1 of 5 041002 features automatically restarts microprocessor after power failure maintains active-high reset for 350 ms after v cc returns to an in-tolerance condition accurate 5%, 10% or 15% microprocessor 5v power supply monitoring reduces need for discrete components precision temperature-compensated voltage reference and voltage sensor low-cost to-92 package or surface mount sot-223 package internal 5k pull-up resistor operating temperature of -40 c to +85 c pin assignment pin description pin 1 ground pin 2 reset pin 3 v cc pin 4 ground (sot-223 only) description the ds1833 econoreset uses a precis ion temperature compensated refe rence and comparator circuit to monitor the status of the power supply (v cc ). when an out-of-tolerance condition is detected, an internal power fail signal is generated which forces reset to the active (high) state. when v cc returns to an in- tolerance condition, the reset signal is kept in the active state for approximately 350 ms to allow the power supply and processor to stabilize. operation - power monitor the ds1833 provides the functions of detecting out-o f-tolerance power supply conditions and warning a processor-based system of impe nding power failure. when v cc is detected as out-of-tolerance, as defined by the tolerance of the part selected, the rs t signal is asserted. on power-up, rst is kept active for approximately 350 ms after the power supply has re ached the selected tolerance. this allows the power supply and microprocessor to stabilize before rst is released. ds1833 5v econoreset www.maxim-ic.com 1 2 3 1 2 3 bottom view to-92 package see mech. drawings section on website 2 3 4 top view sot-23 package see mech. drawings section on website 1 dallas ds1833 econo reset
ds1833 2 of 5 block diagram figure 1 application example figure 2
ds1833 3 of 5 power-up figure 3 power-down figure 4
ds1833 4 of 5 absolute maximum ratings* voltage on v cc pin relative to ground -0.5v to +7.0v voltage on i/o relative to ground -0.5v to v cc +0.5v operating temperature -40 c to +85 c storage temperature -55 c to +125 c soldering temperature 260 c for 10 seconds * this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability. recommended dc operating conditions (-40 c to +85 c) parameter symbol min typ max units notes supply voltage v cc 1.2 5.0 5.5 v 1 dc electrical characteristics (-40 c to +85 c; v dd =5v 10%) parameter symbol min typ max units notes low level @ rst v ol 0.4 v 1 output current @ 0.4v i ol +8 ma operating current i cc 1.5 2 ma v cc trip point 5% v cctp1 4.5 4.625 4.74 v 1 v cc trip point 10% v cctp2 4.25 4.375 4.49 v 1 v cc trip point 15% v cctp3 4.0 4.125 4.24 v 1 output capacitance c out 10 pf internal pull-up resistor r p 3.75 5 6.25 k ac electrical characteristics (-40 c to +85 c; v cc =5v 10%) parameter symbol min typ max units notes reset active time t rst 250 350 450 ms v cc detect to rst t rpd 100 ns v cc slew rate (4.75v - 4.00v) t f 300 s v cc slew rate (4.00v - 4.75v) t r 0ns v cc detect to rst t rpu 250 350 450 ms notes: 1. all voltages are referenced to ground.
ds1833 5 of 5 econoreset selec tion guide vcc trip point pushbutton detect min typ max min typ max ds1233-15 4.0 4.125 4.24 2.4 - 3.3 ds1233-10 4.25 4.375 4.49 2.4 - 3.3 ds1233-5 4.5 4.625 4.75 2.4 - 3.3 ds1233d-15 4.0 4.125 4.24 n/a n/a ds1233d-10 4.25 4.375 4.49 n/a n/a ds1233d-5 4.5 4.625 4.75 n/a n/a ds1833-15 4.0 4.125 4.24 n/a n/a DS1833-10 4.25 4.375 4.49 n/a n/a 5v ds1833-5 4.5 4.625 4.75 n/a n/a ds1233a-15 2.64 2.72 2.80 1.8 - 3.0 3.3v ds1233a-10 2.8 2.88 2.97 1.8 - 3.0
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