ver: 1.2 jun 03, 2004 tel: 886-3-5788833 http://www.gmt.com.tw 1 g684/G685 global mixed-mode technology inc. microprocessor reset ic features ? precision monitoring of +3v, +3.3v, and +5v power-supply voltages ? fully specified over temperature ? available in three output configurations push-pull reset output (g684l) push-pull reset output (g684h) open-drain reset output (G685l) ? 14a supply current ? guaranteed reset valid to v cc = 0.8v ? power supply transient immunity ? 5 pin sot23-5 packages ? 2% threshold accuracy applications ? computers ? controllers ? intelligent instruments ? critical p and c power monitoring ? portable / battery-powered equipment ? automotive general description the g684/G685 are microprocessor (p) supervisory circuits used to monitor the power supplies in p and digital systems. they provide excellent circuit reliability and low cost 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 v cc supply voltage declines below a preset threshold, with hysteresis after v cc has risen above the reset threshold. reset thresholds suitable for operation with a variety of supply voltages are available. the G685 has an open-drain output stage, while the g684 have push-pull outputs. the G685l?s open-drain reset output requires a pull-up resistor that can be connected to a voltage higher than v cc . the g684l have an active-low reset output, while the g684h has an active-high reset output. the reset com- parator is designed to ignore fast transients on v cc , and the outputs are guaranteed to be in the correct logic state for v cc down to 0.8v. low supply current makes the g684/G685 ideal for use in portable equipment. the g684/G685 are avail- able in 5-pin sot23-5 packages. ordering information order number temp. range package g684h(l) xxxt1u -40c ~ + 105c sot23-5 G685l xxxt1u -40c ~ + 105c sot23-5 note: t1 : sot23-5 u : tape & reel * xxx specifies the threshold volt age. e.g. 263 denotes the 2.63v threshold voltage. pin configuration typical application circuit sot23-5 g684/G685 5 1 2 reset (reset) n.c. 4 3 gnd ()is for g684h *G685 only reset input gnd p vcc reset (reset) gnd g684/G685 vcc v cc r pull-up* vcc gnd sot23-5 g684/G685 5 1 2 reset (reset) n.c. 4 3 gnd ()is for g684h *G685 only reset input gnd p vcc reset (reset) gnd g684/G685 vcc v cc r pull-up* vcc gnd
ver: 1.2 jun 03, 2004 tel: 886-3-5788833 http://www.gmt.com.tw 2 g684/G685 global mixed-mode technology inc. absolute maximum ratings terminal voltage (with respect to gnd) v cc .???????????..??.??.-0.3v to +6.0v delay capacitor pin voltage, v cd ?..-0.3 to (v cc +0.3v) reset, reset (push-pull)....?....-0.3v to (v cc + 0.3v) reset (open drain)...?......?................-0.3v to +6.0v input current, v cc ............................?..?............20ma output current, reset, reset ......?...............20ma continuous power dissipation (t a = +70c) 5-pin sot23-5 (derate 2.17mw/c above +70c).174mw operating temperature range ?...?..-40c to +105c storage temperature range..?.?......-65c to +150c lead temperature (soldering, 10s)...?...?.?...+260c stresses beyond those listed under ?absolute maximum ratings? may cause permanent damage to the device. these are stress rat- ings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational se ctions of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliab ility. electrical characteristics (v cc = full range, t a = -40c to +105c, unless otherwise noted. typical values are at t a = +25c, v cc = 5v for 463/438/400/330 versions, v cc = 3.3v for 308/293 versions, and v cc = 3v for 263 version.) (note 1) parameter symbol condition min typ max unit t a = 0c +70c 0.8 --- 5.5 v cc range t a = -40c +105c 1 --- 5.5 v v cc <5.5v, g68_ _463/438/400/330_ --- 16.5 25 supply current (sot23-5) i cc v cc <3.6v, g68_ _308/293/263_ --- 13.9 27 a g69_ _463_ 4.50 4.60 4.69 g69_ _438_ 4.23 4.32 4.40 g69_ _400_ 3.88 3.96 4.04 g69_ _330_ 3.25 3.30 3.37 g69_ _308_ 3.04 3.10 3.16 g69_ _293_ 2.86 2.91 2.96 reset threshold v th- g69_ _263_ 2.59 2.64 2.69 v reset threshold hysterisis v hys 3.6 5.3 7 % reset threshold tempco --- 70 --- ppm/c reset time delay v cc from 0v to 5v --- 2 --- ms reset output current low (push-pull active low, and open-drain active-low, g684l and G685l) i ol v cc = 2.5v, v reset = 0.5v 8 --- --- ma v cc = 5v, v reset = 4.5v, g684l463/438/400/330 4.5 --- --- v cc = 3.3v, v reset = 2.8v, g684l308/293 3 --- --- reset output current high (push-pull active low, g684l) i oh v cc = 3v, v reset = 2.5v, g684l263 2 --- --- ma v cc = 5v, v reset = 0.5v, g684h463/438/400/330 16 --- --- v cc = 3.3v, v reset = 0.5v, g684h308/293 12 --- --- reset output current low (push-pull active high, g684h) i ol v cc = 3v, v reset = 0.5v, g684h263 10 --- --- ma reset output current high (push-pull active high, g684h) i oh v cc = 2.5v, v reset = 2v 2 --- --- ma reset open-drain output leak- age current (G685l) v cc > v th , reset deasserted --- --- 1 a note 1: production testing done at t a = +25c; limits over temperature guaranteed by design.
