automotive applications. For example, when the ignition key signal drives ENABLE1/ENABLE high, the regulator turns on and remains on even if ENABLE1/ENABLE goes low, as long as HOLD is forced low and stays low after initial regulator power-up. In this state, releasing HOLD turns the regulator output (OUT/OUT1) off. This feature makes it possible to implement a self-holding circuit without external components. Forcing ENABLE1/ENABLE low and HOLD high or unconnected places the MAX6791–MAX6796 into shutdown mode in which the MAX6791–MAX6796 draw less than 27µA of supply current. Table 3 shows the state of the regulator output with respect to the voltage level at ENABLE1/ENABLE and HOLD. Connect HOLD to OUT1/OUT or leave it unconnected to allow the ENABLE1/ENABLE input to act as a standard ON/OFF switch for the regulator output (OUT/OUT1). Power-Fail Comparator PFI is the noninverting input to a comparator. If PFI is less than VPFI (1.231V), PFO goes low. Common uses for the power-fail comparator include monitoring the 16 preregulated input of the power supply (such as a battery) or providing an early power-fail warning so software can conduct an orderly system shutdown. Set the power-fail threshold with a resistive-divider, as shown in Figure 5. The typical comparator delay is 35µs from PFI to PFO. Connect PFI to GND or IN if unused. Reverse-Battery Protection Circuitry The MAX6791–MAX6796 include an overvoltage protection circuit that is capable of driving a p-channel MOSFET to protect against reverse-battery conditions. This MOSFET eliminates the need for external diodes, thus minimizing the input voltage drop. See the Typical Application Circuit. The low p-channel MOSFET onresistance of 30mΩ or less yields a forward-voltage drop of only a few millivolts versus hundreds of millivolts for a diode, thus improving efficiency in batteryoperated devices. Connecting a positive battery voltage to the drain of Q1 (see the Typical Application Circuit) forward biases its body diode. When the source voltage exceeds Q1’s threshold voltage, Q1 turns on. Once the FET is on, the battery is fully connected to the system and can deliver power to the device and the load. An incorrectly inserted battery reverse-biases the FET’s body diode. The gate remains at the ground potential. The FET remains off and disconnects the reversed battery from the system. The internal zener diode and resistor combination at GATEP prevent damage to the p-channel MOSFET during an overvoltage condition. See the Functional Diagrams. Thermal Protection When the junction temperature exceeds TJ = +165°C, the internal protection circuit turns off the internal pass transistor and allows the IC to cool. The thermal sensor turns the pass transistor on again after the junction temperature drops to +145°C, resulting in a cycled output during continuous thermal-overload conditions. Thermal protection protects the MAX6791–MAX6796 in the event of fault conditions. For continuous operation, do not exceed the absolute maximum junction temperature rating of +150°C. Proper Soldering of Package Heatsink The MAX6791–MAX6796 package features an exposed thermal pad on its underside that should be used as a heatsink. This pad lowers the package’s thermal resistance by providing a direct heat-conduction path from the die to the PC board. Connect the exposed pad and GND to the system ground using a large pad or ground plane, or multiple vias to the ground plane layer. ______________________________________________________________________________________ High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions Output Voltage Selection The MAX6791–MAX6796 feature dual-mode operation: these devices operate in either a preset voltage mode or an adjustable mode. In preset voltage mode, internal trimmed feedback resistors set the internal linear regulator to +1.8V, +2.5V, +3.3V, or +5V (see the Selector Guide). Select preset voltage mode by connecting SET1 (MAX6791–MAX6794)/SET(MAX6795/MAX6796) to GND. In adjustable mode, select an output voltage between +1.8V and +11V using two external resistors connected as a voltage-divider to SET1/SET (see Figure 1). Set the output voltage using the following equation: R1 VOUT = VSET 1 + R2 where VSET = 1.2315V and R1, R2 ≤ 200kΩ. Selecting Reset Timeout Period The reset timeout period is adjustable to accommodate a variety of µP applications. Adjust the reset timeout period by connecting a capacitor