LM8365 Micropower Undervoltage Sensing Circuits with Programmable Output Delay General Description Features The LM8365 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 or CMOS, output. These devices feature a very low quiescent current of 0.65µA typical. The LM8365 series features a highly accurate voltage reference, a comparator with precise thresholds and built-in hysterisis to prevent erratic reset operation, a time delayed output which can be programmed by the system designer, and guaranteed Reset operation down to 1.0V with extremely low standby current. These devices are available in the space saving 5-Pin SOT23 surface mount package. For additional undervoltage thresholds and output options, please contact National Semiconductor. n Extremely Low Quiescent Current: 0.65µA, at VIN = 2.87V n High Accuracy Threshold Voltage ( ± 2.5%) n Complementary or Open Drain Output n Programmable output delay by external Capacitor (100ms typ with 0.1µF) n Input Voltage Range: 1V to 6V n Surface Mount Package (5-Pin SOT23) n Pin for pin compatible with MC33465 Applications n n n n Low Battery Detection Microprocessor Reset Controller Power Fail Indicator Battery Backup Detection Functional Diagrams CMOS Output Open Drain Output 20066013 20066014 Connection Diagram 5-Pin SOT23 20066012 Top View © 2003 National Semiconductor Corporation DS200660 www.national.com LM8365 Micropower Undervoltage Sensing Circuits with Programmable Output Delay March 2003 LM8365 Pin Description 20066015 Ordering Information Package Part Number LM8365BALMF22 LM8365BALMFX22 LM8365BALMF27 5-Pin SOT23 LM8365BALMFX27 LM8365BCLMF30 LM8365BCLMFX30 LM8365BALMF45 LM8365BALMFX45 www.national.com Package Marking Threshold Output Type Transport Media F08A 2.2V Open Drain, Active Low 3k Units Tape and Reel F07A 2.7V Open Drain, Active Low F02A 3.0V CMOS, Active Low 3k Units Tape and Reel F06A 4.5V Open Drain, Active Low 3k Units Tape and Reel 2 NSC Drawing 1k Units Tape and Reel 1k Units Tape and Reel 3k Units Tape and Reel 1k Units Tape and Reel 1k Units Tape and Reel MF05A Junction Temperature (Note 1) 125˚C If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Operating Ratings (Note 1) Supply Voltage −0.3V to 6.5V Temperature Range −0.3V to 6.5V Thermal Resistance to Ambient (θJA) RESET Output Voltage RESET Output Current Storage Temperature Range −40˚C to 85˚C 265˚C/W ESD Tolerance 70mA Human Body Model −65˚C to 150˚C 2000V Machine Model Mounting Temperature Lead Temp. (Soldering 10 sec) 200V 260˚C Electrical Characteristics Unless otherwise specified, all limits guaranteed for TA = 25˚C. Symbol Parameter Conditions Min (Note 3) Typ (Note 2) Max (Note 3) 22 Suffix 2.145 2.2 2.255 27 Suffix 2.633 2.7 2.767 30 Suffix 2.925 3.0 3.075 45 Suffix 4.388 4.5 4.613 22 Suffix 0.066 0.110 0.154 27 Suffix 0.081 0.135 0.189 30 Suffix 0.090 0.150 0.210 45 Suffix 0.135 0.225 0.315 Units High to Low State Output (VIN Decreasing) VDET− Detector Threshold Voltage V VIN Increasing VHYS Detector Threshold Hysteresis ∆Vdet/∆T Detector Threshold Voltage Temperature Coefficient VOH VOL RESET Output Voltage IOL RESET Output Sink Current IOH ICD RD Delay Resistance VIN Operating Input Voltage Range ± 100 (CMOS Output: ISOURCE = 1mA) (Open Drain or CMOS Output: ISINK = 1mA) VIN-2.1 VIN-1.0 0.25 V PPM/˚C VIN 0.5 V VIN = 1.5V, VOL = 0.5V 1.0 2.5 mA RESET Output Source Current VIN = 4.5V, VOL = 2.4V 1.0 7.0 mA Delay Pin Output Sink Current VIN = 1.5V, VCD = 0.5V 0.2 1.8 0.5 1.0 1.0 mA 2.0 MΩ 6.0 V 22 Suffix VIN = 2.10V 0.57 0.8 VIN = 4.20V 0.71 1.3 VIN = 2.60V 0.62 0.9 VIN = 4.70V 0.75 1.3 VIN = 2.87V 