Ultralow Power, 3-Lead, SOT-23 Microprocessor Reset Circuits Data Sheet ADM6326/ADM6328/ADM6346/ADM6348 FEATURES FUNCTIONAL BLOCK DIAGRAMS Ultralow supply current of 1 µA maximum (ADM6326/ADM6328) ADM6326/ADM6346 Accurate monitoring of 2.5 V, 3 V, 3.3 V, and 5 V rails Reset thresholds available in increments from 2.2 V to 4.63 V VCC RESET GENERATOR RESET Glitch immunity from negative-going VCC transients VREF (100ms) 2 reset output options Push-pull RESET (ADM6326/ADM6346) Open-drain RESET (ADM6328/ADM6348) GND 08052-001 Minimum reset timeout of 100 ms Figure 1. Operating temperature range of −40°C to +85°C 3-lead SOT-23 package ADM6328/ADM6348 APPLICATIONS VCC RESET RESET Telecommunications GENERATOR VREF (100ms) Microprocessor systems Desktop and notebook computers Portable equipment GND 08052-002 Figure 2. GENERAL DESCRIPTION The ADM6326/ADM6328/ADM6346/ADM6348 devices provide microprocessor in a reset state until conditions have stabilized. low cost solutions for protecting sensitive circuitry, such as micro- The reset output remains operational with VCC as low as 1 V. processor and telecommunications circuitry. The ADM6326 and ADM6346 have an active low push-pull reset With built-in glitch immunity, ultralow supply currents, and output. The ADM6328 and ADM6348 have an active low open- 24 reset threshold voltage options, the ADM6326/ADM6328/ drain reset output, which requires an external pull-up resistor. ADM6346/ADM6348 not only ensure that systems are immune The ADM6326 and ADM6328 offer a choice of ten reset thresholds to fast transients on V , but also that the devices are suitable in increments between 2.2 V and 3.08 V, whereas the ADM6346 CC for monitoring a variety of supply voltages in low power, and ADM6348 offer a choice of 14 reset thresholds between 3.3 V portable equipment. and 4.63 V. Not all options are released for sale as standard models. See the Ordering Guide for details. These devices provide a reset output during power-up, power- down, and brownout conditions. On power-up, an internal These devices are available in a 3-lead SOT-23 package and timer holds RESET asserted for at least 100 ms. This holds the operate over the extended temperature range of −40°C to +85°C. Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 ©2009–2018 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com

ADM6326/ADM6328/ADM6346/ADM6348 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Pin Configuration and Function Descriptions ..............................5 Applications ....................................................................................... 1 Typical Performance Characteristics ..............................................6 Functional Block Diagrams ............................................................. 1 Theory of Operation .........................................................................7 General Description ......................................................................... 1 Reset Output ..................................................................................7 Revision History ............................................................................... 2 Interfacing to Other Devices .......................................................7 Specifications ..................................................................................... 3 Transient Immunity ......................................................................7 Absolute Maximum Ratings ............................................................ 4 Outline Dimensions ..........................................................................8 Thermal Resistance ...................................................................... 4 Ordering Guide .............................................................................9 ESD Caution .................................................................................. 4 REVISION HISTORY 5/2018—Rev. A to Rev. B Changes to General Description Section ...................................... 1 Changes to Table 2 ............................................................................ 3 Added Note 1, Table 2; Renumbered Sequentially ....................... 3 Changes to Ordering Guide ............................................................ 9 6/2014—Rev. 0 to Rev. A Changes to Figure 1 and Figure 2 ................................................... 1 9/2009—Revision 0: Initial Version Rev. B | Page 2 of 9

