package order information t a (c) plastic soic 8-pin 0 to 70 lx7001cdm LX7001CLP ? -40 to 85 lx7001idm lx7001ilp ? -55 to 125 ? ? lx7001my dm plastic to-92 3-pin lp ceramic dip 8-pin y note: all surface-mount packages are available in tape & reel. append the letter "t" to part number. (i.e. lx7001cdmt) t ransient i mmune u ndervoltage s ensing c ircuit p roduction d ata s heet t he i nfinite p ower of i nnovation lx7001 description the lx7001 is an improved undervoltage sensing circuit specifi- cally designed for use as a reset controller in microprocessor-based systems. today's complex miniaturized systems present difficult challanges to the system designer such as overcom- ing spurious noise problems. the lx7001 is optimized for systems that must be tolerant of high-speed power supply glitches caused by high-speed logic transitions and similar switching phenomena. the lx7001 offers a unique stage that couples glitch immunity with a micropower, ultra- stable band-gap reference for preci- sion sensing of undervoltage condi- tions. it offers the designer an key features fully characterized, transient immune input stage (see product highlight) monitors 5v supplies (v trip =4.6v typ.) outputs fully defined at v cc =1v ultra-low supply current (500a max. over temp) ! temperature compensated i cc for extremely stable current consumption ! p reset function programmable with 1 external resistor and capacitor ! comparator hysteresis prevents output oscillation ! electrically compatible with motorola mc34064 ! pin-to-pin compatible with motorola mc34064/mc34164 economical, space-efficient solution for low supply voltage detection when used in combination with a single pull-up resistor. adding one capacitor offers the functionality of a programmable delay time after power returns. additionally, the lx7001 offers excellent temperature stability. a high-quality trimmed voltage reference and bias circuit permit very accurate and repeatable undervoltage sensing. the remaining blocks consist of a comparator with hyster- esis, high current clamping diode and open collector output stage capable of sinking up to 60ma. the lx7001's reset output is specified to be fully functional at v in =1v. applications all microprocessor or microcontroller designs using 5v supplies simple 5v undervoltage detection product highlight i nput t ransient i mmunity 100 0 0.1 100 1 10 100 (t n ) noise pulse width - (s) immune active (e n ) noise pulse amplitude - (mv) note: for current data & package dimensions, visit our web site: http://www.linfinity.com. copyright ? 1999 rev. 1.3 8/02 1 11861 w estern a venue , g arden g rove , ca. 92841, 714-898-8121, f ax : 714-893-2570 l in f inity m icroelectronics i nc .
t ransient i mmune u ndervoltage s ensing c ircuit lx7001 product databook 1996/1997 copyright ? 1999 rev. 1.3 8/02 2 p roduction d ata s heet absolute maximum ratings (note 1) input supply voltage (v in ) ............................................................................... -1v to 12v reset output voltage (v out ) .......................................................................... -1v to 12v output sink current (i ol ) ............................................................ internally limited (ma) clamp diode forward current (i f ), pin 1 to pin 2 ............................................... 100ma operating junction temperature ceramic (y - package) .......................................................................................... 150c plastic (dm, lp - packages) .................................................................................. 150c storage temperature range ...................................................................... -65c to 150c lead temperature (soldering, 10 seconds) ............................................................. 300c package pin outs reset v in n.c. ground n.c. n.c. n.c. n.c. 1 8 2 7 3 6 4 5 dm package (top view) dm package: thermal resistance-junction to ambient,
