ap1701/2/3/4 3-pin microprocessor reset circuits this datasheet contains new product information. anachip corp. re serves the rights to modify the product specification without notice. no liability is assumed as a result of the use of this product. no rights under any patent accompany the sale of the product. rev. 1.4 nov. 10, 2005 1/9 ? features - precision monitoring of +2.5v, +3v, +3.3v, and +5v power-supply voltages - fully specified over temperature - available in three output configurations - push-pull reset low output (ap1701/3) - push-pull reset high output (ap1702/4) - 200ms min power-on reset pulse width - 20a supply current (typ.) - guaranteed reset valid to vcc = +1v - power supply transient immunity - no external components - 3-pin sot23, tsot23, pb-free package ? applications - computers - controllers - intelligent instruments - critical p and c power monitoring - portable/battery powered equipment - automotive ? general description the ap1701/2/3/4 are 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 external components and adjustments when used with +5v, +3.3v, +3.0v 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 240ms after vcc has risen above the reset threshold. reset thresholds suitable for operation with a variety of supply voltages are available. the ap1701/2/3/4 have push pull outputs. the ap1701/3 have an active low reset output, while the ap1702/4 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 1v. low supply current makes the ap1701/2/3/4 ideal for use in portable equipment. the ap1701/2/3/4 is available in a 3-pin sot23,tsot23 package. ? pin assignments (top view) 1 2 gnd (reset) v cc sot-23/tsot23 ap1701 ap1702 2 3 reset (top view) 1 2 gnd v cc sot-23/tsot23 ap1703 ap1704 2 3 (reset) reset ? pin descriptions name description gnd ground reset (reset) reset output pin l: for ap1701/3 h: for ap1702/4 v cc operating voltage input
ap1701/2/3/4 3-pin microprocessor reset circuits this datasheet contains new product information. anachip corp. re serves the rights to modify the product specification without notice. no liability is assumed as a result of the use of this product. no rights under any patent accompany the sale of the product. rev. 1.4 nov. 10, 2005 2/9 ? ordering information ap170x x x enable 1: active-low 2: active-high voltage a: 4.63 b: 4.38 c: 4.00 d: 3.08 e: 2.93 f: 2.63 g: 2.25 3: active-low 4: active-high package w:sot23 tw:tsot23 ? absolute maximum ratings symbol parameter rating unit v cc terminal voltage (with respect to gnd) -0.3 to +6.0 v v reset reset, reset (push-pull) -0.3 to (v cc + 0.3) v i cc input current, v cc 20 ma i o output current, reset, reset 20 ma p d continuous power dissipation (t a = +70c), de-rate 4mw/c above +70c 320 mw t op operating temperature range -40 to +105 c t st storage temperature range -65 to +150 c t lead lead temperature (soldering, 10s) +300 c
ap1701/2/3/4 3-pin microprocessor reset circuits anachip corp. www.anachip.com.tw rev. 1.4 nov. 10, 2005 3/9 ? electrical characteristics (t a =25oc) symbol parameter conditions min. typ. max. unit v cc v cc range t a = 0 o c to +70 o c 1.0 5.5 v i cc supply current v th +1.0v 20 30 a ap1701/2/3/4a 4.54 4.63 4.72 ap1701/2/3/4b 4.29 4.38 4.47 ap1701/2/3/4c 3.92 4.00 4.08 ap1701/2/3/4d 3.02 3.08 3.14 ap1701/2/3/4e 2.87 2.93 2.99 ap1701/2/3/4f 2.57 2.63 2.68 reset threshold t a =25oc ap1701/2/3/4g 2.20 2.25 2.30 v v th reset threshold te m p c o 30 ppm/ o c t s set-up time v cc = 0 to (v th ? 100mv) 100 s t delay reset active timeout period t a = 0 o c to +70 o c 100 240 600 ms v cc = v th min, i sink = 1.2ma, ap1701/3 0.3 v cc = v th min, i sink = 3.2ma 0.4 v ol t rese output voltage low v cc > 1.0v, i sink = 50ua 0.3 v v cc > v th max, i source = 500ua, ap1701/3 0.8v cc v oh t rese output voltage-high v cc > v th max, i source = 800ua v cc ?1.5 v v cc = v th max, i sink = 1.2ma, ap1702/4 0.3 v ol reset output voltage-low v cc = v th max, i sink = 3.2ma 0.4 v v oh reset output voltage-high 1.8v < v cc < v th min, i source = 150ua, ap1702/4 0.8 v cc v ? application circuit ap170x gnd reset (reset) vcc microprocessor vcc gnd reset input vcc
ap1701/2/3/4 3-pin microprocessor reset circuits anachip corp. www.anachip.com.tw rev. 1.4 nov. 10, 2005 4/9 ? function description a microprocessor?s (p?s) reset input starts the p in a known state. the ap1701/2/3/4 assert 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 240ms after vcc has risen above the reset threshold. the ap1701/2/3/4 have a push-pull output stage. applications information negative-going vcc transients in addition to issuing a reset to the p during power-up, power-down, and brownout conditions, the ap1701/2/3/4 are relatively immune to short-duration negative-going vcc transients (glitches). the ap1701/2/3/4 do 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 100mv below the reset threshold and lasts 100s or less will not cause a reset pulse. a 0.1f bypass capacitor mounted as close as possible to the vcc pin provides additional transient immunity. ensuring a valid reset output down to vcc = 0 reset is guaranteed to be a logic low for vcc > 1v. once vcc exceeds the reset threshold, an internal timer keeps reset low for the reset timeout period; after this interval, reset goes high. if a brownout condition occurs (vcc dips below the reset threshold), reset goes low. any time vcc goes below the reset threshold, the internal timer resets to zero, and reset goes low. the internal timer starts after vcc returns above the reset threshold, and reset remains low for the reset timeout period. when vcc falls below 1v, the ap1701/3 reset output no longer sinks current?it becomes an open circuit. therefore, hi gh-impedance cmos logic inputs connected to reset can drift to undetermined voltages. this presents no problem in most applications since most p and other circuitry is inoperative with vcc below 1v. however, in applications where reset must be valid down to 0v, adding a pull down resistor to reset causes any stray leakage currents to flow to ground, holding reset low. r1?s value is not critical; 100k is large enough not to load reset and small enough to pull reset to ground. for the ap1702/4 if reset is required to remain valid for vcc < 1v. benefits of highly ac curate reset threshold most p supervisor ics have 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.
