asm161 and asm162 p supervisory circuit ?2010 scillc. all rights reserved. publication order number: januar y 2010 C rev. 2 asm161 /d general description the asm161 and asm162 are cost effective, low power supervisory circuits that monitor power supplies in microprocessor, microcontroller and digital systems. if the power supply drops below the reset threshold level, a reset is asserted and remains asserted for at least 800ms after v cc has r isen above the reset threshold. an improved manual reset architecture gives the system designer additional flexibility. the debounced manual reset input is negative edge triggered. the reset pulse period generated by a mr transition is a minimum of 800 ms and a maximum of 2 sec duration. in addition, the mr input signal is blocked for an additional 49s minimum after the reset pulse ends. during the mr disable period, the microcontroller is guarant eed a time period free of additional manual reset signals. during this period dram contents can be refreshed or other critical system tasks undertaken. low power consumption makes the asm161/162 ideal for use in portable and battery operated equipments. wi th 3v supplies , power consumption is 8w typically and 30w maximum. the asm161 has an open - drain, active - low reset output and requires an external pull - up resistor. the asm162 has an active high reset output. the asm161/162 are offered in compact 4 - pin sot - 143 packages. no external components are required to trim threshold voltage for monitoring different supply voltages. with six different factory set, reset, threshold ranges from 2.63v to 4.63v, the asm161/162 are suitable for monitoring 5v, 3.6v and 3 .0v supplies. the asm161/162 are available in temperature ranges 0c to 70c and - 40c to +85c. reset threshold part suffix voltage (v) l 4.63 m 4.38 j 4.00 t 3.08 s 2.93 r 2.63 key features edge triggered manual reset input single pulse output 49s minimum mr disable period after reset cmos/ttl logic or switch interface debounced input low supply current extends battery life 6a / 15a typ/max at 5.5v 4.5a / 10a typ/max at 3.6v long reset period 0.8 sec minimum, 2 sec maximum two reset p olarity options asm161: active low, open - drain asm162: active high pinout matches the asm811/812 small 4 - pin sot - 143 package two temperature ranges: 0c to 70c and - 40c to +85c applications pdas appliances computers and embedded controllers wirel ess communication systems battery operated and intelligent instruments automotive systems safety systems
asm161 and asm162 rev. 2 | page 2 of 9 | www.onsemi.com typical operating circuit block diagram pin configuration reset is open drain
asm161 and asm162 rev. 2 | page 3 of 9 | www.onsemi.com pin description pin # pin nam e function asm161 asm162 1 1 gnd ground. 2 - reset active - low, open - drain reset output. reset remains low while v cc is below the reset threshold and for 800ms minimum after v cc rises above the reset threshold. an external pull - up resistor is needed. - 2 reset active high reset output. reset remains high while v cc is below the reset threshold and for 800ms after v cc rises above the reset threshold. 3 3 mr manual reset input. a negative going edge transition on mr asserts reset. reset remains ass erted for one reset time - out period (800 ms min). this active - low input has an internal pull - up resistor. it can be driven from a ttl or cmos logic line or shorted to ground with a switch. leave open if unused. 4 4 v cc power supply input voltage. detail ed description the reset function ensures the microprocessor is properly reset and powers up into a known condition after a power failure. reset timing a reset is generated whenever the supply voltage is below the threshold level (v cc < v th ). the reset dur ation is at least 800ms after v cc has risen above the reset threshold and is guaranteed to be no more than 2 seconds. the rest signal remains active as long as the monitored supply voltage is below the internal threshold voltage. the asm161 has an open - drain, active low reset output (which is guaranteed to be in the correct state for v cc down to 1.1v). the asm161 uses an external pull - up resistor. output leakage current is under 1 a. a high resistance value can be used to minimize current drain. the asm162 generates an active - high reset output. part number reset polarity asm161 low (use external pull - up resistor) asm162 high manual reset the asm161/162 have a unique manual r eset circuit. a negative going edge transition on mr initiates the reset. a manual reset generates a single reset pulse of fixed length. the output - reset pulse remains asserted for the reset active time - out period t rp and then clears. once the reset pulse is completed, the mr input remains disabled for at least 49 s but not more than 122s. this period is specified as t mrd . during the mr disabled period, the microcontroller is guaranteed a time period free of new manual reset signals. this period can be used to refresh critical dram contents or other system tasks. the mr pin must be taken high and low again after the t mrd period has been completed to initiate another reset pulse. the manual reset input has an internal 20k pull - up resistor. mr can be left open if not used.
