AY vationat Semiconductor LM555/LM555C Timer General Description The LM555 is a highly stable device for generating accurate time delays or oscillation. Additional terminals are provided for triggering or resetting if desired. In the time delay mode of operation, the time is precisely controlled by one external re- sistor and capacitor. For astable operation as an oscillator, the free running frequency and duty cycle are accurately controlled with two external resistors and one capacitor. The circuit may be triggered and reset on falling waveforms, and the output circuit can source or sink up to 200 mA or drive TTL circuits. May 1997 Features Direct replacement for SE555/NE555 Timing from microseconds through hours Operates in both astable and monostable modes Adjustable duty cycle Qutput can source or sink 200 mA Qutput and supply TTL compatible Temperature stability better than 0.005% per C Normally on and normally off output Available in 8 pin MSOP package Applications Precision timing Pulse generation Sequential timing Time delay generation Pulse width modulation Pulse position modulation Linear ramp generator Schematic Diagram Veo THRESHOLD conTROL (2a VOLTAGE 1 GAD TRIGGER. a RESET 7 DISCHARGE a4 3 OuTPUT Dsoorest-1 1997 National Semiconductor Corporation Dso07651 www.national.com Jaw] OSSSINT/SSSIN1Absolute Maximum Ratings oie 2) It Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage +18V Power Dissipation (Note 3) LMI555H, LM555CH 760 mw LM555, LM555CN 1180 mw LM555CMM 613 mW Operating Temperature Ranges LM555 OS to +70C LMI555 55C to + 125C Electrical Characteristics notes 1, 2) (Ta = 25C, Veco = +5V to +15V, unless othewise specified) Storage Temperature Range -65C to +150C Soldering Information Dual-In-Line Package Soldering (10 Seconds) 260C Small Cutline Packages (SOIC and MSOP) Vapor Phase (60 Seconds) 215C Infrared (15 Seconds) 220C See AN-450 Surface Mounting Methods and Their Effect on Preduct Reliability for other methods of soldering surface mount devices. Limits Parameter Conditions LM555 LM555C Units Min Typ Max Min Typ Max Supply Voltage 45 18 45 16 Vv Supply Current Veco = 5V, RL = 5 3 6 mA Veco = 15V, RL = 10 12 10 15 mA (Low State) (Note 4) Timing Error, Monostable Initial Accuracy 05 1 % Drift with Temperature R, = 1k to 100 ka, 30 50 ppm/*C C = 0.1 uF, (Note 5) Accuracy over Temperature 15 1.5 % Drift with Supply 0.05 0.1 BV Timing Error, Astable Initial Accuracy 15 2.25 % Drift with Temperature Ra; Re = 1k to 100 kQ, 90 150 ppm/'G C = 0.1 uF, (Note 5) Accuracy over Temperature 25 3.0 % Drift with Supply 0.15 0.30 V/V Threshold Voltage 0.667 0.667 X Vee Trigger Voltage Voc = 15V 48 5 5.2 5 V Veo = 5V 1.45 1.67 1.9 1.67 Vv Trigger Current 0.01 0.5 0.5 0.9 pA Reset Voltage 0.4 0.5 1 04 0.5 1 Vv Reset Current 0.1 0.4 0.4 0.4 mA Threshold Current (Note 6) 0.1 0.25 0.1 0.25 pA Control Voltage Level Voc = 15V 9.6 10 10.4 9 10 ch V Voce = 5V 2.9 3.33 3.8 2.6 3.33 4 V Pin 7 Leakage Output High 1 100 1 100 nA Pin 7 Sat (Note 7) Qutput Low Veco = 15V, 1, = 15 mA 150 180 mv Qutput Low Veco = 45V, 1 =4.5 mA 70 100 80 200 mv www.national.comElectrical Characteristics (Notes 1, 2) (Continued) (Ta = 25C, Veg = +5V to +15V, unless othewise specified) Limits Parameter Conditions LM555 LM555C Units Min Typ Max Min Typ Max Output Voltage Drop (Low) Veco = 15V Isink = 10 mA 0.1 0.15 0.1 0.25 Vv Isinx = 50 mA 0.4 0.5 0.4 0.75 Vv loinc = 100 mA 2 2.2 2 25 v Isinmx = 200 mA 2.5 2.5 Vv Voc = 5V Isis = & MA 0.1 0.25 Vv lsine = 5 MA 0.25 0.35 Vv Qutput Voltage Drop (High) lsournce = 200 mA, Voc = 15V 125 12.5 V lsource = 100 MA, Vgg = 15V 