issue 2 - march 2000 zxcm209 zxcm210 description the zxcm209/210 are three terminal supervisory circuits used to monitor the power supplies in microprocessor and digital systems. they provide a high performance economical solution when used with 5v, 3v or lower powered circuits. reset thresholds suitable for operation with a variety of supply voltages are available. these devices provide a reset signal whenever the supply voltage falls below a preset threshold, keeping it asserted for a minimum delay period of 140ms after the supply has risen above the reset level. the zxcm209 has an active-low reset output (which is guaranteed to be in the correct state for supplies down to 1v), while the zxcm210 has an active-high reset output. the reset comparator has in built hysteresis to prevent erratic operation and is designed to ignore supply transients. low supply current (typically 2a) makes the zxcm209/210 devices ideal for use in portable equipment. they are available in a 3-pin sot23 surface mount package with an industry standard pinout. features ? enhanced alternative to max809/810 and similar parts ? precision monitoring of 5v, 3.3v, 3v power supply voltages ? 1% threshold tolerance ? 2a typical supply current ? 140ms minimum power on reset pulse width ? alternative minimum pulse widths available, contact your local sales office for availability ? reset low output (zxcm209) ? reset high output (zxcm210) ? power supply transient immunity ? no latch up ? no external components ? 3-pin sot23 package applications ? computer systems ? controllers ? instrumentation ? microprocessor power monitoring ? microcontroller power monitoring ? power supplies ? portable/battery-powered equipment ? automotive very low power microprocessor reset devices application circuit v cc zxcm reset output gnd v cc v cc micro reset input gnd 1
zxcm209 zxcm210 absolute maximum ratings terminal voltage with respect to g nd v cc -0.3v to 7.0v reset, reset -0.3v to (v cc + 0.3v) input current, v cc 20ma output current 20ma rate of rise, v cc 250v/s continuous power dissipation 500mw operating temperature range -55c to +125c storage temperature range -65c to +150c stresses beyond those listed under ?absolute maximum ratings? may cause permanent damage to the device. these are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum conditions for extended periods may affect device reliability. electrical characteristics test conditions (unless otherwise stated) v cc = full range, t a = -55c to +125c symbol parameter conditions limits units min typ max v r v cc range t a =0 to 70c t a =-55 to 125c 1.0 1.2 5.5 5.5 v v i cc supply current 2 5 a v th reset threshold suffix l; t a =25c 4.58 4.63 4.68 v suffix m; t a =25c 4.34 4.38 4.42 v suffix j; t a =25c 3.96 4.00 4.04 v suffix t; t a =25c 3.05 3.08 3.11 v suffix s; t a =25c 2.90 2.93 2.96 v suffix r; t a =25c 2.60 2.63 2.66 v v tht reset threshold tolerance t a =25c t a =-55 to 125c 1 5 % % ? v th /c reset threshold temp. coefficient 50 ppm/c v d v cc to reset delay 30 s v to reset active timeout period 140 560 ms 2 issue 2 - march 2000
issue 2 - march 2000 zxcm209 zxcm210 electrical characteristics zxcm209 test conditions (unless otherwise stated) v cc = full range, t a = -55c to +125c symbol parameter conditions limits units min typ max v ol reset output voltage low v cc >1v, i ol =100a (0 to 85c) 0.3 v v cc >1.2v, i ol =200a 0.3 v v th >v cc >2.5v, i ol =2.7ma 0.4 v v oh reset output voltage high v cc >v th max, i oh =1ma 0.8v cc v electrical characteristics zxcm210 test conditions (unless otherwise stated) v cc = full range, t a = -55c to +125c symbol parameter conditions limits units min typ max v ol reset output voltage low v cc >v th max, i ol =2ma 0.3 v v cc >v th max, i ol =2.7ma 0.4 v v oh reset output voltage high v cc >1.5v, i oh =150a 0.8v cc v v th >v cc >2.5v, i oh =1ma 0.8v cc v note: device testing is performed at t a =25c. device thermal performance is guaranteed by design typical characteristics 3
issue 2 - march 2000 zxcm209 zxcm210 typical characteristics 4
