LND555 precision timing circuit gnd vcc trigger discharge out threshold reset control voltage data sheet general description ? timing from microseconds to hours ? astable or monostable operation ? adjustable duty cycle ? ttl-compatible output can sink or source up to 200ma ? temperature stability of 0.005% per c ? direct replacement for signetics ne555 timers features the LND555 is a monolithic timing circuit capable of producing accurate time delays or oscillation. in the time delay mode of operation, the timed interval is controlled by a single external resistor and capacitor network. in the astable mode of operation, the frequency and duty cycle may be independently controlled with two external resistors and a single external capacitor. applications ? precision timing ? pulse generation ? sequential timing ? time delay generation ? pulse width modulation ? pulse position modulation ? missing pulse detector pin configuration 1 8 2 7 3 6 4 5 ? linear dimensions, inc. ? 445 east ohio street, chicago il 60611 usa ? tel 312.321.1810 ? fax 312.321.1830 ? www.lineardimensions.com ?
(t a = 25c, unless otherwise specified) parameter min max units supply voltage, v cc 4.5 16 input voltage(control, reset, threshold and trigger) v cc v output current 200 ma operating free-air temperature 70 c storage temperature range, tstg -65 +150 reset trigger voltage threshold voltage* output discharge switch low irrelevant irrelevant low on high <1/3v cc high high off high >1/3 v cc >2/3 v cc low on high >1/3 v cc <2/3vcc as previously established *voltage levels shown are normal absolute maximum rating LND555 function table block diagram reset can override trigger, which can override threshold ? linear dimensions, inc. ? 445 east ohio street, chicago il 60611 usa ? tel 312.321.1810 ? fax 312.321.1830 ? www.lineardimensions.com ?
(t a =25c, vcc=+5 to +15v, unless otherwise specified ) parameter test conditions (see note 2) min typ max units operating supply voltage range 4.5 16 v threshold voltage level v cc =15v v cc =5v 8.8 2.4 10 3.3 11.2 4.2 v v threshold current(see note 1) (see note 1) 30 250 na trigger voltage level v cc =15v v cc =5v 4.5 1.1 5 1.67 5.6 2.2 v trigger current trigger at 0 v 0.5 2 a reset voltage level 0.3 0.7 1 v reset current reset at v cc reset at 0v 0.1 -0.4 0.4 -1.5 ma discharge leakage current 20 100 na control voltage level vcc=15v v cc =5v 9 2.6 10 3.3 11 4 v v low-level output voltage v cc =15v v cc =5v i ol =10ma i ol =50ma i ol =100ma i ol =200ma i ol =5ma i ol =8ma 0.1 0.4 2 2.5 0.25 0.3 0.25 0.75 2.5 0.35 0.4 v high- level output voltage v cc =15v i ol = -100ma i ol = -200ma i ol = -100ma 12.75 2.75 13.3 12.5 3.3 v supply current output low, no load output high, no load v cc =15 v v cc =5 v v cc =15 v v cc =5 v 10 3 9 2 15 6 13 5 ma initial error of timing interval (see note 3) monostable (note 4) astable (note 5) t a =25 c 1 5 3 13 % temperature coefficient of timing interval monostable astable t a = min to max 50 150 150 500 ppm/ c supply voltage sensitivity of timing interval monostable astable t a =25 c 0.1 0.3 0.5 1 %/v output pulse rise time c l = 15pf, t a =25 c 100 300 ns output pulse fall time c l = 15pf, t a =25 c 100 300 ns electrical characteristics LND555 ? linear dimensions, inc. ? 445 east ohio street, chicago il 60611 usa ? tel 312.321.1810 ? fax 312.321.1830 ? www.lineardimensions.com ?
notes: 1. this parameter influences the maximum value of the timing resistors r a and r b in the circuit on figure 1. for example, when vcc=5v, the maximum value is r=r a +r b =3.4 m ? , and vcc=15v, the maximum value is 10m ? . 2. for conditions shown as min or max, use the appropriate value specified under recommended operating conditions. 3. timing interval error is defined as the difference between the measured value and the average value of a random sample from each process run. 4. values specified are for a device in a monostable circuit similar to figure.2, with component values as follow: r a =2k ? to 100 k ? , c=0.1 f. 5. values specified are for a device in an astable circuit similar to figure.1, with component values as follow: r a , r b =1k ? to 100k ? , c=0.1 f. LND555 typical application data LND555 figure 1 :circuit for astable operation note a : bypassing the control voltage input to the ground with a capacitor may improve operation. this should be evaluated for individual applications LND555 figure 2 : circuit for monostable operation ? linear dimensions, inc. ? 445 east ohio street, chicago il 60611 usa ? tel 312.321.1810 ? fax 312.321.1830 ? www.lineardimensions.com ?
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