t ransient i mmune u ndervoltage s ensing c ircuit lx7001 product databook 1996/1997 3 copyright ? 1999 rev. 1.3 8/02 p roduction d ata s heet input supply voltage v in reset output voltage v out clamp diode forward current i f operating ambient temperature range: lx7001c lx7001i lx7001m recommended operating conditions (note 2) parameter symbol units recommended operating conditions min. typ. max. 110v 10 v 50ma 070c -40 85 c -55 125 c note 2. range over which the device is functional. electrical characteristics (unless otherwise specified, these specifications apply over the operating ambient temperatures of 0c t a 70c for the lx7001c, -40c t a 85c for the lx7001i, and -55c t a 125c for the lx7001m. low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature.) 4.5 4.62 4.7 v 4.5 4.60 4.7 v 0.01 0.02 0.05 v comparator section threshold voltage high state output v t+ v in increasing ? 4v to 5v low state output v t- v in decreasing ? 5v to 4v hysteresis v h output sink saturation voltage v in = 4.0v, i ol = 8.0ma v ol v in = 4.0v, i ol = 2.0ma v in = 1.0v, i ol = 0.1ma output sink current i ol v out = 4.0v output off-state leakage i oh v out = 5.0v v out = 10v clamp diode forward voltage v f pin 1 to pin 2, i f = 10ma reset output section total device supply current i cc v in = 5.0v parameter symbol test conditions units lx7001c/7001i/7001m min. typ. max. 0.06 1.0 v 0.25 0.4 v 0.3 0.1 v 10 40 60 ma 0.01 0.5 a 0.02 2.0 a 0.6 0.82 1.2 v 345 500 a
t ransient i mmune u ndervoltage s ensing c ircuit lx7001 product databook 1996/1997 copyright ? 1999 rev. 1.3 8/02 4 p roduction d ata s heet block diagram graph / curve index figure index characteristic curves figure # 1. reset output voltage vs. input voltage 2. power-up reset voltage 3. reset output voltage vs. input voltage 4. threshold voltage vs. temperature 5. threshold hysteresis vs. temperature 6. supply current vs. input voltage 7. supply current vs. temperature 8. low level output current vs. temperature 9. low level output voltage vs. low level output current 10. voltage vs. clamp diode forward current 11. propagation delay 12. low level output voltage vs. temperature application circuits figure # 13. low voltage microprocessor reset 14. switching the load off when battery reaches below 4.3v 15. voltage monitor 16. mosfet low voltage gate drive protection 17. low voltage microprocessor reset with additional hysteresis 1.2 v ref v in reset ground
t ransient i mmune u ndervoltage s ensing c ircuit lx7001 product databook 1996/1997 5 copyright ? 1999 rev. 1.3 8/02 p roduction d ata s heet characteristic curves figure 2. ? power-up reset voltage 04 10 0 4 (v in ) input voltage - (v) 10 (v out ) reset output voltage - (v) 2 6 8 268 r l = 10k t a = 25 c figure 3. ? reset output voltage vs. input voltage 4.55 0 2 (v in ) input voltage - (v) 5 (v out ) reset output voltage - (v) 1 3 4 4.57 4.56 4.58 4.59 4.60 4.61 4.62 4.63 4.64 4.65 -55 4.54 4.58 (t j ) temperature - ( c) 4.64 (v t ) threshold voltage - (v) 4.56 4.60 4.62 -25 0 25 50 75 100 125 150 upper threshold high state output lower threshold low state output v t+ v t- figure 4. ? threshold voltage vs. temperature 0 200 500 0 0.8 (t) time - ( s) 2.0 power-up reset voltage - (v) 0.4 1.2 1.6 100 300 400 0.2 0.6 1.0 1.4 1.8 reset v in figure 1. ? reset output voltage vs. input voltage
