LM3701

LM3700/LM3701 Microprocessor Supervisory Circuit with Low Line Output June 2002 LM3700/LM3701 Microprocessor Supervisory Circuit with Low Line Output General Description The LM3700/LM3701 series of microprocessor supervisory circuits provide the maximum flexibility for monitoring power supplies and battery controlled functions in systems without backup batteries. The LM3700/LM3701 series are available in a 9-bump micro SMD package. Built-in features include the following: Reset: Reset is asserted during power-up, power-down, and brownout conditions. RESET is guaranteed down to VCC of 1.0V. Low Line Output: This early power failure warning indicator goes low when the supply voltage drops to a value which is 2% higher than the reset threshold voltage. n n n n n n n No external components required RESET (LM3700) or RESET (LM3701) outputs Precision supply voltage monitor Factory programmable Reset Timeout Delay Available in micro SMD package for minimum footprint ± 0.5% Reset threshold accuracy at room temperature ± 2% Reset threshold accuracy over temperature extremes n Reset assertion down to 1V VCC (RESET option only) n 28 µA VCC supply current Applications n n n n Embedded Controllers and Processors Intelligent Instruments Automotive Systems Critical µP Power Monitoring Features n Standard Reset Threshold voltage: 3.08V n Custom Reset Threshold voltages: For other voltages between 2.2V and 5.0V in 10mV increments, contact National Semiconductor Corp. Typical Application 20011403 © 2002 National Semiconductor Corporation DS200114 www.national.com LM3700/LM3701 Connection Diagram Top View (looking from the coating side) micro SMD 9 Bump Package BPA09 20011401 Pin Descriptions Bump No. B1 C1 Name VCC RESET Power Supply input. Reset Logic Output. Pulses low for tRP (Reset Timeout Period) when triggered, and stays low whenever VCC is below the reset threshold or when MR is below VMRT. It remains low for tRP after either VCC rises above the reset threshold, or after MR input rises above VMRT (LM3700 only). Reset Logic Output. RESET is the inverse of RESET (LM3701 only). Low-Line Logic Output. Early Power-Fail warning output. Low when VCC falls below VLLOT (Low-Line Output Threshold). This output can be used to generate an NMI (Non-Maskable Interrupt) to provide an early warning of imminent power-failure. Ground reference for all signals. No Connect. No Connect. Test input used at factory only. Leave floating. Function RESET C3 LLO B3 A1, A2, A3, C2 B2 GND NC NC www.national.com 2 LM3700/LM3701 Block Diagram 20011405 3 www.national.com LM3700/LM3701 Ordering Information 20011404 *For other voltages between 2.2V and 5.0V, please contact National Semiconductor sales office. LM3700/LM3701 Part Number LM3700XCBP-308 LM3700XCBPX-308 LM3701XCBP-308 LM3701XCBPX-308 %% is the datecode and will vary with time. Output totem-pole totem-pole totem-pole totem-pole Reset Timeout Period 200ms 200ms 200ms 200ms Package Marking %%I0 %%I0 %%I1 %%I1 Table Of Functions Part Number LM3700 LM3701 * = available upon request. Contact National Active Low Reset x Active High Reset x Output (X = totem-pole) (Y = open-drain) X, Y* X Reset Timeout Period Customized Customized Low Line Output x x www.national.com 4 LM3700/LM3701 Absolute Maximum Ratings (Note 1) Power Dissipation (Note 3) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (VCC) All Other Inputs ESD Ratings (Note 2) Human Body Model Machine Model −0.3V to 6.0V −0.3V to VCC + 0.3V 1.5kV 150V Operating Ratings (Note 1) Temperature Range −40˚C ≤ TJ ≤ 85˚C LM3700/LM3701 Series Electrical Characteristics Limits in the standard typeface are for TJ = 25˚C and limits in boldface type apply over full operating range. Unless otherwise specified: VCC = +2.2V to 5.5V. Symbol VCC ICC Parameter Operating Voltage Range: VCC VCC Supply Current Reset Threshold LM3700 LM3701 All inputs = VCC; all outputs floating Conditions Min 1.0 1.2 28 Typ Max 5.5 5.5 50 Units POWER SUPPLY V µA RESET THRESHOLD VRST VCC falling VCC falling: TA = 0˚C to 70˚C VRSTH tRP Reset Threshold Hysteresis Reset Timeout Period Reset Reset Reset Reset Timeout Timeout Timeout Timeout Period Period Period Period = = = = A B C D 1 20 140 1120 −0.5 −2 −1.5 0.0032 • VRST 1.4 28 200 1600 20 2 40 280 2240 VRST +0.5 +2 +1.5 mV % ms tRD VCCto Reset Delay RESET VCC falling at 1mV/µs µs RESET (LM3701) VOL VCC > 2.25V, ISINK = 900µA VCC > 2.7V, ISINK = 1.2mA VCC > 4.5V, ISINK = 3.2mA VOH RESET VCC > 1.2V, ISOURCE = 50µA VCC > 1.8V, ISOURCE = 150µA VCC > 2.25V, ISOURCE = 300µA VCC > 2.7V, ISOURCE = 500µA VCC > 4.5V, ISOURCE = 800µA ILKG Output Leakage Current RESET VRESET = 5.5V 0.8 VCC 0.8 VCC 0.8 VCC 0.8 VCC VCC − 1.5V 1.0 µA V 0.3 0.3 0.4 V RESET (LM3700) VOL VCC > 1.0V, ISINK = 50µA VCC > 1.2V, ISINK = 100µA VCC > 2.25V, ISINK = 900µA VCC > 2.7V, ISINK = 1.2mA VCC > 4.5V, ISINK = 3.2mA VOH RESET VCC > 2.25V, ISOURCE = 300µA VCC > 2.7V, ISOURCE = 500µA VCC > 4.5V, ISOURCE = 800µA 0.8 VCC 0.8 VCC VCC − 1.5V 0.3 0.3 0.3 0.3 0.4 V 5 www.national.com LM3700/LM3701 LM3700/LM3701 Series Electrical Characteristics Symbol LLO VOL LLO Output Voltage VCC > 2.25V, ISINK = 900µA VCC > 2.7V, ISINK = 1.2mA VCC > 4.5V, ISINK = 3.2mA VOH VCC VCC VCC LLO OUTPUT VLLOT LLO Output Threshold (VLLO − VRST, VCC falling) Low-Line Comparator Hysteresis Low-Line Comparator Delay