low voltage supervisory circuits with watchdog & manual reset in 5-lead sot-23 preliminary technical data adm6821Cadm6825 rev. pra information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. specifications subject to chan ge without notice. no license is granted by implication or otherwise under any patent or patent ri ghts of analog devices. trademarks and registered trademarks are the proper ty of their respective companies. one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781.329.4700 www.analog.com fax: 781.326.8703 ? 2004 analog devices, inc. all rights reserved. features precision low voltage monitoring down to 1.8v 9 reset threshold options: 1.58v to 4.63v 140ms (min) reset timeout watchdog timer with 1.6s timeout manual reset input reset output stages push-pull active-low open-drain active-low push-pull active-high low power consumption (3a) guaranteed reset output valid to v cc =1v power supply glitch immunity specified from -40c to +125c 5-lead sot-23 package applications microprocessor systems computers controllers intelligent instruments portable equipment general description the adm6821-adm6825 are supervisory circuits which monitor power supply voltage levels and code execution integrity in microprocessor-based systems. as well as providing power-on-reset signals, an on-chip watchdog timer can reset the microprocessor if it fails to strobe within a preset timeout period. a reset signal can also be asserted by means of an external push-button, through a manual reset input. the three parts feature different combinations of watchdog input, manual reset input and output stage configuration, as shown in table 1. functional block diagram
each part is available in a choice of 9 reset threshold options ranging from 1.58v to 4.63v. the reset and watchdog timeout periods are fixed at 140ms (min) and 1.6s (typ), respectively. the adm6821-adm6825 are available in 5-lead sot-23 packages and typically consum e only 3a, making them suitable for use in low power portable applications . table 1. selection table output stage part no. watchdog timer manual reset reset reset adm6821 yes yes - push-pull adm6822 yes yes open-drain - adm6823 yes yes push-pull - adm6824 yes - push-pull push-pull adm6825 - yes push-pull push-pull
adm6821Cadm6825 preliminary technical data rev.pra | page 2 of 7 adm6821Cadm6825specifications table 2. v cc =4. 5v to 5.5v for adm682_l/m, v cc =2.7v to 3.6v for adm682_t/s/r, v cc =2.1v to 2.75v for adm682_z/y, v cc =1.53v to 2.0v for adm682_w/v, t a =-40c to +125c, unless otherwise noted. parameter min typ max units test conditions/comments supply v cc operating voltage range 1 5.5 v t a =0c to +70c 1.2 5.5 v t a =--40c to +125c supply current (wdi and mr unconnected) 10 24 a v cc =5.5v, no load, t a =--40c to +85c 30 a v cc =5.5v, no load, t a =--40c to +125c 7 16 a v cc =3.6v, no load, t a =--40c to +85c 25 a v cc =3.6v, no load, t a =--40c to +125c 5 12 a v cc =3.6v, no load, t a =--40c to +85c (adm6825 only) 20 a v cc =3.6v, no load, t a =--40c to +125c (adm6825 only) reset threshold voltage adm682_l 4.50 4.63 4.75 v t a =-40c to +85c 4.47 4.78 v t a =-40c to +125c adm682_m 4.25 4.38 4.50 v t a =-40c to +85c 4.22 4.53 v t a =-40c to +125c adm682_t 3.00 3.08 3.15 v t a =-40c to +85c 2.97 3.17 v t a =-40c to +125c adm682_s 2.85 2.93 3.00 v t a =-40c to +85c 2.83 3.02 v t a =-40c to +125c adm682_r 2.55 2.63 2.70 v t a =-40c to +85c 2.53 2.72 v t a =-40c to +125c adm682_z 2.25 2.32 2.38 v t a =-40c to +85c 2.24 2.40 v t a =-40c to +125c adm682_y 2.12 2.19 2.25 v t a =-40c to +85c 2.11 2.27 v t a =-40c to +125c adm682_w 1.62 1.67 1.71 v