13 133 12.75 13.3 Vv Voc = 5V 3 3.3 2.75 3.3 Vv Rise Time of Output 100 100 ns Fall Time of Output 100 100 ns Note 1: All voltages are measured with respect to the ground pin, unless otherwise specified Note 2: Absolute Maximum Ratings indicate limits beyond which damage te the device may occur. Operating Ratings indicate conditions for which the device is func- tional, but do net guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which quar- antee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is given, however, the typical value is a good indication of device performance Note 3: For operating at elevated temperatures the device must be derated above 25C based on a +150C maximum junction temperature and a thermal resistance of 164 CM (T0-5), 106C/W (DIP), 170C/W (S0-8), and 204CAW (MS OP} junction to ambient Note 4: Supply current when output high typically 1 mA less at Vee = SV. Note 5: Tested at Veo = SV and Ven = 15V, Note 6: This will determine the maximum value of Ra + Rg for 15V operation. The maximum total (Ra + Rp) is 20 MQ. Note 7: No protection against excessive pin 7 current is necessary providing the package dissipation rating will nct be exceeded. Note 8: Refer to RETSSSSX drawing of military LMSSSH and LM55SJ versions for specifications. Connection Diagrams Metal Can Package Dual-In-Line, Small Outline Veo and Molded Mini Small Outline Packages 1 a (7) DISCHARGE GND Vee {) THRESHOLD TRIGGER = ra] 1 suscHance CONTAOL VOLTAGE a OUTPUT THRESHOLD RESET DS0o7ss1-2 5 CONTROL Top View RESET VOLTAGE Order Number LM555H or LM555CH See NS Package Number HO8C DSOOTEST Top View Order Number LM555J, LM555CJ, LM555CM, LM555CMM or LM555CN See NS Package Number JO8A, MO&8A, MUAQSA or Nose 3 www.national.comTypical Performance Characteristics Minimuim Pulse Width Required for Triggering 12 V1 = 15 10 og 08 ar? af Os a4 O49 D2 al MINIMUM PULSE WEOTH (ust o o4 02 0.3 o4 LOWEST VOLTAGE LEVEL OF TRIGGEA PULSE (XK Vcc) S007 851-4 Low Output Voliage vs Output Sink Current 10 Woe - SY 55C ce) 10 (00 Tsung (may Dsco7851-21 Output Propagation Delay vs Voltage Level of Trigger Pulse 1200 4 1 T= +059 1000 | 4 2 vy > ' | f = a t ' : 2 Vee = 8.0 i = 80 } weld = 1 3 | | 2 sau. an s Veo 1V, 15 no 7 OV, = s00 4 pit | ' : | 0 04 2 0.3 LOWEST VOLTAGE LEVEL OF TANGER PULSE (X Vic) DS007es 1-24 Supply Current vs Supply Voltage 12 SUPPLY CURRENT (mA) m aT} 5s SUPPLY VOLTAGE (} DSooves1-19 Low Output Voliage vs Output Sink Current Veo - 10 95C Isinate IA) Dsge7Es 1-22 Output Propagation Delay vs Voltage Level of Trigger Pulse 1200 -15y 125C = 100 5 1G = 400 S 25C +24 . S 500 e <r z 100 : ~ t 200 C 0 0 o oz a3 LOWEST VOLTAGE LEWEL OF TRIGGER PULSE 4X Voct Dsco78s1-25 High Output Voltage vs Output Source Current z 1a 16 14 12 1 0.6 tb a4 az 0 Your (| ee 1 10 1h 'suurce [mAb DSooras1-20 Low Output Voliage vs Output Sink Current 10 Weg = 15V HEC Your (} 1 10 ton logy (mal DSoo7651-23 Discharge Transistor (Pin 7) Voltage vs Sink Current 1000 = Veg = 18 125C 100 = 425E = Mga, (mv) PIN? O01 a 1a 10 100 lgav (WAS PIN 7 DS00785 1-26 www.national.comTypical Performance Characteristics (continued) Discharge Transistor (Pin 7} Voltage vs Sink Current 1000 = Sv 100 Vay (mV) PIN 7 0.01 a. Applications Information MONOSTABLE OPERATION In this mode of operation, the timer functions as a one-shot (Figure 1). The external capacitor is initially held discharged by a transistor inside the timer. Upon application of a nega- tive trigger pulse of less than 1/3 Vee to pin 2, the flip-flop is set which both releases the short circuit across the capacitor and drives the output high. +SV