MC3456 DUAL TIMING CIRCUIT

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1 Order this document by /D The dual timing circuit is a highly stable controller capable of producing 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 resistor and capacitor per timer. For astable operation as an oscillator, the free running frequency and the duty cycle are both accurately controlled with two external resistors and one capacitor per timer. The circuit may be triggered and reset on falling waveforms, and the output structure can source or sink up to 2 ma or drive MTTL circuits. Direct Replacement for NE6/SE6 Timers Timing from Microseconds through Hours Operates in Both Astable and Monostable Modes Adjustable Duty Cycle High Current can Source or Sink 2 ma can Drive MTTL Temperature Stability of.% per C Normally On or Normally Off Dual Version of the Popular MC4 Timer DUAL TIMING CIRCUIT P SUFFIX PLASTIC PACKAGE CASE 646 SEMICONDUCTOR TECHNICAL DATA PIN CONNECTIONS D SUFFIX PLASTIC PACKAGE CASE (SO4) Figure. 22 Second Solid State Time Delay Relay Circuit k µf Figure 3. General Test Circuit Test circuit for measuring DC parameters (to set output and measure parameters): a) When V S 2/3, V O is low. b) When V S /3, V O is high. c) When V O is low, Pin sinks current. To test for, set V O high, c) apply voltage, and test for current flowing into Pin. When c) is not in use, it should be tied to. k MOTOROLA ANALOG IC DEVICE DATA 4 2 t =.; R and C = 22 sec Time delay (t) is variable by changing R and C (see Figure 6). + V O µf C MT2 2 M G MT N44 V R I CC 4 8 Voltage 3 I Sink I Source R Load V N43 6 I th 2. k V S 2 3. k 2 V µf + Vac/6 Hz 2 (2) 3 () Voltage 6 (8) A A A VCC 3 B 2 B A 4 B A B A B B Device P NE6D (Top View) ORDERING INFORMATION Operating Temperature Range to + C Package Plastic DIP SO4 Figure 2. Block Diagram ( Shown) k k k 4 + Comp A + Comp B R S Flip Flop Q Inhibit/ 4 () (3) (9) Motorola, Inc. 996 Rev 2

2 MAXIMUM RATINGS (TA = +, unless otherwise noted.) Rating Symbol Value Unit Power Supply Voltage +8 Vdc Current I dis 2 ma Power Dissipation (Package Limitation) P Suffix, Plastic Package, Case 646 Derate above T A = + D Suffix, Plastic Package, Case Derate above T A = + P D mw mw/ C W mw/ C Operating Ambient Temperature Range T A to + C Storage Temperature Range T stg 6 to + C ELECTRICAL CHARACTERISTICS (TA = +, VCC = + V, unless otherwise noted.) Characteristics Symbol Min Typ Max Unit Supply Voltage 4. 6 V Supply Current =. V, R L = = V, R L = Low State, (Note ) I CC ma Timing Error (Note 2) Monostable Mode (R A = 2. kω; C = µf) Initial Accuracy Drift with Temperature Drift with Supply Voltage Astable Mode (R A = R B = 2. kω to kω; C = ) Initial Accuracy Drift with Temperature Drift with Supply Voltage % PPM/ C %/V % PPM/ C %/V Voltage V th 2/3 x Voltage V T V = V =. V..6 Current I T. µa Voltage V R.4. V Current I R ma Current (Note 3) I th.3 µa Voltage Level V CL V = V =. V Voltage Low ( = V) I Sink = ma I Sink = ma I Sink = ma I Sink = 2 ma ( =. V) I Sink =. ma Voltage High (I Source = 2 ma) = V (I Source = ma) = V =. V Toggle Rate R A = 3.3 kω, R B = 6.8 kω, C =.3 µf (Figure, 9) khz Leakage Current I dis 2 na Rise Time of t OLH ns Fall Time of t OHL ns Matching Characteristics Between Sections Monostable Mode Initial Timing Accuracy Timing Drift with Temperature Drift with Supply Voltage V OL V OH NOTES:. Supply current is typically ma less for each output which is high. 2. Tested at =. V and = V. 3. This will determine the maximum value of R A + R B for V operation. The maximum total R = 2 mω ± V V % ppm/ C %/V 2 MOTOROLA ANALOG IC DEVICE DATA