0.65 0.9 VIN = 5.00V 0.77 1.3 VIN = 4.34V 0.70 1.0 VIN = 6.00V 0.85 1.4 27 Suffix IIN Quiescent Input Current 30 Suffix µA 45 Suffix 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 LM8365 Absolute Maximum Ratings LM8365 Typical Performance Characteristics Input Current vs. Input Voltage LM8365BALMF45 Reset Output Voltage vs. Input Voltage LM8365BALMF45 20066001 20066002 Reset Output Source Current vs. Input Voltage LM8365BCLMF30 Reset Output Sink Current vs. Input Voltage LM8365BALMF27 20066003 20066004 CD Sink Current vs. Input Voltage LM8365BALMF27 Reset Output Sink Current vs. Reset Output Voltage LM8365BALMF45 20066005 www.national.com 20066006 4 (Continued) CD Delay Pin Threshold Voltage vs. Temperature LM8365BALMF27 CD Sink Current vs. CD Voltage 20066008 20066007 Detector Threshold Voltage vs. Temperature LM8365BALMF45 Delay Resistance vs. Temperature 20066010 20066009 Output Time Delay vs. Capacitance 20066011 5 www.national.com LM8365 Typical Performance Characteristics LM8365 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. tD1 is the propagation time from High-to-Low and tD2 is the propagation from Low-to-High. Application Notes The propagation delay time for the LM8365 is measured using a 470kΩ pull-up resistor connected to from the RESET output pin to 5V in addition to a 10pF capacitive load connected from the same pin to GND. Figure 1 shows the timing 20066016 FIGURE 1. Propagation Delay Timing Diagrams through an internal pull-up resistor RD. Once the capacitor has charged up past the internal Delay Pin Threshold, which is typically 0.675 VIN, the RESET output will revert back to it’s original state. The LM8365 has built-in hysteresis to help prevent erratic reset operation when the input voltage crosses the threshold. The LM8365 has a wide variety of applications that can take advantage of it’s 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 and time delay for proper operation. The LM8365 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. The voltage detector of the LM8365 drives a time delay generator that may be programmed for fixed lengths of time depending on the application needs. This characteristic is displayed in the typical operating timing diagram in Figure 2. VIN is the voltage that is being monitored and as it decreases passed the precisely trimmed threshold VDET− the Active Low RESET output drops to a Logic Low state and the CD pin drops to 0V. During this state the external capacitor connected to the CD pin is immediately discharged by an internal N-Channel MOSFET. When VIN increases above the threshold VDET+ (VDET− + VHYS) the capacitor connected to the CD pin starts to charge up to VIN www.national.com 6 LM8365 Application Notes (Continued) 20066017 FIGURE 2. Timing Waveforms 7 www.national.com LM8365 Typical Applications 20066018 Microprocessor Reset Circuit 20066019 Battery Charge Indicator Using LM8365BCLMF30 20066020 Missing Pulse Detector or Frequency Detector Using LM8365BALMF45 www.national.com 8 inches (millimeters) 5-Pin SOT23-5 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: [email protected] Tel: 1-800-272-9959 www.national.com National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530 85 86 Email: [email protected] 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: [email protected] Tel: +65-6254 4466 National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: [email protected] 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. LM8365 Micropower Undervoltage Sensing Circuits with Programmable Output Delay Physical Dimensions unless otherwise noted