ver: 1.2 jun 03, 2004 tel: 886-3-5788833 http://www.gmt.com.tw 3 g684/G685 global mixed-mode technology inc. selector guide part/suffix reset threshold (v) output type top mark G685l463t1u 4.63 open-drain reset 685gx G685l438t1u 4.38 open-drain reset 685fx G685l400t1u 4.00 open-drain reset 685ex G685l330t1u 3.30 open-drain reset 685dx G685l308t1u 3.08 open-drain reset 685cx G685l293t1u 2.93 open-drain reset 685bx G685l263t1u 2.63 open-drain reset 685ax g684h463t1u 4.63 push-pull reset 684lx g684h438t1u 4.38 push-pull reset 684kx g684h400t1u 4.00 push-pull reset 684jx g684h330t1u 3.30 push-pull reset 684nx g684h308t1u 3.08 push-pull reset 684ix g684h293t1u 2.93 push-pull reset 684hx g684h263t1u 2.63 push-pull reset 684gx g684l463t1u 4.63 push-pull reset 684fx g684l438t1u 4.38 push-pull reset 684ex g684l400t1u 4.00 push-pull reset 684dx g684l330t1u 3.30 push-pull reset 684mx g684l308t1u 3.08 push-pull reset 684cx g684l293t1u 2.93 push-pull reset 684bx g684l263t1u 2.63 push-pull reset 684ax
ver: 1.2 jun 03, 2004 tel: 886-3-5788833 http://www.gmt.com.tw 4 g684/G685 global mixed-mode technology inc. typical operating characteristics (v cc = full range, t a = -40c to +105c, unless otherwise noted. typical values are at t a = +25c, v cc = 5v for 463/438/400/330 versions, v cc = 3.3v for 308/293 versions, and v cc = 3v for 263 version.) functional diagram figure 1 0 1 2 3 4 5 6 7 8 0 0.6 1 1.2 1.5 1.8 2.1 2.4 2.7 3 3.2 3.3 3.4 3.5 3.7 3.9 4 4.5 5 5.5 6 v cc (v) supply current (a) 0.96 0.97 0.98 0.99 1 1.01 1.02 1.03 1.04 1.05 1.06 -40-30-20-10 0 10202730405060708090 t a , ambient temperature (c) normalized ormalized v th+ , v th- (v) 0 1 2 3 4 5 6 7 -40-20 0 20406080 temperature (c) supply current (a) supply current vs. v cc supply curremt vs. temperature (no load) v cc =3.3v v cc =5v v cc =2.5v normalized reset threshold vs. temperature v t v th () is for g684h 5 v cc v th reset 4 2 gnd + r d 5 v cc v th reset (reset) 4 2 gnd + r d * () is for g684h 5 v cc v th reset 4 2 gnd + r d 5 v cc v th reset (reset) 4 2 gnd + r d *
ver: 1.2 jun 03, 2004 tel: 886-3-5788833 http://www.gmt.com.tw 5 g684/G685 global mixed-mode technology inc. pin description pin name function 1 n.c. no connection. 2,3 gnd ground reset (g684l/G685l) reset output remains low while v cc is below the reset threshold, and for 2ms typical after v cc rises above the reset threshold. 4 reset (g684h) reset output remains high while v cc is below the reset threshold, and for 2ms typical after v cc rises above the reset threshold. 5 v cc supply voltage (+5v, +3.3v, +3.0v) detailed description a microprocessor?s (p?s) reset input starts the p in a known state. the G685l/g684l/g684h assert reset to prevent code-execution errors during power-up, power-down, or brownout conditions. they assert a reset signal whenever the v cc supply voltage declines below a preset threshold (v th- ), v cc has risen above the high reset threshold v th+ (v th- +v hys ). the G685l uses an open-drain output, and the g684l/g684h have a push-pull output stage. c onnect a pull-up resistor on the G685l?s reset output to any supply between 0 and 5.5v. ensuring a valid reset output down to v cc = 0 when v cc falls below 0.8v, the g684 reset output no longer sinks current?it becomes an open circuit. therefore, high-impedance cmos logic inputs con- nected to reset can drift to undetermined voltages. this presents no problem in most applications since most p and other circuitry is inoperative with vcc be- low 0.8v. however, in applications where reset ust be valid down to 0v, adding a pull-down resistor to reset causes any stray leakage currents to flow to ground, holding reset low (figure 2). r1?s value is not critical; 100k ? is large enough not to load reset and small enough to pull reset to ground. a 100k ? pull-up resistor to v cc is also recommended for the G685l if reset is required to remain valid for v cc < 0.8v. figure2. reset valid to v cc = ground circuit v cc reset gnd g684 r1 100k v cc reset gnd g684 r1 100k
