impala linear corporation october 1999 typical circuit impala linear corporation 1 (408) 730-3778 www.impalalinear.com ilc811/ilc812 microprocessor reset circuits general description the ilc811/ilc812 is a low cost microprocessor supervisory circuit that asserts a reset if the power supply drops below a designated threshold or the manual reset pin is forced low. several different reset thresholds are available to accommodate systems operating at 3 v, 3.3 v or 5 v. the ilc811 has an active low reset output, while the ilc812 offers an active high reset output. the reset output is guaranteed to remain asserted for a minimum of 140 ms after v cc has risen above the designated reset threshold. the ilc811/ilc812 is available in a 4-pin sot-143 package. features u precision voltage monitor for 3 v, 3.3 v or 5 v power supplies u 6 a supply current u 140 ms minimum reset pulse width u reset remains valid with v cc as low as 1.4v u active low manual reset input u no external components u 4-pin sot-143 package applications u critical microprocessor power monitoring u portable equipment u intelligent instruments u computers & printers u controllers pin - package configurations ilc811 v cc top view reset mr gnd 2 1 4 3 ilc812 reset mr gnd 2 1 4 3 v cc ilc811 ilc812 p v cc v cc reset reset input mr (reset) v cc ordering information place the device suffix of desired reset threshold voltage from the table below in the blank to complete the part number. part package temp. range ilc811_u 4-lead sot-143 -40c to +85c ilc812_u 4-lead sot-143 -40c to +85c reset threshold voltage (v) device suf?x 4.63 l 4.38 m 4.00 j 3.08 t 2.93 s 2.63 r
ilc811/ilc812 microprocessor reset circuits october 1999 impala linear corporation 2 (408) 730-3778 www.impalalinear.com absolute maximum ratings stresses above those listed under absolute maximum ratings may cause permanent device failure. functionality at or above these limits is not implied. exposure to absolute maximum ratings for extended periods may affect device reliability. operating ranges define those limits between which the functionality of the device is guaranteed. electrical characteristics v cc = 5v for ilc81_l/m/j, v cc = 3.3v for ilc81_s/t, v cc = 3v for ilc81_r, t a = operating temperature range, unless otherwise noted. parameter symbol ratings units terminal voltage v cc -0.3 to 6.0 v mr -0.3 to (v cc + 0.3) v input current v cc , mr 20 ma output current reset, reset 20 ma rate of rise v cc 100 v/s operating temperature range t a -40 to +85 c storage temperature range -65 to +150 c lead temperature (soldering - 10 sec.) 300 c power dissipation (t a = +70c) 320 mw parameter conditions min typ max units operating voltage range, v cc t a = 0c to 70c t a = -40c to 85c 1.4 1.6 5.5 5.5 v supply current, i cc ilc811l/m/j, ilc812l/m/j v cc < 3.6v, ilc811r/s/t, ilc812r/s/t 9 6 15 10 a reset voltage threshold, v th ilc811l, ilc812l ilc811m, ilc812m ilc811j, ilc812j ilc811t, ilc812t ilc811s, ilc812s ilc811r, ilc812r 4.50 4.25 3.89 3.00 2.85 2.55 4.63 4.38 4.00 3.08 2.93 2.63 4.75 4.50 4.10 3.15 3.00 2.70 v reset timeout period, t r 140 240 560 ms reset output voltage, v oh i source = 800 a, ilc811l/m/j v cc C 1.5 0.8 x v cc v i source = 500 a, ilc811r/s/t reset output voltage, v ol v cc = v th min., i sink = 3.2 ma, ilc811l/m/j v cc = v th min., i sink = 1.2 ma, ilc811r/s/t v cc > 1.4 v, i sink = 50 a, t a = 0c to 70c v cc > 1.6 v, i sink = 50 a, t a = -40c to 85c 0.4 0.3 0.3 0.3 v reset output voltage, v oh 1.8v < v cc < v th min., i source = 150 a 0.8 x v cc v reset output voltage, v ol i sink = 3.2ma, ilc812l/m/j i sink = 1.2ma, ilc812r/s/t 0.4 0.3 v mr minimum pulse width 10 s mr to reset delay 0.5 s mr input threshold, v ih v cc > v th max., ilc81_l/m/j ilc81_r/s/t 2.3 0.7 x v cc v mr input threshold, v il v cc > v th max., ilc81_l/m/j ilc81_r/s/t 0.8 0.25 x v cc v mr pull-up resistance 10 20 30 k w mr glitch immunity 100 ns