Data Sheet ADM6326/ADM6328/ADM6346/ADM6348 SPECIFICATIONS T = −40°C to +85°C, unless otherwise noted. Typical values are at T = 25°C and V = 3 V. Overtemperature limits are guaranteed by design. A A CC Table 1. Parameter Min Typ Max Unit Test Conditions/Comments OPERATING VOLTAGE RANGE, VCC 1.0 5.5 V INPUT CURRENT, ICC 0.5 1.0 µA ADM6326/ADM6328 only, VCC = 3.0 V for VTH ≤ 2.93 V, VCC = 3.2 V for VTH > 2.93 V, no load 1.0 1.75 µA VCC = 5.5 V, no load RESET THRESHOLD Threshold Voltage, VTH (See Table 2) VTH − 2.5% VTH VTH + 2.5% V VTH − 1.5% VTH VTH + 1.5% V TA = 25°C Temperature Coefficient 40 ppm/°C Hysteresis ADM6326/ADM6328 6.3 mV ADM6346/ADM6348 9.5 mV TIMING CHARACTERISTICS VCC to Reset Delay (tRD) 20 µs VCC = VTH to (VTH − 100 mV) Reset Active Timeout Period (tRP) 100 185 280 ms RESET OUTPUT VOLTAGE LOW, VOL 0.3 V VCC > 2.1 V, ISINK = 1.6 mA, reset asserted 0.4 V VCC ≥ 1.2 V, ISINK = 100 μA, reset asserted RESET OUTPUT VOLTAGE HIGH, VOH 0.8 × VCC V ADM6326 only, VCC = 3.2 V, ISOURCE = 500 µA 0.8 × VCC V ADM6326/ADM6346 only, VCC = 4.5 V, ISOURCE = 800 µA, VTH ≤ 4.38 V 0.8 × VCC V ADM6326/ADM6346 only, VCC = VTH(MAX), ISOURCE = 800 µA, VTH ≥ 4.5 V OPEN-DRAIN RESET OUTPUT LEAKAGE CURRENT 0.1 µA Table 2. Reset Threshold Voltage TA = 25°C TA = −40°C to +85°C Parameter Min Typ Max Min Max Unit RESET THRESHOLD VOLTAGE (VTH)1 ADM6326-22, ADM6328-22 2.167 2.2 2.233 2.145 2.25 V ADM6328-23 2.285 2.32 2.355 2.262 2.375 V ADM6328-25 2.462 2.5 2.537 2.437 2.562 V ADM6326-26 2.591 2.63 2.669 2.564 2.696 V ADM6326-27, ADM6328-27 2.66 2.7 2.741 2.633 2.768 V ADM6328-28 2.758 2.8 2.842 2.73 2.87 V ADM6326-29 2.886 2.93 2.974 2.857 3.0 V ADM6326-30 2.955 3.00 3.045 2.925 3.075 V ADM6326-31 3.034 3.08 3.126 3.003 3.15 V ADM6348-33 3.25 3.3 3.35 3.217 3.383 V ADM6348-34 3.349 3.4 3.451 3.315 3.485 V ADM6348-35 3.447 3.5 3.552 3.412 3.587 V ADM6348-36 3.546 3.6 3.654 3.51 3.69 V ADM6348-37 3.644 3.7 3.755 3.607 3.792 V ADM6348-38 3.743 3.8 3.857 3.705 3.895 V ADM6348-39 3.841 3.9 3.958 3.802 3.997 V ADM6348-40 3.94 4.0 4.06 3.9 4.1 V ADM6348-41 4.038 4.1 4.161 3.997 4.202 V ADM6348-42 4.137 4.2 4.263 4.095 4.305 V ADM6348-43 4.235 4.3 4.364 4.192 4.407 V ADM6348-44 4.314 4.38 4.446 4.27 4.489 V ADM6348-45 4.432 4.5 4.567 4.387 4.612 V ADM6346-46, ADM6348-46 4.56 4.63 4.699 4.514 4.746 V 1 Not all device options are released for sale as standard models. See the Ordering Guide for full details. Rev. B | Page 3 of 9

ADM6326/ADM6328/ADM6346/ADM6348 Data Sheet ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Table 3. Parameter Rating θ is specified for the worst-case conditions, that is, a device JA Supply Voltage, V −0.3 V to +6 V soldered in a circuit board for surface-mount packages. CC Input Current, I 20 mA CC Table 4. Thermal Resistance Output Voltage Package Type θ Unit Push-Pull RESET −0.3 V to (VCC + 0.3 V) JA 3-Lead SOT-23 270 °C/W Open-Drain RESET −0.3 V to +6 V Output Current (RESET) 20 mA ESD CAUTION Rate of Rise of V 100 V/µs CC Temperature Storage −65°C to +155°C Operating −40°C to +85°C Soldering (10 sec) 300°C Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability. Rev. B | Page 4 of 9

Data Sheet ADM6326/ADM6328/ADM6346/ADM6348 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS ADM6326/ GND 1 ADM6328/ ADM6346/ ADM6348 3 VCC RESET 2 (NToOt Pto V SIEcaWle) 08052-003 Figure 3. ADM6326/ADM6328/ADM6346/ADM6348 Pin Configuration Table 5. Pin Function Descriptions Pin No. Mnemonic Description 1 GND Ground Reference for All Signals; 0 V. 2 RESET Active Low Logic Output. This pin is low when VCC is less than the reset threshold; it remains low for 185 ms (typical) after V becomes greater than the reset threshold. CC 3 V Supply Voltage Being Monitored. CC Rev. B | Page 5 of 9

