1/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 3 - pin microprocessor reset circuits ? general description the ax6905/6 is used for microprocessor ( p ) supervisory circuits to monitor the power supplies in p and digital systems. they provide excellent circuit reliability and low cost by eliminating exte rnal components and adjustments when used with +5v, +3.3v, +3.0v , +2.5v powered circuits. these circuits perform a single function: they assert a reset signal whenever the vcc supply voltage declines below a preset threshold, keeping it asserted for at least 200ms after vcc has risen above the reset threshold. reset thresholds suitable for operation with a variety of supply voltages are available. the ax6905/6 has push pull outputs. the ax6905 have an active low r eset output, while the AX6906 has an active high reset output. the reset comparator is designed to ignore fast transients on vcc, and the outputs are guaranteed to be in the correct logic state for vcc down to 1.0v. low supply current makes the ax6905/6 ideal for use in portable equipment. the ax6905/6 is available in a 3-pin sot- 23 and sc70 package. ? features - precision monitoring of +2.5, +3v, +3.3v, and +5v power - supply voltages - fully specified over temperature - available in three output configurations - push - pull r eset low output (ax690 5 ) - push - pull reset high output (ax690 6 ) - 200ms (typ.)min power - on reset pulse width - 2 5a supply current - guaranteed reset valid to vcc = + 1.0 v - power supply transient immunity - no external components - available in the 3 - pin pb - free sot - 23 and s c70 package v?mw`r?y?b? w w w . g o f o t e c h . c o m
2/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 ? block diagram ? pin assignment the packages of ax6905/6 are sot - 23- 3l and sc70 - 3l ; the pin assignment is given by : name description gnd ground (reset ) reset output pin l: forax6905 h: forAX6906 v cc operating voltage input ? order/marking information order information top marking vref delay circuit reset / reset gnd vcc + - p - mos n - mos ( t o p v i e w ) 1 2 g n d v c c s o t - 2 3 - 3 l / s c 7 0 - 3 l a x 6 9 0 5 a x 6 9 0 6 2 3 ( r e s e t ) r e s e t reset a x 6 9 0 x x x x e n a b l e 5 : a c t i v e - l o w 6 : a c t i v e - h i g h v o l t a g e a : 4 . 6 3 b : 4 . 3 8 c : 4 . 0 0 d : 3 . 0 8 e : 2 . 9 3 f : 2 . 6 3 g : 2 . 2 5 h : 2 . 7 0 i : 4 . 2 5 p a c k a g e r : s o t - 2 3 - 3 l b l a n k : b a g p a c k i n g a : s c 7 0 - 3 l a : t a p i n g l i d e n t i f i c a t i o n c o d e w w : 0 1 ~ 2 6 ( a ~ z ) 2 7 ~ 5 2 ( a ~ z ) y e a r : a = 2 0 1 0 1 = 2 0 1 1 l y w i d c o d e : i n t e r n a l x l i d e n t i f i c a t i o n c o d e w w : 0 1 ~ 2 6 ( a ~ z ) 2 7 ~ 5 2 ( a ~ z ) y e a r : a = 2 0 1 0 1 = 2 0 1 1 l y w i d c o d e : i n t e r n a l v?mw`r?y?b? w w w . g o f o t e c h . c o m
3/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 appendix part number package identification code part number package identification code ax69 0 5 a sot23 - 3l sa ax690 5 a sc70 - 3l sq ax69 0 5 b sot23 - 3l sb ax690 5 b sc70 - 3l sr ax690 5 c sot23 - 3l sc ax690 5 c sc70 - 3l ss ax690 5 d sot23 - 3l sd ax690 5 d sc70 - 3l st ax690 5 e sot23 - 3l se ax690 5 e sc70 - 3l su ax690 5 f sot23 - 3l sf ax690 5 f sc70 - 3l sv ax690 5 g sot23 - 3l sg ax690 5 g sc70 - 3l sw ax690 5h sot23 - 3l sa ax690 5h sc70 - 3l sc ax690 5i sot23 - 3l sb ax690 5i sc70 - 3l sd ax690 6 a sot23 - 3l sh ax690 6 a sc70 - 3l sx ax690 6 b sot23 - 3l si ax690 6 b sc70 - 3l sy ax690 6 c sot23 - 3l sj ax690 6 c sc70 - 3l sz ax690 6 d sot23 - 3l sk ax690 6 d sc70 - 3l s2 ax690 6 e sot23 - 3l sl ax690 6 e sc70 - 3l s3 ax690 6 f sot23 - 3l so ax690 6 f sc70 - 3l s4 ax690 6 g sot23 - 3l sp ax690 6 g sc70 - 3l s5 ax690 6h sot23 - 3l se ax690 6h sc70 - 3l sg ax690 6i sot23 - 3l sf ax690 6i sc70 - 3l sh ? absolute maximum ratings ( at t a =25 c ) characteristics symbol rating unit vcc pin voltage v cc gnd - 0.3 to gnd + 6 .5 v reset, (push - pull) pin voltage v reset gnd - 0.3 to v cc + 0.3 v input current, v cc i cc 20 ma output current, reset, i o 5 ma power dissipation pd ( t j - t a ) / ja mw storage tempera ture range t st - 6 0 to +150 c operating temperature range t op - 4 0 to + 8 5 c junction temperature t j - 4 0 to + 150 c thermal resistance from junction to case jc 110 c /w thermal resistance from junction to ambient ja 25 0 c /w note : ja is measured w ith the pcb copper area of approximately 1 in 2 (multi - layer). t hat need connect to v ss pin . reset v?mw`r?y?b? w w w . g o f o t e c h . c o m