between CSRT and GND. Use the following formula to set the reset timeout period: V tRP = CCSRT 1.218 × 106 A where tRP is in seconds and CCSRT is in Farads. Connect CSRT to OUT1 (MAX6791–MAX6794) or to OUT (MAX6795/MAX6796) to select an internally fixed timeout period. Connect CSRT to GND to force RESET low. C CSRT must be a low-leakage (< 10nA) type capacitor. Ceramic capacitors are recommended; do not use capacitors lower than 100pF to avoid the influence of parasitic capacitances. Available Output-Current Calculation VIN IN OUT1/OUT R1 MAX6791–MAX6796 SET1/SET R2 GND Figure 1. Setting the Output Voltage Using a Resistive-Divider IOUT vs. (VIN - VOUT) 350 VOUT = 1.8V 300 +70°C SAFE OPERATION REGION FOR EACH TEMPERATURE POINT IS UNDER THE CURVE +85°C 250 IOUT (mA) The MAX6791–MAX6794 provide up to 150mA per output, and the MAX6795/MAX6796 provide up to 300mA of load current. Since the input voltage can be as high as +72V, package power dissipation limits the amount of output current available for a given input/output voltage and ambient temperature. Figure 2 shows the maximum power-dissipation curve for the MAX6791– MAX6796. The graph assumes that the exposed metal pad of the device package is soldered to a solid 1in2 section of PC board copper. Use Figure 2 to determine the allowable package dissipation for a given ambient temperature. Alternately, use the following formula to calculate the allowable package dissipation: PDMAX = Maximum Power Dissipation PDMAX = 2.666W, for TA ≤ +70°C PDMAX = [2.666W - 0.0333W x (TA - 70°C)], for +70°C < TA ≤ +125°C where 0.0333W is the MAX6791–MAX6796 package thermal derating in W/°C and TA is the ambient temperature in °C. After determining the allowable package dissipation, calculate the maximum output current using the following formula: PD = Power Dissipation 200 150 PD < PDMAX where PD = [(IN - OUT1) x IOUT1] + [(IN OUT2) x IOUT2], for MAX6791–MAX6794. 100 Also, IOUT1 should be ≤ 150mA and IOUT2 should be ≤ 150mA in any case. PD < PD MAX where PD = [(IN - OUT) x I OUT ], for MAX6795/MAX6796. Also, IOUT should be ≤ 300mA in any case. 50 +125°C 0 0 10 20 30 40 50 60 70 75 (VIN - VOUT) (V) Figure 2. Maximum Power Dissipation for MAX6791–MAX6796 ______________________________________________________________________________________ 17 MAX6791–MAX6796 Applications Information MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions Selecting Watchdog Timeout Period The watchdog timeout period is adjustable to accommodate a variety of µP applications. With this feature, the watchdog timeout can be optimized for software execution. The programmer can determine how often the watchdog timer should be serviced. Adjust the watchdog timeout period (tWD) by connecting a capacitor between CSWT and GND. For normal-mode operation, calculate the watchdog timeout capacitor as follows: V t WD2 = CCSWT 155 × 106 A where tWD is in seconds and CCSWT is in Farads. To select the internally fixed watchdog timeout period for the MAX6791–MAX6794, connect CSWT to OUT1. To select the internally fixed watchdog timeout period for the MAX6795/MAX6796, connect CSWT to OUT. CCSWT must be a low-leakage (< 10nA) type capacitor. Ceramic capacitors are recommended; do not use capacitors lower than 100pF to avoid the influence of parasitic capacitances. The MAX6791/MAX6792 have a windowed watchdog timer that asserts RESET for tRP when the watchdog recognizes a fast watchdog fault (time between transitions < tWD1), or a slow watchdog fault (time between transitions > tWD2). The reset timeout period is adjusted independently of the watchdog timeout period. The slow watchdog period, tWD2, is calculated as follows: V t WD2 = CCSWT 155 × 106 A where tWD2 is in seconds and CCSWT is in Farads. tWD0 RESET: MIN tWD1 MAX GUARANTEED TO ASSERT The fast watchdog period, tWD1, is selectable as a ratio from the slow watchdog fault period (tWD2). Select the fast watchdog period by connecting WDS0 and WDS1 to OUT/OUT1 or GND according to Table 4, which illustrates the settings for the 8, 16, and 64 window ratios (t WD2/t WD1). For example, if C CSWT is 2000pF, and WDS0 and WDS1 are low, then tWD2 is 318ms (typ) and tWD1 is 40ms (typ). RESET asserts if the watchdog input has two edges too close to each other (faster than tWD1); or has edges that are too far apart (slower than tWD2). All WDI inputs are ignored while RESET is asserted. The watchdog timer begins to count after RESET is