ADM6326/ADM6328/ADM6346/ADM6348 Data Sheet TYPICAL PERFORMANCE CHARACTERISTICS 1.0 280 0.9 260 A) 00..78 VCVCC C= =3. 35VV UT (ms) 240 NT (µ 0.6 MEO 220 CURRE 0.5 ESET TI 128000 UPPLY 00..34 VCC = 1.4V R-UP R 160 S E W 0.2 O 140 P 0.1 120 0–40 –20 0TEMPER20ATURE(°4C0) 60 80 08052-004 100–40 –20 0TEMPER2A0TURE (°4C0) 60 80 08052-007 Figure 4. Supply Current vs. Temperature Figure 6. Power-Up Reset Timeout vs. Temperature 800 250 s) 700 TION (µ 600 AY (µs) 200 A L R E DU 500 T D 150 NSIENT 400 N RESE A W 100 R 300 O T D MUM 200 WER- VOD = 10mV XI O 50 VOD = 20mV A P M 100 VOD = 200mV VOD = 100mV 0 0 1 RESET THRES10HOLD OVERDRIVE,1 V00TH – VCC (mV) 1000 08052-006 –40 –20 0TEMPER2A0TURE (°4C0) 60 80 08052-005 Figure 5. Maximum Transient Duration vs. Reset Threshold Overdrive Figure 7. Power-Down Reset Delay vs. Temperature Rev. B | Page 6 of 9

Data Sheet ADM6326/ADM6328/ADM6346/ADM6348 THEORY OF OPERATION The ADM6326/ADM6328/ADM6346/ADM6348 are designed INTERFACING TO OTHER DEVICES to protect the integrity of a system’s operation by ensuring the The active low, open-drain reset output of the ADM6328 and proper operation of the system during power-up, power-down, ADM6348 makes these devices ideal for integration with devices and brownout conditions. Ultralow supply currents make these such as microprocessors with bidirectional reset pins. Simply devices particularly suitable for use in low power, portable connect the RESET output of the ADM6328 or ADM6348 to equipment. the RESET input of the microprocessor using a single pull-up RESET OUTPUT resistor to allow either device to initiate a system reset (see The ADM6326 and ADM6346 have an active low, push-pull Figure 8). reset output, whereas the ADM6328 and ADM6348 have an VCC active low, open-drain reset output, which requires an external pull-up resistor. The RESET signal is guaranteed to be valid for VCC RPULL-UP VCC V down to 1 V. MICROPROCESSOR CC ADM6328/ADM6348 SYSTEM When the ADM6326/ADM6328/ADM6346/ADM6348 are RESET powered up, the RESET output remains low for a period typically RESET INPUT GND GND eaqlluoawl st oa dtheeq uRaEtSeE tTim aec tfiover ttihme esoyustte pmer tiood p oofw 1e8r5 u mp sc. oTrhriesc ftelyat aunred 08052-008 Figure 8. Interfacing to a Microprocessor with a Bidirectional Reset Pin for the power supply to stabilize before any devices are brought out of reset and are allowed to begin executing instructions. Initializing TRANSIENT IMMUNITY a system in this way provides a more reliable startup for micro- To avoid unnecessary resets caused by fast power supply transients, processor systems. the ADM6326/ADM6328/ADM6346/ADM6348 provide glitch When the monitored voltage falls below its associated threshold immunity from negative-going V transients. CC (V ), RESET is asserted within 20 μs (typical). Asserting RESET TH Figure 5 shows the RESET comparator overdrive (that is, the this quickly means that the entire system can be reset at once maximum magnitude of negative-going pulses with respect to before any part of the system’s voltage falls below its recommended the typical threshold) vs. the pulse duration without a reset. operating voltage. This system reset can avoid dangerous and/or erroneous operation of a microprocessor based system. VCC VTH VTH VCC 1V 0V VCC RESET 0V tRP tRD 08052-009 Figure 9. RESET Timing Rev. B | Page 7 of 9