t a =-40c to +85c 1.61 1.72 v t a =-40c to +125c adm682_v 1.52 1.58 1.62 v t a =-40c to +85c reset threshold temperature coefficient 60 ppm/c reset threshold hysteresis 2x v th mv reset timeout period 140 200 280 ms 100 320 ms v cc to reset delay 20 s v cc = v th to (v th - 100mv) reset output voltage low 0.4 v v cc >=4.25v, i sink =3.2ma, reset asserted 0.3 v v cc >=2.55v, i sink =1.2ma, reset asserted 0.3 v v cc >=1.25v, i sink =100ua, reset asserted 0.3 v v cc >=1.0v, i sink =50ua, reset asserted, t a =-40c to +85c reset output voltage high 0.8 v cc v v cc >=4.75v, i source =800ua, reset not asserted
preliminary technical data adm6821Cadm6825 rev.pra | page 3 of 7 parameter min typ max units test conditions/comments 0.8 v cc v v cc >=3.15v, i source =500ua, reset not asserted 0.8 v cc v v cc >=1.8v, i source =200ua, reset not asserted reset output voltage high 0.8 v cc v cc >=4.25v, i source =800ua, reset asserted 0.8 v cc v cc >=2.55v, i source =500ua, reset asserted 0.8 v cc v cc >=1.50v, i source =100ua, reset asserted 0.8 v cc v cc >=1.0v, i source =1ua, reset asserted, t a =-40c to +85c reset output voltage low 0.4 v v cc >=4.75v, i sink =3.2ma, reset not asserted 0.3 v v cc >=3.15v, i sink =1.2ma, reset not asserted 0.3 v v cc >=1.8v, i sink =500ua, reset not asserted watchdog input (adm6821-adm6824) watchdog timeout period 1.12 1.6 2.40 s wdi pulse width 50 ns v il =0.4v, v ih =0.8 v cc , wdi input threshold v il 0.3xv cc v v ih 0.7xv cc v wdi input current 120 160 a v wdi = v cc , time average -20 -15 a v wdi =0, time average manual reset input (adm6821-adm6823/adm6825) mr input threshold 0.3xv cc v 0.7xv cc v mr input pulse width 1 s mr glitch rejection 100 ns mr pull-up resistance 25 50 75 k mr to reset delay 200 ns absolute maximum ratings table 3. t a = 25c unless otherwise noted. parameter rating v cc -0.3v to +6v output current (reset, reset ) 20ma operating temperature range -40c to +125c storage temperature range -65c to +150c ja thermal impedance 270c/w lead temperature soldering (10 sec) 300c vapour phase (60 sec) 215c infrared (15 sec) 220c stresses above those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability.
adm6821Cadm6825 preliminary technical data rev.pra | page 4 of 7 pin configurations and functional descriptions
!"#$
!"#$
!"#$
!"#$
table 4. pin functional descriptions pin no. name description 1 reset (adm6822/23/24/25) active-low reset output, which is asserted whenever v cc is below the reset.threshold, v th . open-drain output stage for adm6822. push-pull output stage for adm6823/24/25. reset (adm6821) active-high reset output 2 gnd ground 3 mr (adm6821/22/23) manual reset input. this is an active-low in put which, when forced low for at least 1s, generates a reset. features a 52k internal pull-up. reset (adm6824/adm6825) active- high push-pull reset output. 4 wdi (adm6821/22/23/24) watchdog input. generates a reset if the volt age on the pin remains low or high for the duration of the watchdog timeout. the timer is cleared if a logic transi tion occurs on this pin or if a reset is generated. mr (adm6825) manual reset input. 5 v cc power supply voltage being monitored esd caution ` esd (electrostatic discharge) sensitive device. electrosta tic charges as high as 4000 v readily accumulate on the human body and test equipment and can discharge with out detection. although this product features proprietary esd protection circuitry, permanent dama ge may occur on devices subjected to high energy electrostatic discharges. therefore, proper esd precautions are recommended to avoid performance degradation or loss of functionality.