deasserted. If the time difference between two transitions on WDI is shorter than tWD1 or longer than tWD2, RESET is forced to assert low for the reset timeout period. If the time difference between two transitions on WDI is between tWD1 (min) and tWD1 (max) or tWD2 (min) and tWD2 (max), RESET is not guaranteed to assert or deassert; see Figure 3. To guarantee that the window watchdog does not assert RESET, strobe WDI between t WD1 (max) and t WD2 (min). The watchdog timer is cleared when RESET is asserted. Disable the watchdog timer by connecting WDS0 high and WDS1 low. There are several options available to disable the watchdog timer (for system development or test purposes or when the µP is in a low-power sleep mode). One way to disable the watchdog timer is to drive WD-DIS low for the MAX6793–MAX6796 and drive WDS0 high and WDS1 low for the MAX6791/MAX6792. This prevents the capacitor from ramping up. Finally, reducing the OUT/OUT1 regulator current below the specified regulator current watchdog-disable threshold (3mA min) also disables the watchdog timer. The MIN tWD2 MAX GUARANTEED TO NOT ASSERT UNDETERMINED GUARANTEED TO ASSERT UNDETERMINED WDI INPUT: FAST FAULT NORMAL OPERATION SLOW FAULT Figure 3. Windowed Watchdog Timing Diagram 18 ______________________________________________________________________________________ High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions VIN IN Capacitor Selection and Regulator Stability For stable operation over the full temperature range and with load currents up to 150mA, use a 10µF (min) output capacitor with an ESR < 0.5Ω. To reduce noise and improve load-transient response and power-supply rejection, use larger output-capacitor values. Some ceramic dielectrics exhibit large capacitance and ESR variation with temperature. For these types of capacitors (such as Z5U and Y5V), much higher-value capacitors are required to maintain stability over the temperaure range. With X7R dielectrics, a 10µF capacitor should be sufficient at all operating temperatures. To improve power-supply rejection and transient response, increase the capacitor between IN and GND. MAX6792 MAX6794 MAX6796 RESET GND Figure 4. Ensuring RESET Valid to VIN = 0V VIN Ensuring a Valid RESET Output Down to VIN = 0 When VIN falls below 1V, RESET current-sinking capabilities decline drastically. High-impedance CMOSlogic inputs connected to RESET can drift to undetermined voltages. This presents no problems in most applications, since most µPs and other circuitry do not operate with a supply voltage below 1V. In those applications where RESET must be valid down to 0, adding a pulldown resistor between RESET and GND sinks any stray leakage currents, holding RESET low (Figure 4). The value of the pulldown resistor is not critical; 100kΩ is large enough not to load RESET and small enough to pull RESET to ground. Open-drain RESET versions are not recommended for applications requiring valid logic for VIN down to 0. Adding Hysteresis to PFI The power-fail comparator has a typical input hysteresis of 0.5% (of VTH). This is sufficient for most applications where a power-supply line is being monitored through an external resistive-divider (Figure 5). Figure 6 shows how to add hysteresis to the power-fail comparator. Select the ratio of R5 and R6 so PFI sees 1.23V when VIN falls to the desired trip point (VTRIP). Since PFO is an open-drain output, resistors R7 and R8 add hysteresis. R7 typically is an order of magnitude greater than R5 or R6. The current through R5 and R6 should be at least 10µA to ensure that the 100nA (max) PFI input current does not shift the trip point. R7 should be larger than 50kΩ to prevent it from loading down the PFO. MAX6791–MAX6796 watchdog re-enables immediately when any of these conditions are removed (as long as the RESET is not asserted). Note that the output current threshold limit includes hysteresis so that output current must exceed 13.8mA (max) to reenable the watchdog timer. VTERM IN R5 PFI MAX6791 PFO R6 GND Figure 5. Setting Power-Fail Comparator to Monitor VIN VIN R7 VTERM IN R8 R5 PFI MAX6791 PFO R6 GND Figure 6. Adding Hysteresis Power-Fail Comparator ______________________________________________________________________________________ 19 MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions Table 1. Preset Output Voltage and Reset Threshold PART SUFFIX (_) OUTPUT VOLTAGE (V) RESET THRESHOLD (NOMINAL) L 5.0 4.625 M 5.0 4.375 