ADM6326/ADM6328/ADM6346/ADM6348 Data Sheet OUTLINE DIMENSIONS 3.04 2.90 2.80 1.40 1.30 1.20 3 2.64 2.10 1 2 0.60 1.03 0.45 0.89 2.05 1.02 1.78 0.95 0.54 REF 0.88 1.12 GAUGE 0.89 PLANE 0.100 0.180 0.013 0.085 0.51 SEPALTAINNGE 0.37 0.25 0.60 MAX 0.30 MIN COMPLIANTTO JEDEC STANDARDSTO-236-AB 011909-C Figure 10. 3-Lead Small Outline Transistor Package [SOT-23-3] (RT-3) Dimensions shown in millimeters Rev. B | Page 8 of 9

Data Sheet ADM6326/ADM6328/ADM6346/ADM6348 ORDERING GUIDE Typical Threshold RESET Output Marking Model1, 2 Voltage (T = 25°C) Structure Package Description Package Option Code A ADM6326-22ARTZ-R7 2.2 V Push-Pull 3-Lead SOT-23 RT-3 LAQ ADM6326-26ARTZ-R7 2.63 V Push-Pull 3-Lead SOT-23 RT-3 LAU ADM6326-27ARTZ-R7 2.7 V Push-Pull 3-Lead SOT-23 RT-3 LAV ADM6326-29ARTZ-R7 2.93 V Push-Pull 3-Lead SOT-23 RT-3 LAX ADM6326-30ARTZ-R7 3.0 V Push-Pull 3-Lead SOT-23 RT-3 LAY ADM6326-31ARTZ-R7 3.08 V Push-Pull 3-Lead SOT-23 RT-3 LAZ ADM6328-22ARTZ-R7 2.2 V Open-Drain 3-Lead SOT-23 RT-3 LB0 ADM6328-23ARTZ-R7 2.32 V Open-Drain 3-Lead SOT-23 RT-3 LB1 ADM6328-25ARTZ-R7 2.5 V Open-Drain 3-Lead SOT-23 RT-3 LB3 ADM6328-27ARTZ-R7 2.7 V Open-Drain 3-Lead SOT-23 RT-3 LB5 ADM6328-28ARTZ-R7 2.8 V Open-Drain 3-Lead SOT-23 RT-3 LB6 ADM6346-46ARTZ-R7 4.63 V Push-Pull 3-Lead SOT-23 RT-3 LCU ADM6348-33ARTZ-R7 3.3 V Open-Drain 3-Lead SOT-23 RT-3 LCV ADM6348-34ARTZ-R7 3.4 V Open-Drain 3-Lead SOT-23 RT-3 LCW ADM6348-35ARTZ-R7 3.5 V Open-Drain 3-Lead SOT-23 RT-3 LCX ADM6348-36ARTZ-R7 3.6 V Open-Drain 3-Lead SOT-23 RT-3 LCY ADM6348-37ARTZ-R7 3.7 V Open-Drain 3-Lead SOT-23 RT-3 LCZ ADM6348-38ARTZ-R7 3.8 V Open-Drain 3-Lead SOT-23 RT-3 LD0 ADM6348-39ARTZ-R7 3.9 V Open-Drain 3-Lead SOT-23 RT-3 LD1 ADM6348-40ARTZ-R7 4.0 V Open-Drain 3-Lead SOT-23 RT-3 LD2 ADM6348-41ARTZ-R7 4.1 V Open-Drain 3-Lead SOT-23 RT-3 LD3 ADM6348-42ARTZ-R7 4.2 V Open-Drain 3-Lead SOT-23 RT-3 LD4 ADM6348-43ARTZ-R7 4.3 V Open-Drain 3-Lead SOT-23 RT-3 LD5 ADM6348-44ARTZ-R7 4.38 V Open-Drain 3-Lead SOT-23 RT-3 LD6 ADM6348-45ARTZ-R7 4.5 V Open-Drain 3-Lead SOT-23 RT-3 LD7 ADM6348-46ARTZ-R7 4.63 V Open-Drain 3-Lead SOT-23 RT-3 LD8 1 The ADM6326/ADM6328/ADM6346/ADM6348 include many device options; however, not all options are released for sale. Released options are called standard models and are listed in the Ordering Guide. For the most up to date list of standard models, check the Single Supply Monitors IC page on the Analog Devices website. Contact sales for information on nonstandard models and be aware that samples and production units have very long lead times. 2 Z = RoHS Compliant Part. ©2009–2018 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08052-0-5/18(B) Rev. B | Page 9 of 9