asm161 and asm162 rev. 2 | page 4 of 9 | www.onsemi.com application information gl itch resistance the asm161/162 are relatively immune to short duration negative - going vcc transients/glitches. a vcc transient that goes 100mv below the reset threshold and lasts 20s or less will not typically cause a reset pulse. valid reset with vcc u nder 1.1v to ensure that logic inputs connected to the asm162 reset pin are in a known state when vcc is under 1.1v, a 100k pull - down resistor at reset is needed. the value is not critical. this scheme does not work with the open - drain outputs of asm161. absolute maximum ratings parameter min max unit pin terminal voltage with respect to ground v cc - 0.3 6.0 v r eset, reset and mr - 0.3 v cc + 0.3 v input current at vcc and mr 20 ma rate of rise at vcc 100 v/s power dissipation (ta = 70c) 320 mw operating temperature range - 40 85 c storage temperature range - 65 160 c lead temperature (soldering, 10 sec) 300 c esd rating hbm mm 2 200 kv v note: these are stress ratings only and functional operation is not implied. exposure to absolute maximum ratings for prolong ed time periods may affect device reliability.
asm161 and asm162 rev. 2 | page 5 of 9 | www.onsemi.com electrical characteristics unless otherwise noted, v cc is over the full range and t a = 0 c to 70 c for asm161/162 x c and t a = - 40 c to +85 c for asm161/162 x e devices. typical values at t a = 25 c , v cc = 5v for l/m/j devices, v cc = 3.3v for t/s devices and v cc = 3v for r devices . paramete r symbol conditions min typ max unit input voltage (v cc ) range v cc t a = 0c to 70c 1.1 5.5 v supply current (unloaded) i cc t a = 0c to 70c, t a = - 40c to +85c v cc < 5.5v l/m/j 6 4.5 15 10 a t a = 0c to 70c, t a = - 40c to +85c v cc < 3.6v r/s/ t reset threshold v th l devices t a = 25c note 1 4.56 4.50 4.63 4.70 4.75 v m devices t a = 25c note 1 4.31 4.25 4.38 4.45 4.50 j devices t a = 25c note 1 3.93 3.89 4.00 4.06 4.10 t devices t a = 25c note 1 3.04 3.00 3.08 3.11 3.15 s devices t a = 25c note 1 2.89 2.85 2.93 2.96 3.00 r devices t a = 25c note 1 2.59 2.55 2.63 2.66 2.70 reset threshold temp coefficient t cvth 30 ppm/ c v cc to reset delay v cc = v th to (v th - 100mv) 20 s reset pulse width t rpw t a = 0c to 70c 800 600 1400 2000 2240 ms t a = - 40c to 85c mr minimum pulse width t mr 10 s mr glitch immunity 100 ns mr to reset propagation delay 0.5 s mr input threshold v ih v cc > v th (max), l/m/ j devices 2.3 v v il 0.8 v v ih v cc > v th (max), r/s/t devices 0.7v cc v v il 0.25v cc v mr delay to mr retrigger t mrd t a = 0c to 70c 48 85 122 s t a = - 40c to 85c 85 mr pull - up resistance 10 20 30 k low reset output voltage (asm161) v ol v cc =v th min., i sink =1.2ma, asm161 r/s/t 0.3 v v cc =v th min., i sink =3.2ma, asm161l/m/j 0.4 v cc > 1.1, i sink = 50a 0.3 reset output voltage (asm162) v ol v cc =v th max., i sink =1.2ma, asm162 r/s/t 0.3 v v cc =v th max., i s ink =3.2ma, asm162 l/m/j 0.4 high reset output voltage (asm162) v oh 1.8 asm161 and asm162 rev. 2 | page 6 of 9 | www.onsemi.com package dimensions plastic sot - 143 (4pin)
asm161 and asm162 rev. 2 | page 7 of 9 | www.onsemi.com ordering information part numb er 1 reset threshold (v) temperature (c) pins - package package marking (ll lot code) tin lead devices asm161lcus/t 4.63 0 to 70 4 - sot - 143 tall asm161mcus/t 4.38 0 to 70 4 - sot - 143 tbll asm161jcus/t 4.00 0 to 70 4 - sot - 143 tcll asm161tcus/t 3.08 0 to 70 4 - sot - 143 tdll asm161scus/t 2.93 0 to 70 4 - sot - 143 tell asm161rcus/t 2.63 0 to 70 4 - sot - 143 tfll asm162lcus/t 4.63 0 to 70 4 - sot - 143 tgll asm162mcus/t 4.38 0 to 70 4 - sot - 143 thll asm162jcus/t 4.00 0 to 70 4 - sot - 143 till asm162tcus/t 3.08 0 to 70 4 - so t - 143 tjll asm162scus/t 2.93 0 to 70 4 - sot - 143 tkll asm162rcus/t 2.63 0 to 70 4 - sot - 143 tlll asm161leus/t 4.63 - 40 to 85 4 - sot - 143 tmll asm161meus/t 4.38 - 40 to 85 4 - sot - 143 tnll asm161jeus/t 4.00 - 40 to 85 4 - sot - 143 toll asm161teus/t 3.08 - 40 to 85 4 - sot - 143 tpll asm161seus/t 2.93 - 40 to 85 4 - sot - 143 tqll asm161reus/t 2.63 - 40 to 85 4 - sot - 143 trll asm162leus/t 4.63 - 40 to 85 4 - sot - 143 tsll asm162meus/t 4.38 - 40 to 85 4 - sot - 143 ttll asm162jeus/t 