ver: 2.7 oct 11, 2013 tel: 886-3-5788833 http://www.gmt.com.tw 1 g690/g691 global mixed-mode technology 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 (g690l) push-pull reset output (g690h) open-drain reset output (g691l) ? 140ms min power-on reset pulse width ? 10 a supply current ? guaranteed reset valid to v cc = +1v ? power supply transient immunity ? no external components ? 3-pin sot-23 and sc-70-3(sot-323) packages applications ? computers ? controllers ? intelligent instruments ? critical p and c power monitoring ? portable / battery-powered equipment ? automotive general description the g690/g691 are microprocessor ( p) supervisory circuits used 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- pow- ered circuits. these circuits perform a single function: they assert a reset signal whenever the v cc supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after v cc has risen above the reset threshold. reset thresholds suitable for operation with a variety of supply voltages are available. the g691l has an open-drain output stage, while the g690 have push-pull outputs. the g691l ? s open-drain reset output requires a pull-up resistor that can be connected to a voltage higher than v cc . the g690l have an active-low reset output, while the g690h 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 1v. low supply current makes the g690/g691 i deal for use in portable equipment. the g 690/g691 are available in 3-pin sot-23 and sc-70-3(sot-323) packages. pin configuration typical application circuit reset input gnd p v cc reset (reset) gnd g690/g691 v cc r pull-up v cc * *g691 only sot-23/sc-70-3(sot-323) 1 2 3 icc may increased at high t a , therefore, can not connect resistors to vcc to prevent icc abnormal behavior at high t a . reset input gnd p v cc reset (reset) gnd g690/g691 v cc r pull-up v cc * *g691 only sot-23/sc-70-3(sot-323) 1 2 3 reset input gnd p v cc reset (reset) gnd g690/g691 v cc r pull-up v cc * *g691 only sot-23/sc-70-3(sot-323) 1 2 3 icc may increased at high t a , therefore, can not connect resistors to vcc to prevent icc abnormal behavior at high t a .
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