asm1834a/d alliance semiconductor 2575 augustine drive . santa clara, ca 95054 . tel: 408.855.4900 . fax: 408.855.4999 . www.alsc.com notice: the information in this document is subject to change without notice rev 1.0 dual 5v and 3.3v p power su pply supervisor with manual reset october 2003 general description the asm1834 supervisors simultaneously monitor both 3.3v and 5v power sources and generate reset signals when either supply is out of tolerance. when an out-of-tolerance is detected, the output-reset signal of the affected supply becomes active and resets the system microprocessor/ microcontroller. on power-up and after the supply voltage returns to an in-tolerance condition, the reset signal remains active for approximately 350ms. this allows the power supply and system microprocessor to stabilize. tolerance levels are independently selectable for both supplies. tolerance options are 5% and 10% percent for the 5v supply and 10% and 20% percent for the 3.3v supply. the asm1834 and asm1834d have push-pull reset output stages. the asm1834a reset outputs are open drain devices that can both be connected to ei ther 5v or 3.3v supply. the asm1834 and asm1834a have active low reset outputs. the asm1834d has active high reset outputs. all devices can generate reset signals through an internally debounced pushbutton reset input that affects both reset outputs. all devices operate over the ex tended industrial temperature range. devices are available in 8-pin dip, surface mount 8-pin so and 8-pin microso packages. die are also available. key features ? monitor 5v and 3.3v supplies simultaneously ? 5v and 3.3v power-on reset ? 350ms reset time ? debounced pushbutton reset input ? push-pull cmos output ?asm1834, asm1834d ?eliminates external pull-up resistors ?active low (asm1834), high (asm1834d) ? open drain output ?asm1834a ?active low ? selectable 5v and 3.3v trip point tolerance ? internal power drawn from highest input voltage, 5v or 3.3v ? precision temperature-compensated voltage reference and comparator ? low cost surface mount so, compact microso and dip packages. ? wide operating temperat ure, -40c to +85c applications ? microprocessors ? pdas, hand-held pcs ? embedded controllers ? telecommunication systems ? power supplies ? wireless / cellular systems ? networking hardware typical operating circuit +5v 3.3v 5v in reset pbrst 5vtol gnd 3.3vtol 3.3v in reset gnd p 3.3v 5v asm1834
asm1834a/d 2 of 10 notice: the information in this docum ent is subject to change without notice dual 5v and 3.3v p power suppl y supervisor with manual reset rev 1.0 october 2003 block diagram pin configuration pin description pin # pin name function 1 5v in 5v power supply input. 2 5v reset 5v reset 5v reset output (active low, asm1834 , asm1834a. open drain outputs for asm1834a). 5v reset output (active high, as1834d). 35v tol 5v input tolerance select: 10% tolerance for 5vtol= 5v in and 5% tolerance for 5vtol = gnd 4 gnd ground. 5 pbrst debounced manual pushbutton reset input (40k ? internal pull-up). 63.3v tol 3.3v input tolerance select: 20 % tolerance for 3.3vtol = 3.3v in and 10% tolerance for 3.3vtol=gnd. 7 3.3v reset 3.3v reset 3.3v reset output (active low, asm1834, asm1834a. open drain outputs for asm1834a). 3.3v reset output (active high, as1834d). 8 3.3v in 3.3v power supply input. 1 2 3 4 5 6 7 8 5v in 5v reset * 5v tol gnd 3.3v in 3.3v reset * pbrst 3.3v tol asm1834 asm1834a asm1834d * as1834d reset outputs are active high (5v reset and 3.3v reset) outputs are open-drain for as1834a. 5v tolerance bias low tc 3.3v tolerance pushbutton level for asm1834d 350ms delay 5 v in 5 vtol pbrst 3.3 v in 3.3 vtol gnd 3.3v reset 3.3v reset (asm1834d) 5v reset 5v reset asm1834 350ms delay reference bias sense and debounce for asm1834d - + - asm1834a 5v reset 3.3v reset 40k ? (asm1834d) +
