unisonic technologies co., ltd uic811 cmos ic www.unisonic.com.tw 1 of 8 copyright ? 2012 unisonic technologies co., ltd qw-r502-317.h microprocessor reset circuits ? description the utc uic811 series are resetting circuits which can monitor power supplies especially in microprocessor based systems. in normal operation, the utc uic811 series can assert a reset under any of the following situatio n: the power supply drops below a designated reset threshold level (which is available for 3v or 3.3v or 5v system) or mr is forced low. there is an internal active low reset output which has already been guaranteed to remain asserted for at 140ms least while v cc rises above the designed threshold level. ? features * voltage monitor for 3v or 3.3v or 5v power supplies * valid reset remains with v cc as low as 1v * typical supply current: 5a * fixed 140ms minimum reset pulse width * with manual reset input ? ordering information ordering number package packing lead free halogen free UIC811L-X-AD4-R uic811g-x-ad4-r sot-143 tape reel uic811l-x-ae2-r uic811g-x-ae2-r sot-23-3 tape reel uic811l-x-ae3-r uic811g-x-ae3-r sot-23 tape reel note: x: output voltage, refe r to marking information.
uic811 cmos ic unisonic technologies co., ltd 2 of 8 www.unisonic.com.tw qw-r502-317.h ? marking information package voltage code marking sot-143 a : 2.63v b : 2.93v c : 3.08v d: 4.00v e: 4.38v f: 5.00v sot-23 sot-23-3 ? pin configuration 3 1 v cc 2 gnd reset sot-143 sot-23/sot-23-3 ? pin description pin no. pin name description sot-23 sot-23-3 sot-143 3 1 gnd ground 2 2 reset this pin will fall low after the v cc ?s falling below the reset threshold voltage and it also can remain asserted for at least 140ms min after v cc ?s rising upon the reset threshold. - 3 mr input of manual reset. a reset can be forced by a logic low on mr . as the mr is held low, the reset will remain asserted, and until the mr rise high, the reset will remain 140ms min at least. when it is float that means it is unused. 1 4 v cc input of power supply.
uic811 cmos ic unisonic technologies co., ltd 3 of 8 www.unisonic.com.tw qw-r502-317.h ? block diagram v cc mr gnd reset reset generator reset threshold 4 3 1 2 ? functional diagram v th t rst reset timing diagram t rst v cc mr reset
uic811 cmos ic unisonic technologies co., ltd 4 of 8 www.unisonic.com.tw qw-r502-317.h ? absolute maximum rating parameter symbol ratings unit input voltage v cc -0.3~+6.0 v input current (v cc , mr ) i in 20 ma output current ( reset ) i out 20 ma rate of rise v cc ( rr ) 100 v/s power dissipation (t a =+70c) sot-143 p d 320 mw sot-23/ sot-23-3 300 operating temperature t opr -40~+105 c storage temperature t stg -65~+150 c note: 1. absolute maximum ratings are those values beyo nd which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device oper ation is not implied. 2. the device is not guaranteed to function outside its operating rating. ? electrical characteristics uic811-a (2.63v) (v cc =3v, t a = 25 c , unless otherwise specified) parameter symbol test conditions min typ max unit operating voltage range v cc t a =-40~+85c 1 6 v supply current i cc v cc =3.0v, no load 5 10 a reset voltage threshold v th 2.55 2.63 2.70 v reset timeout period t rst 140 240 560 ms reset output voltage v oh i source =500a 2.4 v v ol v cc = v th min, i sink =1.2ma 0.3 v v cc > 1v, i sink =50a, t a =-40~+85c 0.3 v mr input threshold v ih 2.1 v v il 0.75 v mr minimum pulse width 10 s mr to reset delay 0.5 s mr pull-up resistance 10 20 30 k ? mr glitch immunity 100 ns uic811-b (2.93v) (v cc =3.3v, t a = 25 c , unless otherwise specified) parameter symbol test conditions min typ max unit operating voltage range v cc t a =-40~+85c 1 6 v supply current i cc v cc =3.3v, no load 5 10 a reset voltage threshold v th 2.85 2.93 3.00 v reset timeout period t rst 140 240 560 ms reset output voltage v oh i source =500a 2.64 v v ol v cc = v th min, i sink =1.2ma 0.3 v v cc > 1v, i sink =50a, t a =-40~+85c 0.3 v mr input threshold v ih 2.31 v v il 0.825 v mr minimum pulse width 10 s mr to reset delay 0.5 s mr pull-up resistance 10 20 30 k ? mr glitch immunity 100 ns