ap1701/2/3/4 3-pin microprocessor reset circuits anachip corp. www.anachip.com.tw rev. 1.4 nov. 10, 2005 5/8 ? function block v ref delay circuit driver reset / reset ? performance characteristics -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 iq 24 20 16 12 8 4 0 temp ( c ) iq v.s temp -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 threshold temp 2.92 2.922 2.924 2.926 2.928 threshold v.s. temp
ap1701/2/3/4 3-pin microprocessor reset circuits anachip corp. www.anachip.com.tw rev. 1.4 nov. 10, 2005 6/9 ? timing diagram t s 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) t delay v cc v th active low active high t delay t delay t delay
ap1701/2/3/4 3-pin microprocessor reset circuits anachip corp. www.anachip.com.tw rev. 1.4 nov. 10, 2005 7/9 ? marking information 1 2 3 xx y m x (top view) sot23-3l/tsot23-3l xx : identification code (see appendix) y : year: 0-9 m : month: a~l appendix part number identification code part number identification code ap1701a ea ap1703a eg ap1701b eb ap1703b eh ap1701c ec ap1703c ei ap1701d ed ap1703d ej ap1701e ee ap1703e ek ap1701f ef ap1703f el ap1701g w1 ap1703g w3 ap1702a e0 ap1704a e7 ap1702b e2 ap1704b e8 ap1702c e3 ap1704c e9 ap1702d e4 ap1704d em ap1702e e5 ap1704e en ap1702f e6 ap1704f ep ap1702g w2 ap1704g w4
ap1701/2/3/4 3-pin microprocessor reset circuits anachip corp. www.anachip.com.tw rev. 1.4 nov. 10, 2005 8/9 ? package information (1) package type: sot23-3l c l e e he d a2 a1 b a dimensions in millimeters dimensions in inches symbol min. nom. max. min. nom. max. a 1.00 1.20 1.40 0.039 0.047 0.055 a1 0.00 - 0.10 0.000 - 0.004 a2 1.00 1.15 1.30 0.039 0.045 0.051 b 0.35 - 0.50 0.014 - 0.020 c 0.10 0.175 0.25 0.004 0.007 0.010 d 2.70 2.90 3.10 0.106 0.114 0.122 e 1.40 1.60 1.80 0.055 0.063 0.071 e 1.70 2.00 2.30 0.067 0.079 0.091 he 2.40 2.70 3.00 0.094 0.106 0.118 l 0.30 - 0.55 0.012 - 0.022
ap1701/2/3/4 3-pin microprocessor reset circuits anachip corp. www.anachip.com.tw rev. 1.4 nov. 10, 2005 9/9 ? package information (continued) (2) package type: tsot23-3l e1 e e e1 b d a a1 a2 y 2 4x 1 l1 r l c l2 gauge plane dimensions in millimeters dimensions in inches symbol min. nom. max. min. nom. max. a 0.75 - 0.90 0.030 - 0.035 a1 0.00 - 0.10 0.000 - 0.004 a2 0.70 0.75 0.80 0.028 0.030 0.031 b 0.35 - 0.51 0.014 - 0.020 c 0.10 - 0.25 0.004 - 0.010 d 2.80 2.90 3.00 0.110 0.114 0.118 e 2.60 2.80 3.00 0.102 0.110 0.118 e1 1.50 1.60 1.70 0.059 0.063 0.067 e 0.95 bsc. 0.037 e1 1.90 bsc. 0.075 l 0.37 - - 0.015 - - l1 0.60 ref. 0.024 l2 0.25 bsc. 0.010 y - - 0.10 - - 0.004 r 0.10 - - 0.004 - - 0 o - 8 o 0 o - 8 o 1 7 o nom. 7 o nom. 2 5 o nom. 5 o nom.
|