3 of 10 notice: the information in this docum ent is subject to change without notice dual 5v and 3.3v p power supply supervisor with manual reset asm1834a/d rev 1.0 october 2003 detailed description operation power monitor the asm1834 supervisors simultaneously detect out-of- tolerance power supply conditions on both 3.3v and 5v power supplies. if the voltages at 5vin or 3.3vin are outside the tolerance band, the reset for the falling supply voltage becomes active. when the monitored supply returns to an in- tolerance state, the reset remains active for approximately 350ms before returning to the inactive state. on power-up, the reset signals are kept active for approximately 350ms after the power supply voltages have reached the selected tolerance. this allows the power supply and microprocessor to stabilize before the reset is removed. all supply current for the asm1834 devices is drawn from the input (5v in or 3.3v in ) with the highest voltage level. the outputs draw current from their input supplies 5v in and 3.3v in . reset signal polarity and output stage structure the asm1834 and the asm1834a supervisors have active low reset signals. the asm1834d reset outputs are active high. the asm1834 and the asm1834d have cmos push-pull output satges. the asm1834a has open drain reset outputs. part # reset polarity output stage configuration asm1834 low push-pull ASM1834EMA low push-pull asm1834s low push-pull asm1834a low open drain asm1834aema low open drain asm1834as low open drain asm1834d high push-pull asm1834dema high push-pull asm1834ds high push-pull ~ ~ ~ ~ ~ ~ v oh v ol t rpu reset reset v intp (min) v intp (max) v intp t r v in figure 1: timing diagram : power up ~ ~ ~ ~ ~ ~ v oh v ol v intp (max) v intp v intp (min) reset reset t f v in t rpd figure 2: timing diagram : power down reset slews withv cc
4 of 10 notice: the information in this docum ent is subject to change without notice dual 5v and 3.3v p power supply supervisor with manual reset asm1834a/d rev 1.0 october 2003 manual reset operation push-button switch input, pbrst , allows the user to override the internal trip point detection circuits and issue reset signals. the pushbutton input is debounced and is pulled high through an internal 40k ? resistor. when at least one of the reset outputs is not asserted, a push button initiated reset signal can be issued by holding pbrst low for at least 2ms. when pbrst is held low, both resets become active and remain active for approximately 350ms after pbrst returns high. (see figures 3 and 4). reset output signal reset output signals are valid as long as either voltage at 5v in or 3.3v in is above 1.2v. in addition, the asm1834 has push-pull outputs that can remain valid below a 1.2v input level. to sink current below 1.2v, a resistor should be connected from the reset output to ground. this resistor guarantees a valid reset signal down to 0v. a 100k ? value is suggested. the as1834a open drain reset outputs require pull-up resistors and must be low enough in value to pull the output into a high state. resistor value is not critical in most applications and a value of 10k ? is suggested. (see figures 5 and 6). the asm1834a open drain reset outputs can be connected to the same potential through a single pull-up resistor. in this configuration a failure on eith er supply will generate an active low reset. if the inputs are pulled-up to different voltages, the reset outputs (pin 2 and pin 7) cannot be connected to form a wired ?and?(see figure 7). ~ ~ ~ ~ ~ ~ v oh v ol reset reset pbrst t pb t pdly v ih t rst figure 4: timing diagram: pushbutton reset 1 2 3 4 5 6 7 8 3.3v 5v 3.3v in 3.3v reset 5vtol gnd pbrst 5v in 5v reset 3.3vtol asm1834 figure 3: push button reset reset p input 100k ? figure 5: asm1834 reset valid to 0v 1 2 3 4 5 6 7 8 3.3v 5v 3.3v in 3.3v reset 5vtol gnd pbrst 5v in 5v reset 3.3vtol asm1834 figure 6: asm1834a open dr ain output pull-up resistor 10k ? 10k ? v il