4/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 ? electrical characteristics t a =25 c (unless otherwise noted) characteristics symbol conditions min typ max units operating v cc range v range 1. 0 - 6 v supp ly current i cc v cc = v th +1.0v - 25 35 a reset threshold t a =25oc v th ax6905/6 a 4.54 4.63 4.71 v ax6905/6 b 4.29 4.38 4.46 ax6905/6i 4.16 4.25 4.33 ax6905/6 c 3.92 4.00 4.08 ax6905/6 d 3.02 3.08 3.15 ax6905/6 e 2.87 2.93 3.00 ax6905/6h 2.64 2.70 2.75 ax6905/6 f 2.57 2.63 2.69 ax6905/6 g 2.20 2.25 2.30 reset threshold tempco v th t t a = 0 o c to + 85 c - 50 - ppm/ o c set - up time t s v cc = 0 to (v th C 100mv) 1 - - s v cc to reset delay t rd v cc =v th to (v th - 100mv) - 20 - s reset active timeout period t delay t a = 0 o c to + 85 c 140 200 260 ms output voltage ( ax690 5 ) v ol 1.8v< v cc < v th ( min ) , i sink = 1.2ma - - 0.3 v 1.2 v < v cc < 1.8 v, i sink = 50ua v oh v cc > v th ( max ) , i source = 500ua, 0.8v cc - - v reset output voltage ( ax690 6 ) v ol v cc > v th ( m ax ) , i sink = 1.2ma, - - 0.3 v v oh 1.8v < v cc < v th ( min ) , i source = 500 ua 0.8 v cc - - v 1. 2 v < v cc < 1.8v , i source = 150ua hysteresis at v cc v h ys i nput voltage - 4 0 - mv ? application circuit t rese ax 6905 / 6 gnd reset ( reset ) vcc microprocessor vcc gnd reset input vcc v?mw`r?y?b? w w w . g o f o t e c h . c o m
5/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 ? function descriptio ns a microprocessors ( ps) reset input starts the p in a known state. the ax6905/6 asserts reset to prevent code-execution errors during power-up, power-down, or brownout conditions. they assert a reset signal whenever the vcc supply voltage declines below a preset threshold, keeping it asserted for at least 200ms after vcc has risen above the reset threshold. the ax6905/6 has a push-pull output stage. ? application information negative - going vcc transients in addition to issuing a reset to the p during power - up, power - down, and brownout conditions, the ax6905/6 is relatively immune to short - duration negative - going vcc transients (glitches). the ax6905/6 does not generate a reset pulse. the graph was generated using a negative going pulse applied to vcc, starting 0.5v above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). the graph indicates the maximum pulse width a negative going vcc transient can have without causing a reset pulse. as the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. typically, a vcc transient that goes 50mv below the reset threshold a 0.1f bypass capacitor mounted as close as possible to the vcc pin prov ides additional transient immunity. ensuring a valid reset output down to vcc = 0 is guaranteed to be a logic low for vcc > 1 . 0 v. once vcc exceeds the reset threshold, an internal timer keeps low for the rese t timeout period; after this interval, goes high. if a brownout condition occurs (vcc dips below the reset threshold), goes low. any time vcc goes below the reset threshold, the internal timer resets to zero, and goes low. the internal timer starts after vcc returns above the reset threshold, and remains low for the reset timeout period. when vcc falls below 1 . 0 v, the ax69 0 5 reset output no longer sinks current i t becomes an open circuit. therefore, high - impedance cmos logic inputs connected to can drift to undetermined voltages. this presents no problem in most applications since most p and other circuitry is inoperative with vcc below 1 . 0 v . however, in applications where must be valid down to 0v, adding a pull down resistor to causes any stray leakage currents to flow to ground, holding low. r1s value is not critical; 100 k is large enough not to load and small enough to pull to ground. for the ax69 0 6 if reset is required to remain valid for vcc < 1 . 0 v. reset v?mw`r?y?b? w w w . g o f o t e c h . c o m
