general description the max6467/max6468 microprocessor (p) supervisory circuits monitor single power-supply voltages from +1.8v to +5.0v and assert a reset if the supply voltage drops below its preset threshold. an edge-triggered, one-shot manual reset function ensures that the p enters the reset mode for a fixed timeout period only, even in the event of a continuously asserted manual reset. the max6467/ max6468 significantly improve system reliability compared to traditional manual reset supervisory circuits. a variety of factory-trimmed threshold options accommodate different supply voltages and tolerances, eliminating external components. the factory-set thresholds range from +1.575v to +4.625v to monitor +5.0v, +3.3v, +3.0v, +2.5v, and +1.8v supplies with various tolerances. reset timeout periods of 150ms (min) and 1200ms (min) are available to accommodate different p platforms. a single, active-low reset output asserts when v cc drops below its threshold or if the edge-triggered mr asserts low. reset remains low for the reset time - out period after v cc rises above its threshold and for a fixed, one-shot timeout period after a manual reset input falling edge. reset remains valid as long as v cc remains above +1v. open-drain (max6467) and push- pull (max6468) output options provide additional flexibility in the system design. the max6467/max6468 are offered in the space-saving 4-pin sot143 package and the ultra-small 4-pin sc70 package and are specified over the automotive (-40c to +125c) temperature range. applications cell phones/pdas embedded control systems industrial equipment automotive products portable/battery-powered equipment medical devices dsl modems mp3 players gps systems digital cameras features precision factory-set reset threshold voltages for +5.0v, +3.3v, +3.0v, +2.5v, and +1.8v supplies edge-triggered manual reset input with one-shot pulsed reset output two reset timeout period options (150ms or 1200ms min) immune to short voltage transients low supply current (3 a at v cc = +1.8v) reset valid to v cc = +1v active-low open-drain and push-pull reset output options -40 c to +125 c operating temperature range small 4-pin sc70 and sot143 packages no external components required pin compatible with max811, max6315, max6384, and max6386 ordering information appears at end of data sheet. max6467max6468 +1.0v to +5.5v v cc gnd v cc gnd mr reset resetinput p typical operating circuit max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset 19-2523; rev 5; 10/15 downloaded from: http:///
v cc to gnd ......................................................... -0.3v to +6.0v reset to gnd open-drain ....................................................... -0.3v to +6.0v push-pull .............................................. -0.3v to (v cc + 0.3v) mr to gnd ............................................... -0.3v to (v cc + 0.3v) input/output current (all pins) ............................................ 20ma continuous power dissipation (t a = +70c) 4-pin sc70 (derate 3.1mw/c above +70c) ............. 245mw 4-pin sot143 (derate 4mw/c above +70vc) ........... 320mw operating temperature range ......................... -40c to +125c storage temperature range ............................ -65c to +150c junction temperature ...................................................... +150c lead temperature (soldering, 10s) ................................. +300c (v cc = +1.2v to +5.5v, t a = -40c to +125c, unless otherwise noted. typical values are at t a = +25c.) (note 1) parameter symbol conditions min typ max units operating voltage range v cc t a = 0c to +125c 1.0 5.5 v t a = -40c to 0c 1.2 5.5 supply current i cc v cc = +5.5v, no load 7 13 a v cc = +3.6v, no load 6 11 v cc = +2.5v, no load 4 8 v cc = +1.8v, no load 3 7.5 v cc reset threshold (see the reset threshold table) v th t a = +25c -1.5% v th +1.5% v t a = -40c to +85c -2.5% +2.5% t a = +85c to +125c -3% +3% v cc reset delay t rd v cc falling at 10mv/s from v th + 100mv to v th - 100mv 35 s v cc reset timeout period t rp d3 option 150 225 300 ms d7 option 1200 1800 2400 mr timeout period t mrp d3 and d7 options 150 225 300 ms mr rising debounce period (note 2) t deb d3 and d7 options 150 225 300 ms mr input voltage v il v th < +4v 0.3 x v cc v v ih 0.7 x v cc v il v th +4v 0.8 v ih 2.4 mr minimum input pulse 1 s mr glitch rejection 100 ns mr to reset delay 200 ns mr pullup resistance mr to v cc 500 1560 3000 ? reset output high (max6468 only) v oh v cc +2.5v, i source = 500a, reset not asserted 0.8 x v cc v v cc +4.5v, i source = 800a, reset not asserted 0.8 x v cc max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset www.maximintegrated.com maxim integrated 2 electrical characteristics stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. absolute maximum ratings downloaded from: http:///