TO +150 2 vy, RESET O+ ce L Ra I 4 TRIGGER DISCHARGE NORMALLY & 2 O-2 3 ron LoaD % Fe THRESH | LMS55 6 SHOLO | CONTROL OUTPUT VOLTAGE +; = NORMALLY A OFF Load b DS007851-5 FIGURE 1. Monostable The voltage across the capacitor then increases exponen- tially for a period of t= 1.1 R, , at the end of which time the voltage equals 2/3 Vor. The comparator then resets the flip-flop which in tum discharges the capacitor and drives the output to its low state. Figure 2 shows the waveforms gener- ated in this mode of operation. Since the charge and the threshold level of the comparator are both directly propor- tional to supply voltage, the timing internal is independent of supply. 10 100 Ising (mA) PINT Deoovest-27 0800785 1-5 Veo = 5V Top Trace: Input 5/Div TIME = 0.1 ms/DIV. Middle Trace: Cutput SV/Div. Ra = 9.1 k@ Bottom Trace: Gapacitor Voltage 2V/Div. C= 0.01 pF FIGURE 2. Monostable Waveforms During the timing cycle when the output is high, the further application of a trigger pulse will not effect the circuit so long as the trigger input is returned high atleast 10 ps before the end of the timing interval. However the circuit can be reset during this time by the application of a negative pulse to the reset terminal (pin 4). The output will then remain in the low state until a trigger pulse is again applied. When the reset function is notin use, it is recommended that it be connected to V.,. to avoid any possibility of false trig- gering. Figure 2 is a nomograph for easy determination of R, C val- ues for various time delays. NOTE: In monostable operation, the trigger should be driven high before the end of timing cycle. www.national.comApplications Information (continued) SVL _ a o 3 YY 3 1 & So a oO & 1 2 0.01 0.001 1045100 usimsidmsi00ms Is 10s 100s ty~ TIME DELAY DSoo785 1-7 FIGURE 3. Time Delay ASTABLE OPERATION If the circuit is connected as shown in Figure 4 (pins 2 and 6 connected) it will trigger itself and free run as a multivibrator. The external capacitor charges through Ry + Re and dis- charges through Ra. Thus the duty cycle may be precisely set by the ratio of these two resistors. rT gL, LM555 6 I | | +: gp LI o Dsoo7851-5 FIGURE 4. Astable In this mode of operation, the capacitor charges and dis- charges between 1/3 Veg and 2/3 Voc. As in the triggered mode, the charge and discharge times, and therefore the fre- quency are independent of the supply voltage. Figure 5 shows the waveforms generated in this mode of operation. OSo078s1-3 Ver = SV Top Trace: Output 5/Div TIME = 20 ps/DIV. Bottom Trace: Capacitor Voltage 1/Div Ra = 3.9 kO Ap = 3 kQ C = 0.01 uF FIGURE 5. Astable Waveforms The charge time {output high) is given by: t, = 0.693 (Ry + Rg) C And the discharge time (output low) by: tp = 0.693 (Ra) GC Thus the total period is: T=t, +t, = 0.693 (Ra +2Rg) C The frequency of oscillation is: f_ 1 1.44 T (Ra + 2Ag}C Figure 6 may be used for quick determination of these RC values. The duty cycle is: Re Db =3_ Ra + 28, 0.1 C GAPACITANCE (,.F) 0.01 (Ry + 2Re} 0.001 | OF 1) 10 100) tk 10k 100K [- FREE-RUNWING FREQUENCY (Hz) DSo07851-10 FIGURE 6. Free Running Frequency FREQUENCY DIVIDER The monostable circuit of Figure 1 can be used as a tre- quency divider by adjusting the length of the timing cycle. Figure 7 shows the waveforms generated in a divide by three circuit. www.national.comApplications Information (continued) wel ee lah eek DSo07851-11 Veo = 8 Top Trace: Input 4/Div TIME = 20 psDI. Midele Trace: Cutout 2V/ Div Ra = 9.1 kQ Bottom Trace: Capacitor 2V/Div C = 0.01 pF FIGURE 7. Frequency Divider PULSE WIDTH MODULATOR When the