5 of 10 notice: the information in this docum ent is subject to change without notice dual 5v and 3.3v p power suppl y supervisor with manual reset asm1834a/d rev 1.0 october 2003 trip point tolerance selection the 3.3vtol and 5vtol inputs allow independent sel;ection of the reset trip points. if 5vtol is connected to the 5v supply input, a 10% tolerance is sele cted. if 5vtol is grounded, a 5% tolerance is selected. if 3.3vtol is connected to the 3.3v supply input, a 20% tolerance is selected. if 3.3vtol is grounded, a 10% tolerance is selected. (refer table below). the 3.3vtol and 5vtol tolerance select inputs should be tied to the ground or to the respective input supply voltage pin, 3.3v in or 5v in . tolerance select 3.3v input 5v input 3.3v tolerance trip point (v) 5v tolerance trip point (v) min nom max min nom max 5vtol = 5v in - - - - 10% 4.25 4.38 4.49 5vtol = gnd - - - - 5% 4.5 4.63 4.75 3.3vtol = 3.3v in 20% 2.47 2.55 2.64 - - - - 3.3vtol = gnd 10% 2.80 2.88 2.97 - - - - 1 2 3 4 5 6 7 8 5v in 5vreset 3.3vreset 5v or 3.3v 3.3v in 5v tol gnd 3.3v tol pbrst 3.3v asm1834a 5v 10k ? figure 7: asm1834a wired ?and? connection
asm1834a/d 6 of 10 notice: the information in this docum ent is subject to change without notice dual 5v and 3.3v p power suppl y supervisor with manual reset rev 1.0 october 2003 absolute maximum ratings recomended dc operating conditions recomended dc operating condition over the operating temperatur e range of -40c to +85c. all voltages are referenced to ground. parameter min max unit voltage on vcc -0.5 7 v voltage on 5v reset -0.5 +5v in + 0.5v v voltage on 3.3v reset -0.5 +3.3v in + 0.5v v voltage on pbrst and reset outputs -0.5 (+5v in + 0.5v) or (+3.3v in + 0.5v) whichever is greater operating temperature range -40 +85 c soldering temperature (for 10 sec) - 260 c storage temperature -55 +125 c note: 1. voltages are measured with respect to ground 2. these are stress ratings only and functional implic ation is not implied. exposure to absolute maximum ratings for extended periods may affect device reliability. parameter symbol conditions min typ max unit 5v supply voltage 5v in 1.2 5.5 v 3.3v supply voltage 3.3v in 1.2 5.5 pbrst input high level v ih both 3.3v in and 5v in >=2.7v 2 v inmax + 0.3 v pbrst input high level v ih both 3.3v in and 5v in <=2.7v v inmax - 0.4 v pbrst input low level v il -0.3 0.5 v
asm1834a/d 7 of 10 notice: the information in this docum ent is subject to change without notice dual 5v and 3.3v p power suppl y supervisor with manual reset rev 1.0 october 2003 dc electrical characteristics unless otherwise noted, v in = 1.2v to 53.5v and specificat ions are over the operating tem perature range of -40c to 85c. recomended dc operating condition over the operating temperatur e range of -40c to +85c. all voltages are referenced to ground. parameter symbol conditions min typ max unit output current i oh output = 2.4v. either 3.3v in or 5.5v in >=2.7v (asm1834/1834d only) 350 a output current i ol output = 0.4v. either 3.3v in or 5.5v in >=2.7v (asm1834/1834d only) 10 ma output voltage v oh v in - 0.1v v input leakage i il -1.0 +1.0 a 5v operating current i cc 3.3v in and 5v in <=5.5v, reset out- puts open. 16 30 a 3.3v operating current i cc 3.3v in and 5v in <=3.6v, reset out- puts open. 12 25 a 5v trip point v intp 5vtol = gnd 4.50 4.63 4.75 v 5v trip point v intp 5vtol = 5v in 4.25 4.38 4.49 v 3.3v trip point v intp 3.3vtol = gnd 2.80 2.88 2.97 v 3.3v trip point v intp 3.3vtol = 3.3v in 2.47 2.55 2.64 v output capacitance c out 10 pf pbrst manual reset minimum low time t pb 2ms pbrst stable low to reset active t pdly 2ms reset active time t rst 200 350 500 ms v cc slew rate t f v intp (max) to v intp (min) 300 s v cc slew rate t r v intp (min) to v intp (max) 0ns v cc detect to reset or reset t rpu t rise = 5s 200 350 500 ms v cc detect noise immunity t rpd 2s