(v cc = +5v, max6468us29d3 device, t a = +25c, unless otherwise noted.) note 1: specifications over temperature are guaranteed by design. production testing at t a = +25c only. note 2: the mr input ignores falling edges that occur within the mr rising debounce period (t deb ) after mr first rises from low to high (after a valid mr reset assertion). this prevents invalid reset assertion due to switch bounce. (v cc = +1.2v to +5.5v, t a = -40c to +125c, unless otherwise noted. typical values are at t a = +25c.) (note 1) parameter symbol conditions min typ max units reset output low v ol v cc +1v, i sink = 80a, reset asserted 0.3 v v cc +2.5v, i sink = 1.2ma, reset asserted 0.3 v cc +4.5v, i sink = 3.2ma, reset asserted 0.3 reset output leakage current (max6467 only) i lkg reset not asserted 1 a output voltage low vs. sink current max6467 toc06 i sink (ma) v ol (mv) 9 8 6 7 2 3 4 5 1 50 100 150 200 250 300 350 400 450 500 550 600 0 0 10 v cc = 5.0v normalized reset threshold vs. temperature max6467 toc05 temperature (c) normalized reset threshold (v) 110 95 80 65 50 35 20 5 -10 -25 0.995 1.000 1.005 1.0100.990 -40 125 reset timeout period vs. temperature max6467 toc04 temperature (c) reset timeout period (ms) 110 95 65 80 -10 5 20 35 50 -25 201 202 203 204 205 206 207 208 209 210200 -40 125 v cc to reset delay vs. temperature max6467 toc03 temperature (c) v cc to reset delay ( s) 110 95 80 65 50 35 20 5 -10 -25 18 20 22 24 2616 -40 125 v cc = v th + 100mv to v th - 100mv supply current vs. supply voltage max6467 toc02 supply voltage (v) supply current ( a) 5.0 4.5 3.5 4.0 1.0 1.5 2.0 2.5 3.0 0.5 1 2 3 4 5 6 7 8 9 10 0 0 5.5 supply current vs. temperature max6467 toc01 temperature (c) supply current ( a) 110 95 65 80 -10 5 20 35 50 -25 1 2 3 4 5 6 7 8 9 10 0 -40 125 v cc = +5.5v v cc = +3.6v v cc = +1.8v v cc = +2.5v max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset www.maximintegrated.com maxim integrated 3 typical operating characteristics electrical characteristics downloaded from: http:///
(v cc = +5v, max6468us29d3 device, t a = +25c, unless otherwise noted.) reset timeout period max6467 toc12 40ms/div 3.3v3.3v 0 0 v cc 2v/div reset 2v/div reset pullup and pulldown response max6467 toc11 40 s/div 1.675v1.6v 0 1.475v v cc 200mv/div reset 500mv/div c reset = 47pf, r pullup = 100k ? , v pullup = 1.6v max6467_s16d3-t propagation delay (with 100mv overdrive) max6467 toc10 4 s/div 3.0v3v 0 2.8v v cc 100mv/div ac-coupledreset 1v/div max6467 toc09 temperature (c) 110 95 65 80 -10 5 20 35 50 -25 65 70 75 80 85 90 95 100 105 110 115 120 60 -40 125 mr to reset delay vs. temperature mr to reset delay (ns) maximum transient duration vs. reset threshold overdrive max6467 toc08 reset threshold overdrive (mv) maximum transient duration ( s) 50 40 30 20 10 100 200 300 400 500 600 0 0 60 reset asserts above this line output voltage high vs. source current max6467 toc07 i source (ma) v oh (v) 7 6 4 5 2 3 1 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 0 0 8 v cc = +5.0v max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset maxim integrated 4 www.maximintegrated.com typical operating characteristics downloaded from: http:///