preliminary technical data adm6821Cadm6825 rev. pra | page 5 of 7 ordering guide model reset threshold (v) temperature range quantity package type branding adm6821lart-rl 4.63 -40c to +125c 10k sot-23-5 n0a adm6821lart-rl7 4.63 -40c to +125c 3k sot-23-5 n0a adm6821mart-rl 4.38 -40c to +125c 10k sot-23-5 n0a adm6821mart-rl7 4.38 -40c to +125c 3k sot-23-5 n0a adm6821tart-rl 3.08 -40c to +125c 10k sot-23-5 n0a adm6821tart-rl7 3.08 -40c to +125c 3k sot-23-5 n0a adm6821sart-rl 2.93 -40c to +125c 10k sot-23-5 n0a adm6821sart-rl7 2.93 -40c to +125c 3k sot-23-5 n0a adm6821rart-rl 2.63 -40c to +125c 10k sot-23-5 n0a adm6821rart-rl7 2.63 -40c to +125c 3k sot-23-5 n0a adm6821zart-rl 2.32 -40c to +125c 10k sot-23-5 n0a adm6821zart-rl7 2.32 -40c to +125c 3k sot-23-5 n0a ADM6821YART-RL 2.19 -40c to +125c 10k sot-23-5 n0a ADM6821YART-RL7 2.19 -40c to +125c 3k sot-23-5 n0a adm6821wart-rl 1.67 -40c to +125c 10k sot-23-5 n0a adm6821wart-rl7 1.67 -40c to +125c 3k sot-23-5 n0a adm6821vart-rl 1.58 -40c to +125c 10k sot-23-5 n0a adm6821vart-rl7 1.58 -40c to +125c 3k sot-23-5 n0a adm6822lart-rl 4.63 -40c to +125c 10k sot-23-5 n0b adm6822lart-rl7 4.63 -40c to +125c 3k sot-23-5 n0b adm6822mart-rl 4.38 -40c to +125c 10k sot-23-5 n0b adm6822mart-rl7 4.38 -40c to +125c 3k sot-23-5 n0b adm6822tart-rl 3.08 -40c to +125c 10k sot-23-5 n0b adm6822tart-rl7 3.08 -40c to +125c 3k sot-23-5 n0b adm6822sart-rl 2.93 -40c to +125c 10k sot-23-5 n0b adm6822sart-rl7 2.93 -40c to +125c 3k sot-23-5 n0b adm6822rart-rl 2.63 -40c to +125c 10k sot-23-5 n0b adm6822rart-rl7 2.63 -40c to +125c 3k sot-23-5 n0b adm6822zart-rl 2.32 -40c to +125c 10k sot-23-5 n0b adm6822zart-rl7 2.32 -40c to +125c 3k sot-23-5 n0b adm6822yart-rl 2.19 -40c to +125c 10k sot-23-5 n0b adm6822yart-rl7 2.19 -40c to +125c 3k sot-23-5 n0b adm6822wart-rl 1.67 -40c to +125c 10k sot-23-5 n0b adm6822wart-rl7 1.67 -40c to +125c 3k sot-23-5 n0b adm6822vart-rl 1.58 -40c to +125c 10k sot-23-5 n0b adm6822vart-rl7 1.58 -40c to +125c 3k sot-23-5 n0b adm6823lart-rl 4.63 -40c to +125c 10k sot-23-5 n0c adm6823lart-rl7 4.63 -40c to +125c 3k sot-23-5 n0c adm6823mart-rl 4.38 -40c to +125c 10k sot-23-5 n0c adm6823mart-rl7 4.38 -40c to +125c 3k sot-23-5 n0c adm6823tart-rl 3.08 -40c to +125c 10k sot-23-5 n0c adm6823tart-rl7 3.08 -40c to +125c 3k sot-23-5 n0c adm6823sart-rl 2.93 -40c to +125c 10k sot-23-5 n0c adm6823sart-rl7 2.93 -40c to +125c 3k sot-23-5 n0c adm6823rart-rl 2.63 -40c to +125c 10k sot-23-5 n0c adm6823rart-rl7 2.63 -40c to +125c 3k sot-23-5 n0c adm6823zart-rl 2.32 -40c to +125c 10k sot-23-5 n0c adm6823zart-rl7 2.32 -40c to +125c 3k sot-23-5 n0c adm6823yart-rl 2.19 -40c to +125c 10k sot-23-5 n0c adm6823yart-rl7 2.19 -40c to +125c 3k sot-23-5 n0c