6/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 benefits of highly accurate reset threshold most p supervisor ics h as reset threshold voltages between 5% and 10% below the value of nominal sup-ply voltages. this ensures a reset will not occur within 5% of the nominal supply, but will occur when the supply is 10% below nominal. when using ics rated at only the nominal supply 5%, this leaves a zone of uncertainty where the supply is between 5% and 10% low, and where the reset may or may not be asserted. v?mw`r?y?b? w w w . g o f o t e c h . c o m
7/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 ? t ypical c haracteristics 2.9 2.91 2.92 2.93 2.94 2.95 2.96 -50 -25 0 25 50 75 100 threshold voltage (v) ?? ???3?:? temperature vs threshold voltage v th =2.93v 150 160 170 180 190 200 210 220 230 240 250 -50 -25 0 25 50 75 100 reset active timeout period (ms) ?? ???3?:? temperature vs reset active timeout period 20 22 24 26 28 30 32 34 -50 -25 0 25 50 75 100 reset acsupply current (ua) ?? ???3?:? temperature vs supply current v th =2.93v 20 22 24 26 28 30 32 34 2.25 2.63 2.93 3.08 4 4.38 4.63 supply current (ua) threshold voltage (v) threshold voltage vs supply current v cc =v th +1v 0 5 10 15 20 25 30 35 40 45 50 -50 -25 0 25 50 75 100 temperature vs power-down reset delay power-down reset delay (us) ?? ???3?:? v th =2.25v v od =v th -v cc v od =50mv v od =100mv v od =200mv 0 5 10 15 20 25 30 35 40 45 50 -50 -25 0 25 50 75 100 temperature vs power-down reset delay power-down reset delay (us) ?? ???3?:? v th =2.93v v od =v th -v cc v od =100mv v od =50mv v od =200mv 0 10 20 30 40 50 60 70 80 90 100 -50 -25 0 25 50 75 100 temperature vs power-down reset delay power-down reset delay (us) ?? ???3?:? v th =4.63v v od =v th -v cc v od =50mv v od =200mv v od =100mv v?mw`r?y?b? w w w . g o f o t e c h . c o m
8/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 ? t iming d iagram giltch immunity 3000 900 270 140 90 70 58 50 50 48 48 0 500 1000 1500 2000 2500 3000 3500 0 100 200 300 400 500 600 700 800 900 1000 1100 reset comparator overdrive(mv) maximum transient duration(us) v?mw`r?y?b? w w w . g o f o t e c h . c o m
9/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 ? package outlines (1) sot - 23- 3l symbol dimensions in millimeters dimensions in inches min. nom. max. min. nom. max. a - - 1.45 - - 0.057 a1 0.00 0.08 0.15 - - 0.006 a2 0.90 1.10 1.30 0.035 0.043 0.051 b 0.30 0.40 0.50 0.012 0.016 0.020 c 0.08 0.15 0.22 0.003 0.006 0.009 d 2.70 2.90 3.10 0.106 0.114 0.122 e 2.60 2.80 3.00 0.102 0.110 0.118 e1 1.40 1.60 1.80 0.055 0.063 0.071 l 0.30 0.45 0.60 0.012 0.018 0.024 l1 0.50 0.60 0.70 0.020 0.024 0.028 e 1.9 bsc 0.07 5 bsc e1 0.95 bsc 0.037 bsc 0 o 4 o 8 o 0 o 4 o 8 o jedec outline: na l e e 1 e d a 2 a 1 b a view c l 1 e 1 gauge plane c see view c v?mw`r?y?b? w w w . g o f o t e c h . c o m
10/ 10 axelite confidential materials, do not copy or distribute without written consent. rev. 1.2 jul.30, 2010 ax6905/6 (2) sc70 - 3l symbol dimensions in millimeters dimensions in inches min. nom. max. min. nom. max. a 0.80 0.95 1.10 0.031 0.037 0.043 a1 0.00 0.05 0.10 0.000 0.002 0.004 a2 0.70 0.90 1.00 0.028 0.035 0.039 b 0.20 0.30 0.40 0.008 0.012 0.016 c 0.08 0.15 0.22 0.003 0.006 0.009 d 1.80 2.00 2.20 0.071 0.079 0.087 e 1.95 2.20 2.45 0.077 0.087 0.096 e1 1.15 1.25 1.35 0.045 0.049 0.053 e 1.30 bsc 0.051 bsc l 0.26 0.36 0.46 0.010 0.014 0.018 l2 0.15 bsc 0.006 bsc y - - 0.10 - - 0.004 0o 4o 8o 0o 4o 8o 4o - 12o 4o - 12o mold flash shall not exceed 0.15mm per side v?mw`r?y?b? w w w . g o f o t e c h . c o m
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