pin name function 1 gnd ground 2 reset reset output. reset is an active-low open-drain (max6467) or push-pull (max6468) output. reset asserts low when v cc drops below the selected threshold and remains low for the v cc reset timeout period after v cc rises above the threshold. the reset one-shot asserts low for a ixed mr reset timeout period on the falling edge of the manual reset input. the open-drain output requires an external pullup resistor 3 mr manual reset input. drive mr low to initiate a reset output. mr controls an edge-triggered one-shot that asserts reset low for a ixed mr timeout period when mr is driven low. internal timing circuitry ignores switch close and open bounce to ensure proper one-shot reset timing 4 v cc power-supply input. v cc provides power to the device and is also a monitored voltage. when v cc drops below the selected threshold, reset asserts low and remains low for the reset timeout period after v cc rises above the threshold. for better noise immunity, bypass v cc to gnd with a 0.1f capacitor 12 4 3 v cc gnd sc70 top view max6467xsmax6468xs reset mr 4 3 12 v cc gnd sot143 max6467usmax6468us reset mr max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset www.maximintegrated.com maxim integrated 5 pin description pin conigurations downloaded from: http:///
detailed description reset output the max6467 provides an active-low open-drain reset output. the max6468 provides an active-low push-pull reset output. reset asserts low if v cc drops below the selected threshold or if a falling edge occurs on mr . reset remains low for the v cc reset timeout period after v cc increases above the threshold voltage or is one-shot pulsed low for the mr timeout period after a falling edge on mr . manual reset input many p-based products require manual reset capability, allowing the operator, a test technician, or external logic circuitry to initiate a reset. a falling edge on mr asserts reset low. reset is one-shot pulsed low for the mr timeout period after a falling edge on mr . an internal 1.5k ? pullup resistor to v cc allows mr to be left uncon - nected if not used. mr can be driven with ttl or cmos- logic levels, or with open-drain/collector outputs. connect a normally open momentary pushbutton switch from mr to gnd to realize a manual reset function. external debounce circuitry is not required, as the max6467/ max6468 respond to the first falling edge on mr and ignore subsequent falling edges within the reset timeout period and during the mr debounce period (see figure 1). after mr goes high for 150ms (t deb ), the manual reset one-shot is ready to trigger a reset on the next mr falling edge. connect a 0.1f capacitor from mr to gnd when using long cables to provide additional noise immunity (figure 2). figure 1. timing diagram v cc gndgnd mr t rp gnd reset v th switch bounce switch bounce switch bounce t mrp t mrp t deb max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset www.maximintegrated.com maxim integrated 6 downloaded from: http:///
*additional reset timeout options may be available. contact factory for availability. applications information falling v cc transients in addition to issuing a reset to the p during power-up, power-down, and brownout conditions, the max6467/ max6468 are relatively immune to short-duration fall - ing v cc transients (glitches). the typical operating characteristics section shows the maximum transient duration vs. v cc overdrive for which the max6467/ max6468 do not generate a reset pulse. this graph was generated using a falling pulse applied to v cc starting above the actual reset threshold and ending below the threshold by the magnitude indicated (v cc overdrive). the graph indicates the typical maximum pulse width a falling v cc transient can have without initiating a reset pulse. as the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. a 0.1f bypass capacitor from v cc to gnd provides additional transient immunity. ensuring a valid reset output down to v cc = 0v the max6467/max6468 guarantee proper operation down to v cc = +1v. in applications that require valid reset levels down to v cc = 0v, a pulldown resistor to active-low outputs (max6468 only, figure 3) ensures that reset remains valid while the reset output can no longer sink current. this scheme does not work with the open-drain outputs of the max6467. ensure that the resistor value used does not overload the reset output when v cc is above the reset threshold. for most applica - tions, use 100k ? to 1m ? . figure 3. reset valid to v cc = 0v figure 2. functional diagram reset timeout suffix v cc reset timeout period (min/max) (ms) mr timeout period (min/max) (ms) mr rising debounce period (min/max) (ms) d3 150/300 150/300 150/300 d7 1200/2400 150/300 150/300 max6468 v cc gnd reset r1100k ? 1.5k ? v cc mr one-shot/ debounce reset timeout period reset output v cc 1.23v v cc mr reset gnd max6467max6468 max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset www.maximintegrated.com maxim integrated 7 chip information transistor count: 748 process: bicmos reset timeout delay* downloaded from: http:///