adm6821Cadm6825 preliminary technical data rev.pra | page 6 of 7 ordering guide (contd.) model reset threshold (v) temperature range quantity package type branding adm6823wart-rl 1.67 -40c to +125c 10k sot-23-5 n0c adm6823wart-rl7 1.67 -40c to +125c 3k sot-23-5 n0c adm6823vart-rl 1.58 -40c to +125c 10k sot-23-5 n0c adm6823vart-rl7 1.58 -40c to +125c 3k sot-23-5 n0c adm6824lart-rl 4.63 -40c to +125c 10k sot-23-5 n0d adm6824lart-rl7 4.63 -40c to +125c 3k sot-23-5 n0d adm6824mart-rl 4.38 -40c to +125c 10k sot-23-5 n0d adm6824mart-rl7 4.38 -40c to +125c 3k sot-23-5 n0d adm6824tart-rl 3.08 -40c to +125c 10k sot-23-5 n0d adm6824tart-rl7 3.08 -40c to +125c 3k sot-23-5 n0d adm6824sart-rl 2.93 -40c to +125c 10k sot-23-5 n0d adm6824sart-rl7 2.93 -40c to +125c 3k sot-23-5 n0d adm6824rart-rl 2.63 -40c to +125c 10k sot-23-5 n0d adm6824rart-rl7 2.63 -40c to +125c 3k sot-23-5 n0d adm6824zart-rl 2.32 -40c to +125c 10k sot-23-5 n0d adm6824zart-rl7 2.32 -40c to +125c 3k sot-23-5 n0d adm6824yart-rl 2.19 -40c to +125c 10k sot-23-5 n0d adm6824yart-rl7 2.19 -40c to +125c 3k sot-23-5 n0d adm6824wart-rl 1.67 -40c to +125c 10k sot-23-5 n0d adm6824wart-rl7 1.67 -40c to +125c 3k sot-23-5 n0d adm6824vart-rl 1.58 -40c to +125c 10k sot-23-5 n0d adm6824vart-rl7 1.58 -40c to +125c 3k sot-23-5 n0d adm6825lart-rl 4.63 -40c to +125c 10k sot-23-5 n0e adm6825lart-rl7 4.63 -40c to +125c 3k sot-23-5 n0e adm6825mart-rl 4.38 -40c to +125c 10k sot-23-5 n0e adm6825mart-rl7 4.38 -40c to +125c 3k sot-23-5 n0e adm6825tart-rl 3.08 -40c to +125c 10k sot-23-5 n0e adm6825tart-rl7 3.08 -40c to +125c 3k sot-23-5 n0e adm6825sart-rl 2.93 -40c to +125c 10k sot-23-5 n0e adm6825sart-rl7 2.93 -40c to +125c 3k sot-23-5 n0e adm6825rart-rl 2.63 -40c to +125c 10k sot-23-5 n0e adm6825rart-rl7 2.63 -40c to +125c 3k sot-23-5 n0e adm6825zart-rl 2.32 -40c to +125c 10k sot-23-5 n0e adm6825zart-rl7 2.32 -40c to +125c 3k sot-23-5 n0e adm6825yart-rl 2.19 -40c to +125c 10k sot-23-5 n0e adm6825yart-rl7 2.19 -40c to +125c 3k sot-23-5 n0e adm6825wart-rl 1.67 -40c to +125c 10k sot-23-5 n0e adm6825wart-rl7 1.67 -40c to +125c 3k sot-23-5 n0e adm6825vart-rl 1.58 -40c to +125c 10k sot-23-5 n0e adm6825vart-rl7 1.58 -40c to +125c 3k sot-23-5 n0e
preliminary technical data adm6821?adm6825 rev. pra | page 7 of 7 outline dimensions pin 1 1.60 bsc 2.80 bsc 1.90 bsc 0.95 bsc 1 3 4 5 2 0.22 0.08 10 5 0 0.50 0.3 0.15 max seating plane 1.45 max 1.30 1.15 0.90 2.90 bsc 0. 0.45 0.3 compliant to jedec standards mo-178aa figure 1. 5-lead small outline transistor package [sot-23] (rt-5) dimensions shown in millimeters 2 nalog deices nc. ll rights resered. trademarks and registered trademarks are the roer t o their resectie comanies. printed in the .s..
|