issue 2 - march 2000 zxcm209 zxcm210 applications information negative going v cc transients the zxcm209/210 are, to a good degree, immune to short duration negative going supply transients. under certain circumstances very brief transients are allowed without inappropriate false triggering of the reset circuit. the response to supply transients is shown in the noise immunity graph in the typical characteristics. the graph indicates the typical allowable transient duration for a specified threshold overdrive such that a reset pulse is not generated. addition of a bypass capacitor, e.g. 0.1f, as close as possible to the v cc pin will provide extra transient immunity. reset valid down to very low supply voltages with v cc between 0v and 1v the output of the zxcm209/210 may be in an undefined state. in many systems this is inconsequential as the microprocessor, and other circuits, will be inoperative with supplies this low. in applications where this is important, the addition of an external resistor ensures that the reset output remains valid for v cc < 1v. the resistor value is non critical: a value of 100k ? is recommended. for the zxcm209 the resistor should be applied between reset output and ground: for the zxcm210 between reset output and v cc . figure 1 shows the connection diagram for the zxcm devices in these configurations. v cc zxcm210 reset output gnd v cc micro reset input gnd v cc 100k v cc zxcm209 reset output gnd v cc micro reset input gnd v cc 100k figure 1 circuit for operation of zxcm with reset valid down to very low supply voltage. 5
issue 2 - march 2000 zxcm209 zxcm210 v cc zxcm reset output gnd v cc micro reset input gnd v cc 4.7k ? to other circuits interfacing to p?s with bidirectional reset i/o the zxcm series can be used with microprocessors havng bidirectional reset pins, such as motorola 68hc11 series. the addition of a 4.7k resistor between the zxcm reset output and the processor input ensures correct operation of the reset circuit. a buffer to other circuit components is then required to enable the processor reset drive to operate correctly. the circuit configuration is shown in figure 2. pin description pin number pin name pin function 1v cc supply voltage (+5, +3.3, +3 volts) 2 reset (zxcm209) reset (zxcm210) output remains low while vcc is below the reset threshold, and for a minimum 140ms after v cc rises above the reset threshold. output remains high while v cc is below the reset threshold, and for a minimum 140ms after v cc rises above the reset threshold. 3 gnd ground 1 2 3 figure 2 interfacing to p?s with bidirectional reset i/o. 6
issue 2 - march 2000 zxcm209 zxcm210 ordering information part number temperature range package reset output zxcm209xf -55 to 125c sot23 low zxcm210xf -55 to 125c sot23 high x=insert appropriate threshold voltage code. zxcm209 threshold voltage codes part mark threshold code reset threshold (v) m22 l 4.63 m23 m 4.38 m24 j 4.00 m25 t 3.08 m26 s 2.93 m27 r 2.63 zxcm210 threshold voltage codes part mark threshold code reset threshold (v) m28 l 4.63 m29 m 4.38 m30 j 4.00 m31 t 3.08 m32 s 2.93 m33 r 2.63 7
issue 2 - march 2000 zxcm209 zxcm210 n package dimensions pad layout details dim millimetres inches min max min max a 2.67 3.05 0.105 0.120 b 1.20 1.40 0.047 0.055 c ? 1.10 ? 0.043 d 0.37 0.53 0.0145 0.021 f 0.085 0.15 0.0033 0.0059 g nom 1.9 nom 0.075 k 0.01 0.10 0.0004 0.004 l 2.10 2.50 0.0825 0.0985 n nom 0.95 nom 0.037 8 zetex plc. fields new road, chadderton, oldham, ol9-8np, united kingdom. telephone: (44)161 622 4422 (sales), (44)161 622 4444 (general enquiries) fax: (44)161 622 4420 zetex gmbh zetex inc. zetex (asia) ltd. these are supported by streitfeldstra?e 19 47 mall drive, unit 4 3510 metroplaza, tower 2 agents and distributors in d-81673 mnchen commack ny 11725 hing fong road, major countries world-wide germany usa kwai fong, hong kong ? zetex plc 2000 telefon: (49) 89 45 49 49 0 telephone: (631) 543-7100 telephone:(852) 26100 611 fax: (49) 89 45 49 49 49 fax: (631) 864-7630 fax: (852) 24250 494 internet :http://www.zetex.com this publication is issued to provide outline information only which (unless agreed by the company in writing) may not be used, applied or reproduced f or any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. the company reserve s the right to alter without notice the specification, design, price or conditions of supply of any product or service.
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