3 Figure 4. Pulse Width Figure. Supply Current PW, PULSE WIDTH (ns MIN) 2 2 C C I CC, SUPPLY CURRENT (ma) VT (min), MINIMUM TRIGGER VOLTAGE (X VCC = Vdc).4. VCC, SUPPLY VOLTAGE (Vdc) 2. Figure 6. High Voltage Figure. Low Voltage (@ VCC =. Vdc).8 V OH (Vdc) V VCC V V OL, (Vdc) ISource (ma) ISink (ma) Figure 8. Low Voltage (@ VCC = Vdc) Figure 9. Low Voltage (@ VCC = Vdc) V OL, (Vdc) V OL, (Vdc) ISink (ma) ISink (ma) MOTOROLA ANALOG IC DEVICE DATA 3

4 Figure. Delay Time versus Supply Voltage Figure. Delay Time versus Temperature td, DELAY TIME NORMALIZED td, DELAY TIME NORMALIZED VCC, SUPPLY VOLTAGE (Vdc) TA, AMBIENT TEMPERATURE ( C) Figure 2. Propagation Delay versus Voltage 3 tpd, PROPAGATION DELAY TIME (ns) 2 2 C C VT (min), MINIMUM TRIGGER VOLTAGE (x VCC = Vdc) 4 MOTOROLA ANALOG IC DEVICE DATA

5 Figure 3. Representative Circuit Schematic Voltage VCC Comparator Comparator FlipFlop 4. k k k 6.8 k. k. k 3.9 k k c b. k e 4. k c b 22 k. k 4. k GENERAL OPERATION The is a dual timing circuit which uses as its timing elements an external resistor/capacitor network. It can be used in both the monostable (one shot) and astable modes with frequency and duty cycle, controlled by the capacitor and resistor values. While the timing is dependent upon the external passive components, the monolithic circuit provides the starting circuit, voltage comparison and other functions needed for a complete timing circuit. Internal to the integrated circuit are two comparators, one for the input signal and the other for capacitor voltage; also a flipflop and digital output are included. The comparator reference voltages are always a fixed ratio of the supply voltage thus providing output timing independent of supply voltage. Monostable Mode In the monostable mode, a capacitor and a single resistor are used for the timing network. Both the threshold terminal and the discharge transistor terminal are connected together in this mode (refer to circuit Figure ). When the input voltage to the trigger comparator falls below /3 VCC the comparator output triggers the flipflop so that it s output sets low. This turns the capacitor discharge transistor off and drives the digital output to the high state. This condition allows the capacitor to charge at an exponential rate which is set by the RC time constant. When the capacitor voltage reaches 2/3 VCC the threshold comparator resets the flipflop. This action discharges the timing capacitor and returns the digital output to the low state. Once the flipflop has been triggered by an input signal, it cannot be retriggered until the present timing period has been completed. The time that the output is high is given by the equation t =. RA C. Various combinations of R and C and their associated times are shown in Figure 4. The trigger pulse width must be less than the timing period. A reset pin is provided to discharge the capacitor thus interrupting the timing cycle. As long as the reset pin is low, the capacitor discharge transistor is turned on and prevents the capacitor from charging. While the reset voltage is applied the digital output will remain the same. The reset pin should be tied to the supply voltage when not in use. C, CAPACITANCE ( µ F). Figure 4. Time Delay. µs µs ms ms ms td, TIME DELAY (s) MOTOROLA ANALOG IC DEVICE DATA