VCC falling at 1mV/µs Parameter Conditions (Continued) Limits in the standard typeface are for TJ = 25˚C and limits in boldface type apply over full operating range. Unless otherwise specified: VCC = +2.2V to 5.5V. Min Typ Max 0.3 0.3 0.4 0.8 VCC 0.8 VCC VCC − 1.5V 1.01 • VRST 1.02 • VRST 1.03 • VRST V V Units > 2.25V, ISOURCE = 300µA > 2.7V, ISOURCE = 500µA > 4.5V, ISOURCE = 800µA VLLOTH 0.0032 • VRST mV tCD 20 µs 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 do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed conditions. Note 2: The Human Body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. The machine model is a 200pF capacitor discharged directly into each pin. Note 3: The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(MAX), the junction-to-ambient thermal resistance, θJ-A, and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperture is calculated using: Where the value of θJ-A for the micro SMD package is 220˚C/W. www.national.com 6 LM3700/LM3701 Typical Performance Characteristics Supply Current vs Supply Voltage 3.3V Supply Current vs Temperature 20011411 20011415 Normalized Reset Threshold Voltage vs Temperature Reset Timeout Period vs VCC 20011412 20011432 Reset Timeout Period vs Temperature Max. Transient Duration vs Reset Comparator Overdrive (VCC = 3.3V) 20011410 20011416 7 www.national.com LM3700/LM3701 Typical Performance Characteristics Low-Line Comparator Propagation Delay vs Temperature (Continued) 20011414 Circuit Information Reset Output The Reset input of a µP initializes the device into a known state. The LM3700/LM3701 microprocessor supervisory circuits assert a forced reset output to prevent code execution errors during power-up, power-down, and brownout conditions. RESET is guaranteed valid for VCC > 1V. Once VCC exceeds the reset threshold, an internal timer maintains the output for the reset timeout period. After this interval, reset goes high. The LM3700 offers an active-low RESET; The LM3701 offers an active-high RESET. Any time VCC drops below the reset threshold (such as during a brownout), the reset activates. When VCC again rises above the reset threshold, the internal timer starts. Reset holds until VCC exceeds the reset threshold for longer than the reset timeout period. After this time, reset releases. Reset Threshold The LM3700/LM3701 family is available with a reset voltage of 3.08V. Other reset thresholds in the 2.20V to 5.0V range, in steps of 10 mV, are available; contact National Semiconductor for details. Low-Line Output (LLO) The low-line output comparator is typically used to provide a non-maskable interrupt to a µP when VCC begins falling. LLO monitors VCC and goes low when VCC falls below VLLOT (typically 1.02 • VRST) with hysteresis of 0.0032 • VRST. Special Precautions for the micro SMD Package As with most integrated circuits, the LM3700 and LM3701 are sensitive to exposure from visible and infrared (IR) light radiation. Unlike a plastic encapsulated IC, the micro SMD package has very limited shielding from light, and some sensitivity to light reflected from the surface of the PC board or long wavelength IR entering the die from the side may be experienced. This light could have an unpredictable affect on the electrical performance of the IC. Care should be taken to shield the device from direct exposure to bright visible or IR light during operation. Micro SMD Mounting The micro SMD package requires specific mounting techniques which are detailed in National Semiconductor Application Note AN-1112. Referring to the section Surface Mount Technology (SMT) Assembly Considerations, it should be noted that the pad style which must be used with the 9-pin package is the NSMD (non-solder mask defined) type. For best results during assembly, alignment ordinals on the PC board may be used to facilitate placement of the micro SMD device. www.national.com 8 LM3700/LM3701 Timing Diagrams 20011428 FIGURE 1. LM3700 Reset Time 20011429 FIGURE 2. LLO Output 9 www.national.com LM3700/LM3701 Typical Application Circuits 20011424 FIGURE 3. LM3701 Power-On Delay www.national.com 10 LM3700/LM3701 Typical Application Circuits (Continued) 20011422 FIGURE 4. Regulator/Switch with Long-Term Overvoltage Lockout Prevents Overdissipation in Linear Regulator 11 www.national.com LM3700/LM3701 Microprocessor Supervisory Circuit with Low Line Output Physical Dimensions unless otherwise noted inches (millimeters) NOTES: UNLESS OTHERWISE SPECIFIED 1. EPOXY COATING 2. 63Sn/37Pb EUTECTIC BUMP 3. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD. 4. PIN 1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION. REMAINING PINS ARE NUMBERED COUNTER CLOCKWISE. 5. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH, X2 IS PACKAGE LENGTH AND X3 IS PACKAGE HEIGHT. 6.NO JEDEC REGISTRATION AS OF AUG.1999. 9 bump micro SMD Package NS Package Number BPA09FFB The dimensions of X1, X2 and X3 are given below X1 = 1.412mm X2 = 1.412mm X3 = 0.850mm 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 Corporation Americas Email: support@nsc.com National Semiconductor Europe 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 Response Group Tel: 65-2544466 Fax: 65-2504466 Email: ap.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 www.national.com 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.