timer is connected in the monostable mode and triggered with a continuous pulse train, the output pulse width can be modulated by a signal applied to pin 5. Figure 8 shows the circuit, and in Figure 9 are some waveform examples. [tf R a 8 > DISCHARGE TRIGGER C+42 7 tages, LUNRESHOLD MODULATION INPUT QUTPUT O43 to -, ; OS00785 1-12 FIGURE 8. Pulse Width Modulator ATR *EEEUPRRR | Cheba b bed de OS007851-13 Vee = 5V Top Trace: Modulation 1/Div TIME = 6.2 ms/DIV. Bottom Trace: Output Voltage 2V/Div. Ra =91kQ C= 0.01 pF FIGURE 9. Pulse Width Modulator PULSE POSITION MODULATOR This application uses the timer connected for astable opera- tion, as in Figure 70, with a modulating signal again applied to the control voltage terminal. The pulse position varies with the modulating signal, since the threshold voltage and hence the time delay is varied. Figure 77 shows the waveforms generated for a triangle wave modulation signal. 0 vee , 3 " LMBG5 sg MOOULATION | QUTPUT Cnt 1_o t DSoorest-14 FIGURE 10. Pulse Position Modulator DSo0r8s1-15 Veo = 5V Top Trace: Modulation Input 1/Div. TIME = 0.1 ms/DIV. Bottom Trace: Output 2V/Div. Ra = 3.9 ko Rg = 3 ka C= 0.01 pF FIGURE 11. Pulse Position Modulator LINEAR RAMP When the pullup resistor, R,, in the monostable circuit is re- placed by a constant current source, a linear ramp is gener- ated. Figure 72 shows a circuit configuration that will perform this function. TRIEGERJ ? OUTPUT Que DScorasi-15 FIGURE 12. www.national.comApplications Information (continued) Figure 13 shows waveforms generated by the linear ramp. The time interval is given by: _ 2/3 Voc Re (Ry ~ Ra) C Ba Voc ~ Vee (Ri + Re) Vac = 0.6 Vee = 0.6V Ds0o7E51-17 Vor = SV Top Trace: Input 3/Div TIME = 20 us/DIV. Middle Trace: Output S/Div Ry = 47 kQ Bottom Trace: Capacitor Voltage 1 / Div. Re = 100 ko Re = 2.7kQ = 6.01 pF FIGURE 13. Linear Ramp 50% DUTY CYCLE OSCILLATOR For a 50% duty cycle, the resistors R, and Re may be con- nected as in Figure 74. The time period tor the output high is the same as previous, t; = 0.693 R, GC. For the output low it ist = Re a Gr Re)/(Ra | Pe) | C n [3 Ra Thus the frequency of oscillation is _ 1 {y + 1s Wer Ra R 51k B 4 8 ak 2 7 A, LM555 6 OUTPUT O1 3 c ODiaF OS007851-15 FIGURE 14. 50% Duty Cycle Oscillator Note that this circuit will not oscillate it Rp is greater than 1/2 R, because the junction of Ra and Rg cannot bring pin 2 down to 1/3 Vo, and trigger the lower comparator. ADDITIONAL INFORMATION Adequate power supply bypassing is necessary to protect associated circuitry. Minimum recommended is 0.1 HF in par- allel with 1 pF electrolytic. Lower comparator storage time can be as long as 10 us when pin 2 is driven fully to ground for triggering. This limits the monostable pulse width to 10 us minimum. Delay time reset to output is 0.47 ps typical. Minimum reset pulse width must be 0.3 us, typical. Pin 7 current switches within 30 ns of the output (pin 3) volt- age. www.national.comPhysical Dimensions inches (millimeters) lax 0.880-0.570 - (@.B909 398) a 0.315 0.335 | [* aon 6.50m O* MAX 0.025 0.165 0,185 4 Freese) UNCONTaOLLED 4.197 = 9.609) y \ Y- REFERENCE PLANE i bass LE SEATING PLANE 0.500 ~ 19.889) t 0.015 0.040 TEAC 10.381 1.016) Y a |, 0.060.019 wO6 OS ain TYP om ln (0.406 0.483) 0.195-0.205 DIA | pel Se ee 010 yp yp (4.953 5.207) PS. (2.540) ENN (737 1.143) So pozaooa |S, austous .711 0 864 aera ono ee (2.921 ~ 3.683) mA ~ 45 EDUALLY SPACED - MCHC (FEW Ei Metal Can Package (H} Order Number LM555H or LM555CH NS Package Number H0&8C 0.400 MAX RO.010 Ng a a rm | f 0.220 0.310 MAX SJ 0.291 GLASS RO.025 TYP | | 1} LF Let Le] 0.045 | o.ages TYP 0.290 IK 9.005 GLASS 4.320 MIN [sau 0.180 | ! hy AY MAX 0.200 LY Ss 0.020 WAX bose ! O28 an MIN . 