8 of 10 notice: the information in this docum ent is subject to change without notice dual 5v and 3.3v p power supply supervisor with manual reset asm1834a/d rev 1.0 october 2003 package information microso (8-pin) so (8-pin) plastic dip (8-pin) inches millimeteres min max min max microso (8-pin) a - 0.0433 - 0.10 a1 0.0020 0.0059 0.050 0.15 a2 0.0295 0.0374 0.75 0.95 b 0.0098 0.0157 0.25 0.40 c 0.0051 0.0091 0.13 0.23 d 0.1142 0.1220 2.90 3.10 e 0.0256 bsc 0.65 bsc e 0.193 bsc 4.90 bsc e1 0.1142 0.1220 2.90 3.10 l 0.0157 0.0276 0.40 0.70 a0606 so (8-pin) a 0.053 0.069 1.35 1.75 a1 0.004 0.010 0.10 0.25 b 0.013 0.020 0.33 0.51 c 0.007 0.010 0.19 0.25 e 0.050 1.27 e 0.150 0.157 3.80 4.00 h 0.228 0.244 5.80 6.20 l 0.016 0.050 0.40 1.27 d 0.189 0.197 4.80 2.00 plastic dip (8-pin) a - 0.210 - 5.33 a1 0.015 - 0.38 - a2 0.115 0.195 2.92 4.95 b 0.014 0.022 0.36 0.56 b2 0.045 0.070 1.14 1.78 b3 0.030 0.045 0.80 1.14 d 0.355 0.400 9.02 10.16 d1 0.005 - 0.13 - e 0.300 0.325 7.62 8.26 e1 0.240 0.280 6.10 7.11 e 0.100 - 2.54 ea 0.300 - 7.62 eb - 0.430 - 10.92 ec - 0.060 l 0.115 0.150 2.92 3.81 e1 e d a a1 a2 e b c l a 0.10mm 0.004in l c a a1 e h d d d1 a a1 a2 l b b2 e e1 c ea eb 0 - 15
asm1834a/d 9 of 10 notice: the information in this docum ent is subject to change without notice dual 5v and 3.3v p power suppl y supervisor with manual reset rev 1.0 october 2003 ordering information part number reset polarity operating temperature range output stage package asm1834 low -40c to 85c push-pull 8-dip ASM1834EMA low -40c to 85c push-pull microso asm1834s low -40c to 85c push-pull 8-so asm1834/d low 25c push-pull dice asm1834a low -40c to 85c open drain 8-dip as1834aema low -40c to 85c open drain microso asm1834as low -40c to 85c open drain 8-so asm1834a/d low 25c open drain dice asm1834d high -40c to 85c push-pull 8-dip asm1834dema high -40c to 85c push-pull microso asm1834ds high -40c to 85c push-pull 8-so asm1834d/d high 25c push-pull dice
alliance semiconductor corporation 2575, augustine drive, santa clara, ca 95054 tel: 408 - 855 - 4900 fax: 408 - 855 - 4999 www.alsc.com copyright ? alliance semiconductor all rights reserved part number: asm1834a/d document version: 1.0 ? copyright 2003 alliance semiconductor corporation. all rights reserved. our three-point logo, our name and intelliwatt are tr ademarks or registered trademarks of alliance. all other brand and product names may be the trademarks of their respective companies. allia nce reserves the right to make changes to this document and its products at any time without notice. alliance assumes no responsibility for any errors that may appear in this document. the data contained herein represents al liance's best data and/or estimates at the time of issuance. al liance reserves the right to change or correct this data at any time, without notice. if the product described herein is under development, signifi cant change s to these specifications are possible. the information in this product data sheet is intended to be general descriptive information for p otential customers and users, and is not intended to operate as, or provide, any guarantee or warrantee to any user or customer. alliance does not ass ume any responsibility or liability arising out of the application or use of any prod uct described herein, and disclaims any express or implied warran ties related to the sale and/or use of alliance products including liability or warrant ies related to fitness for a particular purpose, merchantability, or infringement of any intellectual property rights, except as express agreed to in al liance's terms and conditions of sale (which are available from alliance). all sales of alliance products are made exclusively accord ing to alliance's terms and conditions of sale. the purchase of products from alli ance does not convey a license under any patent rights, copyrights; mask work s rights, trademarks, or any other intellectual property rights of alliance or third parties. alliance does not authorize its products for use as crit ical components in life-supporti ng systems where a malfunction or failure may reasonably be expected to result in sign ificant injury to the user, and the inclusio n of alliance products in such life-support ing systems implies that the manufacturer assumes all risk of such use and agrees to indemnify alliance against all claims arising from such use. asm1834a/d
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