4.00 - 40 to 85 4 - sot - 143 tull asm162teus/t 3.08 - 40 to 85 4 - sot - 143 tvll asm162seus/t 2.93 - 40 to 85 4 - sot - 143 twll asm162reus/t 2.63 - 40 to 85 4 - sot - 143 txll lead free devices asm161lcusf/t 4.63 0 to 70 4 - sot - 143 mall asm161mcusf/t 4.38 0 to 70 4 - sot - 143 mbll asm161jcusf/t 4.00 0 to 70 4 - sot - 143 mcll asm161tcusf/t 3.08 0 to 70 4 - sot - 143 mdll asm161scusf/t 2.93 0 to 70 4 - sot - 143 mell asm161rcusf/t 2.63 0 to 70 4 - sot - 143 mfll asm162lcusf/t 4.63 0 to 70 4 - sot - 143 mgll asm162mcusf/t 4.38 0 to 70 4 - sot - 143 mhll asm162jcusf/t 4.00 0 to 70 4 - sot - 1 43 mill asm162tcusf/t 3.08 0 to 70 4 - sot - 143 mjll asm162scusf/t 2.93 0 to 70 4 - sot - 143 mkll asm162rcusf/t 2.63 0 to 70 4 - sot - 143 mlll note : 1. for parts to be packed in tape and reel, add - t at the end of the part number. on semiconductor lead free p arts are rohs compliant.
asm161 and asm162 rev. 2 | page 8 of 9 | www.onsemi.com part number 1 reset threshold (v) temperature (c) pins - package package marking (ll lot code) asm161leusf/t 4.63 - 40 to 85 4 - sot - 143 mmll asm161meusf/t 4.38 - 40 to 85 4 - sot - 143 mnll asm161jeusf/t 4.00 - 40 to 85 4 - sot - 143 moll asm161teusf/t 3.08 - 40 to 85 4 - sot - 143 mpll asm161seusf/t 2.93 - 40 to 85 4 - sot - 143 mqll asm161reusf/t 2.63 - 40 to 85 4 - sot - 143 mrll asm162leusf/t 4.63 - 40 to 85 4 - sot - 143 msll asm162meusf/t 4.38 - 40 to 85 4 - sot - 143 mtll asm162jeusf/t 4.00 - 40 to 85 4 - sot - 143 mull asm162teusf/t 3.08 - 40 to 85 4 - sot - 143 mvll asm162seusf/t 2.93 - 40 to 85 4 - sot - 143 mwll asm162reusf/t 2.63 - 40 to 85 4 - sot - 143 mxll notes: 1. for parts to be packed in tape and reel, add - t at the end of the part number. on semiconductor lead free parts are rohs compliant.
asm161 and asm162 on semiconductor and are registered trademarks of semiconductor components industries, llc (scillc). scillc reserves the right to make changes wit hout further notice to any products herein. scillc makes no warranty, representat ion or guarantee regarding the suitability of its products for any particular purpose, nor does scillc assume any liability a rising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. typical parameters which may be provided in scillc data sheets and/or specifications can and do vary in different applications and ac tual performance may vary over time. all operating parameters, including typicals must be validated for each customer application by customer's technical experts. scillc does not convey any license under its patent rights nor the rights of others. scillc products are not designed, intended, or authorized for use a s components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the scillc product could create a situation whe re personal injury or death may occur. should buyer purchase or use scillc products for any such unintended or unauthorized application, buyer shall indemnify and hold scillc and its office rs, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or d eath associated with such unintended or unauthorized use, even if such claim alleges that scillc was negligent regarding the design or manufacture of the part. scillc is an equal opportunity/affirmative action employer. u.s patent pending; timing - safe and active bead are trademarks of pulsecore semiconductor, a wholly owned subsidiary of on semiconductor. this literatur e is subject t o all applicable copyright laws and is not for resale in any manner. ? publication ordering information literature fulfillment: literature distribution center for on semiconductor p.o. box 5163, denver, colorado 80217 usa phone : 303 - 675 - 2175 or 800 - 344 - 3 860 toll free usa/canada fax : 303 - 675 - 2176 or 800 - 344 - 3867 toll free usa/canada email : orderlit@onsemi.com ? n. american technical support : 800 - 282 - 9855 toll free usa/canada europe, middle east and africa technical support: phone: 421 33 790 2910 japan customer focus center phone: 81 - 3 - 5773 - 3850 ? on semiconductor website: www.onsemi.com ? order literature: http://www.onsemi.com/orderlit for additional information, please contact your local sales representative ? ?
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