0.200 goes 4 TYP O.055 MAX ey BOTH ENDS 0.008 a.arz [YP i 95 45 TYP i J J - 0.018 40.003 TYP Ceramic Dual-In-Line Package (J) Order Number LM555J or LM555CJ NS Package Number J08A 9.100 40,010 TYP JDSA [REV KE} www.national.comO10 - 0.157 | 13.810 3.988) UUW 0.020 4 45. ae (0.254 -0.508) | j A po cae Fa & MAX OIYP ALL LEADS: ' (0.102) aoe peo TA Onan BEAL ALL LEAD TIPS s (0.203 0.254) >| | O.n16-a.us0 TYP ALL LEADS 7.806 1370, TYP ALL LEADS Physical Dimensions inches (millimeters) (Continued) 0.189 - 0.197 eel I t4.200 5.004) | Afat O 22 24d (9.797 6.798) 0.053 0.059 [Vale 1.753) zi) 0.014 _ | (0.355) aan | |-a- 010 aK MY in.t58i at 4 Tip O.Ub4 0.010 40.102 - 6.254) SEATING + PLANE 0.0140.020 yp (0 356 0,506) P A008 17) elle (0.203) Small Outline Package (M) Order Number LM555CM NS Package Number M038A MA Py -h www.national.comPhysical Dimensions inches (millimeters) (Continued) 9.11840.004 [f}-4- [340.1] +] 1000 Hee 0.11820.004 (0.189) 9.19340.004 (ei re [4.940.1] . * (0. a0 . [az] 7P ao PINT =" PH IDENT Hs ie 018) poe - [oar] 7 P 0 0286) TP | 4 <+| fenes5 m25E) T4P LAND PATTERN RECCMMZNDATION reer 65] 0.005 R TYP [9.13] GAGE 0.037-0.043_ o008 BAF [0.94-1.08] 2a TP .027 [0.5 7h ne] Le [9.002 [2.05] Ole [cQ] 3-Lead (0.118 Wide) Molded Mini Small Outline Package CHEB Tacha | |. | 9.00740.002 [9. 1840.05] Order Number LM555CMM NS Package Number MUAQ8A 0,02140.005 } [0.5340.12] oe - 6 TYP SEATING PLANC TYP MLagas [REY 6: www.national.comLM555/LM555C Timer Physical Dimensions inches (millimeters) (Continued) 0.373 - 0,400 79.474 10.16) 7) 9.090 . (2.288) U052 4 fe) [71 [1 [1 0,032 0.005 (2.337) ~, i (.8130.127) * \ oo 0.250 + 0.006 RAD PIN NOL TIENT re (6.95 40.127) PIN NO. 1 IDENT artion1 CG L2] Lat fy 0.280 0.040 a b 0,040, i7t1a) MIN 0.030 Te re| be DPTION 2 max (1.016) 0.039 0.300 0.320 (0.762) | be 0.145 0,200 Tl aza.ac8) | { 20 = hy jf (0.981) (3.683 5.080) 28. i { ot 7 A onan 0.005 a _. JI] (390240127) op aA +, at 0.125 0.140 ~ 0.065 (2.175 3.588) D125 1.651) - ; 0.020, 0,009 0.015 fag go" + 4 (0.508) (0.229 0.381} . IA TYP MIN +0.040 Nob | 1.018 +0.003 0.325 7 Faas (457 0.076) +1.016 _ 0.100=0,010 {3.255 1 oan) (2.540 0.254) mace | _ el a .050 (1.524) 41.270) ROSE (REW Fa Molded Dual-In-Line Package (N) Order Number LM555CN NS Package Number NO8E LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DE- VICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMI- CONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or sys- tems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose fail- ure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. Acritical component in any component ot a life support device or system whose failure to perform can be rea- sonably expected to cause the failure of the life support device or system, or to affact its safety or etfectivenass. National Semiconductor Corporation 1141 West Bardin Road Arlington, TX 76017 Tel: 1{800) 272-9959 Fax: 1(800) 737-7018 www.national.com National Semiconductor Europe Fax: (449) 0-480-530 85 66 Email: cnjwge@tevm2.nsc.com Beutsch Tel: (+49) 0-160-580 65 65 English Tel: (449) 0-160-532 76 32 Frangais Tel: (449) 0-160-532 95 58 ttaliano Tel: (+49) 0-180-534 16 80 National Semiconductor Hong Kong Ltd. 18th Floor, Straight Block, Ocean Centre, 5 Canton Rd. Tsimshatsui, Kowloon Hong Kong Tel: (852) 2737-1600 Fax: (852) 2736-9960 National Semiconductor Japan Ltd. Tel: 61-043-299-2508 Fax: @1-048-299-2408 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.