ilc811/ilc812 microprocessor reset circuits impala linear corporation 3 (408) 730-3778 www.impalalinear.com october 1999 pin functions circuit description microprocessor reset the reset pin is asserted whenever v cc falls below the reset threshold voltage or if mr (manual reset) is forced low. the reset pin remains asserted for a period of 240 ms after v cc has risen above the reset threshold voltage or mr has returned high. the reset function ensures the microprocessor is properly reset and powers up into a known condition after a power failure. reset will remain valid with v cc as low as 1.4v. v cc transients the ilc811/ilc812 are relatively immune to negative-going v cc glitches below the reset threshold. typically, a negative- going transient 125 mv below the reset threshold with a duration of 50 s (25 s for ilc81_r/s/t) or less will not cause an unwanted reset. interfacing to bidirectional reset pins the ilc811/ilc812 can interface with ps with bidirectional reset pins by connecting a 4.7 k w resistor in series with the ilc811/ilc812 output and the p reset pin. reset valid to 0v a resistor can be added from the reset pin to ground to ensure the reset output remains low with v cc down to 0v. a 100 k w resistor connected from reset to ground is recommended. the size of the resistor should be large enough to not load the reset output and small enough to pull-down any stray leakage currents. figure 3: reset valid to v cc = 0 v pin name pin number description ilc811 ilc812 gnd 1 1 ground pin. reset 2 n/a reset goes low if v cc falls below the reset threshold and remains asserted for one reset timeout period (140 ms min.) after v cc exceeds the reset threshold. reset n/a 2 reset goes high if v cc falls below the reset threshold and remains asserted for one reset timeout period (140ms min.) after v cc exceeds the reset threshold. mr 33 manual reset input. a logic low on mr forces a reset. the reset will remain asserted as long as mr is held low and for one reset timeout period (140 ms min.) after mr goes high. this input can be shorted to ground via a switch or driven from cmos or ttl logic. float if unused. v cc 4 4 power supply input, 3 v, 3.3 v or 5 v. v th v cc t r mr reset t r reset generator - + reset threshold (v) v cc mr reset reset gnd 4 3 2 1 (ilc811) (ilc812) ilc811 p 100k v cc v cc v cc reset reset
ilc811/ilc812 microprocessor reset circuits impala linear corporation 4 (408) 730-3778 www.impalalinear.com october 1999 alternate source cross reference guide device marking information industry p/n ilc direct replacement max811jeus-t ilc811ju max811leus-t ilc811lu max811meus-t ilc811mu max811reus-t ILC811RU max811seus-t ilc811su max811teus-t ilc811tu max812jeus-t ilc812ju max812leus-t ilc812lu max812meus-t ilc812mu max812reus-t ilc812ru max812seus-t ilc812su max812teus-t ilc812tu kjxx ilc811j klxx ilc811l kmxx ilc811m krxx ilc811r ksxx ilc811s ktxx ilc811t ljxx ilc812j llxx ilc812l lmxx ilc812m lrxx ilc812r lsxx ilc812s ltxx ilc812t xx = lot code
devices sold by impala linear corporation are covered by the warranty and patent indemnification provisions appearing in its terms of sale only. impala linear corporation makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. impala linear corporation makes no warranty of merchantability or fitness for any purpose. impala linear corporation reserves the right to discontinue production and change specifications and prices at any time and without notice. this product is intended for use in normal commercial applications. applications requiring an extended temperature range, unusual environmental requirements, or high reliability applications, such as military and aerospace, are specifically not recommended without additional processing by impala linear corporation. impala linear corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in an impala linear corporation product. no other circuits, patents, licenses are implied. life support policy impala linear corporations products are not authorized for use as critical components in life support devices or systems. 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 labelling, can be reasonably expected to result in a significant injury to the user. 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. ilc811/ilc812 microprocessor reset circuits impala linear corporation 5 (408) 730-3778 www.impalalinear.com october 1999 packaging information tape and reel information u package, 4-pin sot-143 small-outline transistor package 0.079 0.071 0.055 0.047 0.098 0.083 0.120 0.105 0.080 0.070 0.004 0.001 0.040 0.031 0.0059 0.0035 0.010 0.005 0-8 dimensions are in inches. 0.037 0.030 0.021 0.015 2.00.05 4.00.1 ?1.50.1 1.750.1 8.00.3 3.50.05 ?1.10.1 4.00.1 2.70.1 3.10.1 1.20.1 dimensions are in millimeters.
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