LM8364BALMFX45

LM8364 Micropower Undervoltage Sensing Circuits March 2003 LM8364 Micropower Undervoltage Sensing Circuits General Description The LM8364 series are micropower undervoltage sensing circuits that are ideal for use in battery powered microprocessor based systems, where extended battery life is a key requirement. A range of threshold voltages from 2.0V to 4.5V are available with an active low open drain output. These devices feature a very low quiescent current of 0.65µA typical. The LM8364 series features a highly accurate voltage reference, a comparator with precise thresholds and built-in hysterisis to prevent erratic reset operation, and guaranteed Reset operation down to 1.0V with extremely low standby current. These devices are available in the space saving SOT23 5-pin surface mount package. For other undervoltage thresholds and output options, please contact National Semiconductor. Features n Extremely Low Quiescent Current: 0.65µA, at VIN = 2.87V n High Accuracy Threshold Voltage ( ± 2.5%) n Open Drain Output n Input Voltage Range: 1V to 6V n Surface Mount Package (5-Pin SOT23) n Pin for pin compatible with MC33464 Applications n n n n Low Battery Detection Microprocessor reset Controller Power Fail Indicator Battery Backup Detection Functional Block Diagram Connection Diagram 5-Pin SOT23 20065906 Top View 20065907 © 2003 National Semiconductor Corporation DS200659 www.national.com LM8364 Pin Description 20065908 Ordering Information Package Part Number LM8364BALMF20 LM8364BALMFX20 5-Pin SOT23 LM8364BALMF30 LM8364BALMFX30 LM8364BALMF45 LM8364BALMFX45 Package Marking F01A F05A F04A Threshold Output Type Open Drain, Active Low Open Drain, Active Low Open Drain, Active Low Transport Media 1k Units Tape and Reel 3k Units Tape and Reel 1k Units Tape and Reel 3k Units Tape and Reel 1k Units Tape and Reel 3k Units Tape and Reel MF05A NSC Drawing 2.0V 3.0V 4.5V www.national.com 2 LM8364 Absolute Maximum Ratings (Note 1) Junction Temperature 125˚ If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage RESET Output Voltage RESET Output Current Storage Temperature Range Mounting Temp. Lead temp (Soldering, 10 sec) 260˚C −0.3V to 6.5V −0.3V to 6.5V 70mA −65˚C to 150˚C Operating Ratings (Note 1) Temperature Range Thermal Resistance to ambient (θJA) ESD Tolerance Human Body Model Machine Model 2000V 200V −40˚C to 85˚C 265˚C/W Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA = 25˚C. Symbol VDET− Parameter Detector Threshold Voltage Conditions High to Low State Output (VIN Decreasing) 20 Suffix 30 Suffix 45 Suffix VHYS Detector Threshold Hysteresis VIN Increasing 20 Suffix 30 Suffix 45 Suffix ∆Vdet/∆T VOL IOL VIN IIN Detector Threshold Voltage Temperature Coefficient RESET Output Voltage Low State RESET Output Sink Current Operating Input Voltage Range Quiescent Input Current 20 Suffix VIN = 1.9V VIN = 4.0V 30 Suffix VIN = 2.87V VIN = 5.0V 45 Suffix VIN = 4.34V VIN = 6.0 tp Propagation Delay Time Figure 1 0.70 0.85 60 1.0 1.4 300 µs 0.65 0.77 0.9 1.3 µA 0.55 0.70 0.8 1.3 (Open Drain Output: ISINK = 1mA) VIN = 1.5V, VOL = 0.5V 1.0 1.0 0.060 0.090 0.135 0.100 0.150 0.225 0.140 0.210 0.315 PPM/˚C 0.5 V mA 6.0 V V 1.950 2.925 4.388 2.0 3.0 4.5 2.050 3.075 4.613 V Min (Note 3) Typ (Note 2) Max (Note 3) Units ± 100 0.25 2.5 Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics. Note 2: Typical values represent the most likely parametric norm Note 3: All limits are guaranteed by testing or statistical analysis. 3 www.national.com LM8364 Typical Performance Characteristics Input Current vs. Input Voltage LM8364BALMF45 Reset Output Voltage vs. Input Voltage LM8364BALMF45 20065901 20065902 Reset Output Sink Current vs. Input Voltage LM8364BALMF45 Reset Output Sink Current vs. Output Voltage LM8364BALMF45 20065903 20065904 Detector Threshold Voltage vs. Temperature LM8364BALMF45 20065905 www.national.com 4 LM8364 Application Notes The propagation delay time for the LM8364 is measured using a 470kΩ pull-up resistor connected to from the RESET output pin to 5V in addition to a 10pF capacitive load con- nected from the same pin to GND. Figure 1 shows the timing diagram for the measurement for the propagation delay. VDET+ is equal to the sum of the detector threshold, VDET−, and the built in hysteresis, VHYS. 20065909 FIGURE 1. Propagation Delay Timing Diagrams The LM8364 ultra-low current voltage detector was designed to monitor voltages and to provide an indication when the monitored voltage, VIN, dropped below a precisely trimmed threshold voltage. This characteristic is displayed in the typical operating timing diagram below. VIN is the voltage that is being monitored and a pull up resistor is connected from the RESET output pin to VIN. VIN is at some value above VDET+ and then begins to decrease. Since this is an Active Low device the RESET output is pulled High through the pull-up resistor and tracks VIN until VIN crosses the trimmed threshold VDET−. At this point the LM8364 recognizes that VIN is now in a fault condition and the output immediately changes to the Logic Low State. The RESET output will remain in this low state until VIN increases above the threshold VDET− + VHYS. This point is also known as VDET+ as indicated earlier. This built-in hysteresis has been added to the design to help prevent erratic reset operation when the input voltage crosses the threshold. The LM8364 has a wide variety of applications that can take advantage of its precision and low current consumption to monitor Input voltages even though it was designed as a reset controller in portable microprocessor based systems. It is a very cost effective and space saving device that will protect your more expensive investments of microprocessors and other devices that need a guaranteed supply voltage for proper operation. 20065910 FIGURE 2. Timing Waveforms 5 www.national.com LM8364 Typical Applications 20065911 Microprocessor Reset Circuit 20065912 Dual Power Supply Undervoltage Supervision www.national.com 6 LM8364 Typical Applications (Continued) 20065913 Microcontroller System Load Sensing 20065914 LED Bar Graph Voltage Monitor 7 www.national.com LM8364 Micropower Undervoltage Sensing Circuits Physical Dimensions unless otherwise noted inches (millimeters) 5-Pin SOT23 NSC Package Number MF05A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Americas Customer Support Center Email: new.feedback@nsc.com Tel: 1-800-272-9959 www.national.com National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Support Center Fax: +65-6250 4466 Email: ap.support@nsc.com Tel: +65-6254 4466 National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: jpn.feedback@nsc.com Tel: 81-3-5639-7560 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.