supply voltage monitor issue 1 - march 1998 zsh560 device description the zsh560 is a three terminal under voltage monitor circuit for use in microprocessor systems. the threshold voltage of the device has been set to 4.6 volts making it ideal for 5 volt circuits. included in the device is a precise voltage reference and a comparator with built in hysteresis to prevent erratic operation. the zsh560 features an open collector output capable of sourcing at least l0ma which only requires a single external resistor to interface to following circuits. operation of the device is guaranteed from one volt upwards, from this level to the device threshold voltage the output is held high providing a power on reset function. should the supply voltage, once established, at any time drop below the threshold level then the output again will pull high. the device is available in a to92 package for through hole applications as well as so8 and sot223 for surface mount requirements. features so8, sot223 and to92 packages power on reset generator automatic reset generation low standby current guaranteed operation from 1 volt wide supply voltage range internal clamp diode to discharge delay capacitor 4.6 volt threshold for 5 volt logic 20mv hysteresis prevents erratic operation applications microprocessor systems computers computer peripherals instrumentation automotive battery powered equipment vcc out gnd schematic diagram 4-334
test conditions (t amb =25c for typical values, t amb =-40 to 85c for min/max values (note3)) comparator parameter symbol min typ. max. units threshold voltage low state output (vcc increasing) v il 4.5 4.61 4.7 v threshold voltage high state output (vcc decreasing) v ih 4.5 4.59 4.7 v hysteresis v h 0.01 0.02 0.05 v ouput parameter symbol min typ. max. units output source saturation: v oh (v cc =4.0v, i source =8.0ma) v cc -1.3 v (v cc =4.0v, i source =2.0ma) v cc -1.2 v (v cc =1.0v, i source =2 m a) v cc -0.4 v onstate output source current (v cc =4.0v, output=0v) i source 10 20 50 ma offstate output leakage current (v cc =5.0v, output=0v) i oh 0.02 0.5 m a clamp diode forward voltage (i f =10ma) v f 0.6 1.2 1.5 v propagation delay (v in 5v to 4v, r l =10k, t amb =25c) t d 1.5 m s total device parameter symbol min typ. max. units operating input voltage range v cc 1.0 to 6.5 v quiescent input current (v cc =5v) i q 135 200 m a note: 1. maximum package power dissipation must be observed. 2. maximum power dissipation, for the sot223 and so8 packages, is calculated assuming that the device is mounted on a pcb measuring 2 inches square. 3. low duty cycle pulse techniques are used during test to maintain junction temperatures as close to ambient as possible. zsh560 absolute maximum rating input supply voltage -1 to 10v offstate output voltage 10v onstate output source current( note 1 ) internally limited clamp diode forward current( note 1 ) 100ma operating junction temperature 150c operating temperature -40 to 85c storage temperature -55 to 150c power dissipation to92 780mw sot223 2w( note 2 ) so8 780mw( note 2 ) 4-335
-40 -20 0 20 40 60 80 100 4.50 4.55 4.60 4.65 4.70 temperature (c) threshold voltage v temperature threshold voltage (v) upper threshold lower threshold forward voltage (v) forward current (ma) clamp diode forward current v 85c 25c -40c vin = 0v 0 0.4 0.8 1.2 1.6 0 20 40 60 80 100 0123 time ( m s) reset delay time 0 2 4 5 v out (v) v in (v) rl = 10k w 0 0.4 0.8 1.2 1.6 2.0 0 0.1 0.2 0.3 0.4 output saturation voltage (v) source current (ma) output saturation voltage v source current 0 10 20 30 85c 25c -40c 85c 25c -40c 0246810 0 100 200 300 400 500 input voltage (v) input current v input voltage input current ( m a) -40c 25c 85c 012345 0 1 2 3 4 5 input voltage (v) output voltage (v) output voltage v input voltage rl = 10k w ta = 25c voltage ' ' ' ' typical characteristics zsh560 4-336
timing diagram application circuit zsh560 4-337 note 4: a time delayed reset can be accomplished with the additional cd. t dy = rcd ? ln ? ? ? ? 1 v th v in ? ? - ln ? ? ? ? 1 1 - v sat v in ? ? ? t dy =time (seconds) v th =microprocessor reset threshold (ground referenced) v sat =output saturation voltage ( from output saturation voltage characteristic) v in =power supply voltage
so8 package suffix C n8 top view to92 package suffix C c bottom view sot223 package suffix C g top view C connect pin 4 to pin 2 or leave pin 4 electrically isolated connection diagrams part no package partmark zsh560c to92 zsh560 zsh560g sot223 zsh560 ZSH560N8 so8 zsh560 ordering information zsh560 4-338
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