suffix v th (min) v th (typ) v th (max) 46 4.509 4.625 4.741 45 4.388 4.500 4.613 44 4.266 4.375 4.484 43 4.193 4.300 4.408 42 4.095 4.200 4.305 41 3.998 4.100 4.203 40 3.900 4.000 4.100 39 3.803 3.900 3.998 38 3.705 3.800 3.895 37 3.608 3.700 3.793 36 3.510 3.600 3.690 35 3.413 3.500 3.588 34 3.315 3.400 3.485 33 3.218 3.300 3.383 32 3.120 3.200 3.280 31 2.998 3.075 3.152 30 2.925 3.000 3.075 29 2.852 2.925 2.998 28 2.730 2.800 2.870 27 2.633 2.700 2.768 26 2.559 2.625 2.691 25 2.438 2.500 2.563 24 2.340 2.400 2.460 23 2.255 2.313 2.370 22 2.133 2.188 2.242 21 2.048 2.100 2.153 20 1.950 2.000 2.050 19 1.853 1.900 1.948 18 1.755 1.800 1.845 17 1.623 1.665 1.707 16 1.536 1.575 1.614 part top mark max6467 xs16d3 agl max6467xs22d3 agm max6467xs26d3 agn max6467xs29d3 ago max6467xs46d3 agp max6467us16d3 kafn max6467us22d3 kafo max6467us26d3 kafp max6467us29d3 kafq max6467us46d3 kafr max6468 xs16d3 agq max6468xs22d3 agr max6468xs26d3 ags max6468xs29d3 agc max6468xs46d3 agb max6468us16d3 kafs max6468us22d3 kaft max6468us26d3 kafu max6468us29d3 kaew max6468us46d3 kafv max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset www.maximintegrated.com maxim integrated 8 reset threshold (-40 c to +85 c) standard versions downloaded from: http:///
note: insert reset threshold suffix (see reset threshold table) after xs or us. insert reset timeout delay (see reset timeout delay table) after d to complete the part number. sample stock is generally held on standard versions only (see standard versions table). standard versions have an order increment requirement of 2500 pieces. nonstandard versions have an order increment requirement of 10,000 pieces. contact factory for availability devices are available in both leaded and lead- free packaging. specify lead-free by replacing t with +t when ordering. t = tape and reel. /v denotes an automotive qualified part. +denotes a lead(pb)-free/rohs-compliant package. *future product contact factory for availability. part temp range pin- package max6467 xs_ _d_-t -40c to +125c 4 sc70-4 max6467xs_ _d_/v+t* -40c to +125c 4 sc70-4 max6467us_ _d_-t -40c to +125c 4 sot143-4 max6468 xs_ _d_-t -40c to +125c 4 sc70-4 max6468us_ _d_-t -40c to +125c 4 sot143-4 package type package code outline no. land pattern no. 4 sc70 x4+1 21-0098 90-0187 4 sot143 u3+1 21-0052 90-0183 max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset www.maximintegrated.com maxim integrated 9 ordering information package information for the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages . note that a +, #, or - in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to the package regardless of rohs status. downloaded from: http:///
revision number revision date description pages changed 2 3/14 added /v opns 1 3 4/14 removed automotive reference from applications section 1 6/14 reversed 4/14 change and added automotive reference back to applications section 1 4 10/14 fixed typo in package information section 9 5 10/15 fixed mr pullup resistance speciication in electrical characteristics table 2 maxim integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim integrated product. no circuit patent licenses are implied. maxim integrated reserves the right to change the circuitry and speciications without n otice at any time. the parametric values (min and max limits) shown in the electrical characteristics table are guaranteed. other parametric values quoted in this data sheet are provided for guidance. maxim integrated and the maxim integrated logo are trademarks of maxim integrated products, inc. max6467/max6468 microprocessor supervisory reset circuits with edge-triggered, one-shot manual reset ? 2015 maxim integrated products, inc. 10 revision history for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim integrateds website at www.maximintegrated.com. downloaded from: http:///
|