T 3.3 3.053 S 3.3 2.888 Z 2.5 2.313 Y 2.5 2.188 W 1.8 1.665 V 1.8 1.575 Use the following formulas to determine the high/low threshold levels and the hysteresis: VL-H = VPFI x (1 + R5 / R6 +R5 / R7) VH-L = VPFI x (1 + R5 / R6 ) + (VPFI - VTERM) [R5 / (R7 + R8)] VHYS = VPFI x (R5 / R7 ) - (VPFI - VTERM) [R5 / (R7 + R8)] where VL-H is the threshold level for the monitored voltage rising and VH-L is the threshold level for the monitored voltage falling. Chip Information PROCESS: BiCMOS Table 2. Preset Timeout Period PART SUFFIX (_) RESET TIMEOUT PERIOD (NOMINAL) D0 35µs D1 3.125ms D2 12.5ms D3 50ms D4 200ms Table 3. ENABLE/ENABLE1 and HOLD Truth Table/State Table OPERATING STATE ENABLE1/ ENABLE HOLD REGULATOR 1 OUTPUT COMMENT Initial state Low Don’t care Off ENABLE/ENABLE1 is pulled to GND through internal pulldown. OUT/OUT1 is disabled. Turn-on state High Don’t care On ENABLE/ENABLE1 is externally driven high turning OUT/OUT1 on. HOLD is pulled up to OUT/OUT1. Hold setup state High Low On HOLD is externally pulled low while ENABLE/ENABLE1 remains high, and the regulator latches on. Hold state Low Low On ENABLE/ENABLE1 is driven low (or allowed to float low by an internal pulldown). HOLD remains externally pulled low keeping OUT/OUT1 on. Off state Low High (floats high) Off HOLD is driven high (or allowed to float high by the internal pullup) while ENABLE/ENABLE1 is low. OUT/OUT1 is turned off and ENABLE/ENABLE1 and HOLD logic returns to the initial state. 20 ______________________________________________________________________________________ High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions MAX6791–MAX6796 Table 4. MIN/MAX Watchdog Setting WDS0 WDS1 RATIO 0 0 8 0 1 16 1 0 Watchdog disabled 1 1 64 Table 5. Standard Version Part Number PART NUMBER OUTPUT VOLTAGE (V) RESET TIMEOUT PERIOD (ms) (NOMINAL) RESET THRESHOLD (V) (NOMINAL) MAX6791TPLD2+ 5.0 12.5 4.625 MAX6791TPSD2+ 3.3 12.5 2.888 4.625 MAX6792TPLD2+ 5.0 12.5 MAX6792TPSD2+ 3.3 12.5 2.888 MAX6793TPLD2+ 5.0 12.5 4.625 MAX6793TPSD2+ 3.3 12.5 2.888 MAX6794TPLD2+ 5.0 12.5 4.625 MAX6794TPSD2+ 3.3 12.5 2.888 MAX6795TPLD2+ 5.0 12.5 4.625 MAX6795TPSD2+ 3.3 12.5 2.888 MAX6796TPLD2+ 5.0 12.5 4.625 3.3 12.5 2.888 MAX6796TPSD2+ +Denotes lead-free package. Selector Guide NUMBER OF OUTPUTS WINDOWED WATCHDOG TIMEOUT ENABLE INPUTS WATCHDOG DISABLE INPUT Open drain 2 ✓ Dual ✓ Push-pull 2 ✓ Dual ✓ Open drain 2 — Dual ✓ MAX6794TP_D_ Push-pull 2 — Dual ✓ MAX6795TP_D_ Open drain 1 — Single ✓ MAX6796TP_D_ Push-pull 1 — Single ✓ PART RESET OUTPUT MAX6791TP_D_ MAX6792TP_D_ MAX6793TP_D_ ______________________________________________________________________________________ 21 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions MAX6791–MAX6796 Typical Application Circuit 12V BATT TO OTHER CIRCUITRY GATEP IN IN ENABLE1 PFI OUT1 ENABLE2 OUT2 SET1 MAX6791/MAX6792 CSWT PFO CSRT GND WDI RESET HOLD RESET VCC INT 22 I/O WDS1 I/O WDS0 TXD µC VCC INH BATT CANH XCVR RXD CANL ______________________________________________________________________________________ High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions 11 WDI WDI 12 HOLD HOLD 13 OUT2 OUT2 14 OUT2 OUT2 15 TOP VIEW ENABLE2 ENABLE2 TOP VIEW 15 14 13 12 11 PFI 16 10 WDS0 PFI 16 10 N.C. IN 17 9 WDS1 IN 17 9 WD-DIS 8 RESET IN 18 8 RESET 7 GND 7 GND 6 CSRT 6 CSRT 3 4 5 1 CSWT OUT1 THIN QFN 5mm x 5mm 2 3 4 5 CSWT 2 PFO + SET1 1 ENABLE1 20 OUT1 + OUT1 N.C. N.C. HOLD WDI TOP VIEW N.C. THIN QFN 5mm x 5mm 15 14 13 12 11 PFI 16 10 N.C. IN 17 9 WD-DIS 8 RESET 7 GND 6 CSRT IN 18 MAX6795/MAX6796 GATEP 19 2 3 4 5 PFO CSWT 1 SET + OUT ENABLE 20 OUT ENABLE1 20 GATEP 19 PFO GATEP 19 MAX6793/MAX6794 SET1 MAX6791/MAX6792 OUT1 IN 18 THIN QFN 5mm x 5mm ______________________________________________________________________________________ 23 MAX6791–MAX6796 Pin Configurations 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.) QFN THIN.EPS MAX6791–MAX6796 High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions 24 ______________________________________________________________________________________ High-Voltage, Micropower, Single/Dual Linear Regulators with Supervisory Functions Revision History Pages changed at Rev 1: 1, 10, 11, 18, 19, 24, 25 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 ____________________ 25 © 2006 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. MAX6791–MAX6796 Package Information (continued) (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.)