t ransient i mmune u ndervoltage s ensing c ircuit lx7001 product databook 1996/1997 copyright ? 1999 rev. 1.3 8/02 6 p roduction d ata s heet characteristic curves -55 -25 0 25 50 75 100 125 150 10 18 (t j ) temperature - ( c) 30 (v h ) hysteresis voltage - (mv) 14 22 26 reset load = 10k 04 10 0 400 (v in ) input voltage - (v) 1000 (i cc ) supply current - ( a) 200 600 800 268 -40 c +25 c +85 c +125 c -55 c 0 400 (t j ) temperature - ( c) 1200 (i cc ) supply current - ( a) 200 600 800 1000 100 300 500 700 900 1100 1300 -55 -25 0 25 50 75 100 125 150 10v 5v figure 8. ? low level output current vs. temperature figure 7. ? supply current vs. temperature figure 5. ? threshold hysteresis vs. temperature figure 6. ? supply current vs. input voltage 0 30 (t j ) temperature - ( c) 80 (i ol ) low level output current - (ma) 20 40 50 10 60 70 -55 -25 0 25 50 75 100 125 150
t ransient i mmune u ndervoltage s ensing c ircuit lx7001 product databook 1996/1997 7 copyright ? 1999 rev. 1.3 8/02 p roduction d ata s heet characteristic curves figure 10. ? voltage vs. clamp diode forward current 0 0 1000 (i sink ) low level output current - (ma) (v ol ) low level output voltage - (mv) 500 1500 2000 10 20 30 40 v in = 4v -55 c 125 c 25 c 040 100 0.5 0.8 (i f ) forward current - (ma) 1.2 (v f ) forward voltage - (v) 0.7 0.9 1 20 60 80 reset = 0v 10 30 50 70 90 1.1 0.6 -55 c -40 c 125 c 85 c 25 c 06 16 0 6.0 (t) time - ( s) 5.5 v in - (v) 4.0 4.0 4.5 210 t a = 25 c 4 8 12 14 5.0 2.0 reset - (v) ref 10k reset 5v 4v v in -55 -25 0 25 50 75 100 125 150 0 30 (t j ) temperature - ( c) 80 (v ol ) low level output voltag e - (mv) 20 40 50 10 60 70 v in = 1v i sink = 100 a figure 12. ? low level output voltage vs. temperature figure 11. ? propagation delay figure 9. ? low level output voltage vs. low level output current
t ransient i mmune u ndervoltage s ensing c ircuit lx7001 product databook 1996/1997 copyright ? 1999 rev. 1.3 8/02 8 p roduction d ata s heet typical application circuits figure 13. ? low voltage microprocessor reset. a time delayed reset can be accomplished with the addition of c dly . for systems with extremely fast power supply rise times (< 500ns) it is recommended that the rc dly time constant be greater than 5.0s. v th(mpu) is the microprocessor reset input threshold. overheating of the logic level power mosfet due to insufficient gate voltage can be prevented with the above circuit. when the input signal is below the 4.3 volt threshold of the lx7001c, its output grounds the gate of the l 2 mosfet. figure 15. ? voltage monitor. figure 16. ? mosfet low voltage gate drive protection. v th(mpu) v in 1 - t dly = r c dly in 1 figure 14. ? switching the load off when battery reaches below 4.3v. power supply 1.2 v ref microprocessor circuit reset c dly r v in 1.2 v ref load reset v in power supply 1.2 v ref reset v in 1.0k 1.2 v ref reset v in 270 4.3v v cc r l smp60n03-10 l
t ransient i mmune u ndervoltage s ensing c ircuit lx7001 product databook 1996/1997 9 copyright ? 1999 rev. 1.3 8/02 p roduction d ata s heet typical application circuits (con't.) figure 17. ? low voltage microprocessor reset with additional hysteresis. comparator hysteresis can be increased with the addition of resistor r h . the hysteresis equation has been simplified and does not account for the change of input current i in as v cc crosses the comparator threshold. an increase of the lower threshold ? ? ? ? v h = + 0.02 ? v th (lower) = 340 r h x 10 -6 where: r h 150 ? r l 1.5 ? 10k ? 4.6 r h r l test data v h ? v th r h r l (mv) (mv) ( ? )( ? ) 20000 51 3.4 10 1.5 40 6.8 20 4.7 81 6.8 20 1.5 71 10 30 2.7 112 10 30 1.5 100 16 47 2.7 164 16 47 1.5 190 34 100 2.7 327 34 100 1.5 276 51 150 2.7 480 51 150 1.5 1.2 v ref microprocessor circuit reset v in power supply r l r h i in production data - information contained in this document is proprietary to linfinity, and is current as of publication date. t his document may not be modified in any way without the express written consent of linfinity. product processing does not necessarily inclu de testing of all parameters. linfinity reserves the right to change the configuration and performance of the product and to discontinue pro duct at any time.
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