uic811 cmos ic unisonic technologies co., ltd 5 of 8 www.unisonic.com.tw qw-r502-317.h ? electrical characteristics(cont.) uic811-c (3.08v) (v cc =3.3v, t a = 25 c , unless otherwise specified) parameter symbol test conditions min typ max unit operating voltage range v cc t a =-40~+85c 1 6 v supply current i cc v cc =3.3v, no load 5 10 a reset voltage threshold v th 3.00 3.08 3.15 v reset timeout period t rst 140 240 560 ms reset output voltage v oh i source =500a 2.64 v v ol v cc = v th min, i sink =1.2ma 0.3 v v cc > 1v, i sink =50a, t a =-40~+85c 0.3 v mr input threshold v ih 2.31 v v il 0.825 v mr minimum pulse width 10 s mr to reset delay 0.5 s mr pull-up resistance 10 20 30 k ? mr glitch immunity 100 ns uic811-d (4.00v) (v cc =5v, t a = 25 c , unless otherwise specified) parameter symbol test conditions min typ max unit operating voltage range v cc t a =-40~+85c 1 6 v supply current i cc v cc =5.0v, no load 5 15 a reset voltage threshold v th 3.89 4.00 4.10 v reset timeout period t rst 140 240 560 ms reset output voltage v oh i source =800a 3.5 v v ol v cc = v th min, i sink =3.2ma 0.4 v v cc > 1v, i sink =50a, t a =-40~+85c 0.3 v mr input threshold v ih 2.3 v v il 0.8 v mr minimum pulse width 10 s mr to reset delay 0.5 s mr pull-up resistance 10 20 30 k ? mr glitch immunity 100 ns uic811-e (4.38v) (v cc =5v, t a = 25 c , unless otherwise specified) parameter symbol test conditions min typ max unit operating voltage range v cc t a =-40~+85c 1 6 v supply current i cc v cc =5.0v, no load 5 15 a reset voltage threshold v th 4.25 4.38 4.50 v reset timeout period t rst 140 240 560 ms reset output voltage v oh i source =800a 3.5 v v ol v cc = v th min, i sink =3.2ma 0.4 v v cc > 1v, i sink =50a, t a =-40~+85c 0.3 v mr input threshold v ih 2.3 v v il 0.8 v mr minimum pulse width 10 s mr to reset delay 0.5 s mr pull-up resistance 10 20 30 k ? mr glitch immunity 100 ns
uic811 cmos ic unisonic technologies co., ltd 6 of 8 www.unisonic.com.tw qw-r502-317.h ? electrical characteristics(cont.) uic811-f (5.0v) (v cc =5.5v, t a = 25 c , unless otherwise specified) parameter symbol test conditions min typ max unit operating voltage range v cc t a =-40~+85c 1 6 v supply current i cc v cc =5.0v, no load 25 a reset voltage threshold v th 4.85 5 5.15 v reset timeout period t rst 140 240 560 ms reset output voltage v oh i source =800a 4.55 v v ol v cc = v th min, i sink =3.2ma 0.4 v v cc >1v, i sink =50a, t a =-40~+85c 0.3 v mr input threshold v ih 2.45 v v il 0.8 v mr minimum pulse width 10 s mr to reset delay 0.5 s mr pull-up resistance 10 20 30 k ? mr glitch immunity 100 ns
uic811 cmos ic unisonic technologies co., ltd 7 of 8 www.unisonic.com.tw qw-r502-317.h ? typical application circuit utc uic811 v cc reset mr p v cc reset v cc ? application information microprocessor reset as soon as v cc falls below the reset threshold voltage, the reset pin is asserted. but the reset pin can keep asserted for a period of 140ms after v cc rose above the reset threshold voltage. after a power failure the reset operation can keep the processor being reset and powers up properly. v cc transients the utc uic811 series won?t cause a reset typically as this situation: a negative-goi ng transient 125mv below the reset threshold with a duration of 20s or less. interfacing to bidirectional reset pins connecting a 4.7k ? resistor in series with the utc uic811 series output and the p reset pin can make the utc uic811 series interface with ps with bidirectional reset pins. reset valid at low voltage as the figure below, adding a resistor which is recommended 100k ? can ensure the reset output remains low with v cc down to 0v. the size of the resistor should be not too large which will load the output excessively and not too small which can pull-down any stray leakage currents.
uic811 cmos ic unisonic technologies co., ltd 8 of 8 www.unisonic.com.tw qw-r502-317.h ? typical characteristics reset timeout out period reset timeout out period mr to reset delay utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. ch1 mr ch2 reset ch1 v cc ch2 reset ch1 mr ch2 reset
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