ver: 1.2 jun 03, 2004 tel: 886-3-5788833 http://www.gmt.com.tw 6 g684/G685 global mixed-mode technology inc. interfacing to ps with bidirectional reset pins since the reset output on the g 685l is open drain, this device interfaces easily with ps that have bidirec- tional reset pins, such as the motorola 68hc11. connect- ing the p supervisor?s reset output directly to the microcontroller?s (c?s) reset pin with a single pull-up resistor allows either device to assert reset (figure 3). figure 3. interfacing to ps with bidirectional reset i/o G685l open-drain reset output allows use with multiple supplies generally, the pull-up connected to the G685l will connect to the supply voltage that is being monitored at the ic?s v cc pin. however, some systems may use the open-drain output to level-shift from the monitored sup- ply to reset circuitry powered by some other supply (figure 4). note that as the G685l?s v cc decreases below 1v, so does the ic?s ability to sink current at reset . also, with any pull-up, reset w ill be pulled high as vcc decays toward 0. the voltage where this occurs depends on the pull-up resistor value and the voltage to which it is connected. figure 4. G685l open-drain reset output allows use with multiple supplies benefits of highly accurate 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 sup- ply 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. the g68_ _463/g68_ _308 use highly accurate circuitry to ensure that reset is asserted close to the 5% limit, and long before the supply has declined to 10% below nominal. reset input gnd p v cc reset gnd G685 v cc v cc motorola 68hcxx r pull-up reset input gnd p v cc reset gnd G685 v cc v cc motorola 68hcxx r pull-up reset input gnd 5v system v cc reset gnd G685 v cc r pull-up +3.3v +5.0 reset input gnd 5v system v cc v cc r pull-up +3.3v +5.0v reset input gnd 5v system v cc reset gnd G685 v cc r pull-up +3.3v +5.0 reset input gnd 5v system v cc v cc r pull-up +3.3v +5.0v
ver: 1.2 jun 03, 2004 tel: 886-3-5788833 http://www.gmt.com.tw 7 g684/G685 global mixed-mode technology inc. package information note: 1. package body sizes exclude mold flash protrusions or gate burrs 2. tolerance 0.1000 mm (4mil) unless otherwise specified 3. coplanarity: 0.1000mm 4. dimension l is measured in gage plane dimensions in millimeters symbols min nom max a 1.00 1.10 1.30 a1 0.00 ----- 0.10 a2 0.70 0.80 0.90 b 0.35 0.40 0.50 c 0.10 0.15 0.25 d 2.70 2.90 3.10 e 1.40 1.60 1.80 e ----- 1.90(typ) ----- e1 ----- 0.95 ----- h 2.60 2.80 3.00 l 0.37 ------ ----- 1 1o 5o 9o taping specification gmt inc. does not assume any res ponsibility for use of any circuitry d escribed, no circuit patent licenses are implied and gmt inc. reserves the right at any time wit hout notice to change said circuitry and specifications. e e d h 1 l c b a2 a1 a e1 e e d h 1 l c b a2 a1 a e1 feed direction sot23-5 package orientation feed direction sot23-5 package orientation
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