6 Figure. Monostable Circuit + (. V to V) Figure 6. Monostable Waveforms R L R L (9) 6 (8) 4 () Pin numbers in parenthesis ( ) indicate BChannel 4 (3) 2 (2) 3 () Voltage R A C t = µs/cm (R A = kω, C =, R L = kω, = V) Figure. Astable Circuit + (. to V) Figure 8. Astable Waveforms R L 4 () 4 R A (3) R L (9) 6 (8) 2 (2) 3 () Voltage R B C t = 2 µs/cm (R A =. kω, C =. µf, R L = kω, R B = 3.9 kω, = V) Astable Mode In the astable mode the timer is connected so that it will retrigger itself and cause the capacitor voltage to oscillate between /3 VCC and 2/3 VCC (see Figure ). The external capacitor charges to 2/3 VCC through RA and RB and discharges to /3 VCC through RB. By varying the ratio of these resistors the duty cycle can be varied. The charge and discharge times are independent of the supply voltage. The charge time (output high) is given by: t =.69 (RA+RB) C The discharge time (output low) by: t2 =.69 (RB) C Thus the total period is given by: T = t + t2 =.69 (RA + 2RB) C The frequency of oscillation is then: f = T =.44 (RA +2RB) C and may be easily found as shown in Figure 9. The duty cycle is given by: DC = RB RA +2RB To obtain the maximum duty cycle, RA must be as small as possible; but it must also be large enough to limit the discharge current (Pin current) within the maximum rating of the discharge transistor (2 ma). The minimum value of RA is given by: C, CAPACITANCE ( µ F). RA (Vdc) I (A) (Vdc).2 Figure 9. Free Running Frequency (RA + 2 RB). k k k f, FREE RUNNING FREQUENCY (Hz) 6 MOTOROLA ANALOG IC DEVICE DATA

7 Tone Burst Generator For a tone burst generator, the first timer is used as a monostable and determines the tone duration when triggered by a positive pulse at Pin 6. The second timer is enabled by the high output of the monostable. It is connected as an astable and determines the frequency of the tone. APPLICATIONS INFORMATION Dual Astable Multivibrator This dual astable multivibrator provides versatility not available with single timer circuits. The duty cycle can be adjusted from % to 9%. The two outputs provide two phase clock signals often required in digital systems. It can also be inhibited by use of either reset terminal. Figure 2. Tone Burst Generator R T 4 4 R A + V R B C. mf C2 t =. R T C f =.44 (R A + 2R B ) C Figure 2. Dual Astable Multivibrator + V R 4 4 k N94 N94 k R C Voltage 3 Voltage C2 f =.9 R2 (R + R2) C for C = C2 Duty Cycle R + R2 MOTOROLA ANALOG IC DEVICE DATA

8 Pulse Width Modulation If the timer is triggered with a continuous pulse train in the monostable mode of operation, the charge time of the capacitor can be varied by changing the control voltage at Pin 3. In this manner, the output pulse width can be modulated by applying a modulating signal that controls the threshold voltage. Test Sequences Several timers can be connected to drive each other for sequential timing. An example is shown in Figure 24 where the sequence is started by triggering the first timer which runs for ms. The output then switches low momentarily and starts the second timer which runs for ms and so forth. Figure 22. Pulse Width Modulation Waveforms Figure 23. Pulse Width Modulation Circuit + (. V to V) Modulation Input Voltage. V/cm Clock Input Voltage. V/cm Voltage. V/cm Capacitor Voltage. V/cm R L 4 () 4 (9) Clock 6 (8) Input (3) 2 (2) 3 () R A Modulation Input C t =. ms/cm (RA = kw, C =.2 mf, VCC = V) Figure 24. Sequential Timing Circuit (. V to V) 9. k 2 k 9. k 2 k k. µf. µf µf. µf. µf Load Load Load 8 MOTOROLA ANALOG IC DEVICE DATA

9 4 8 A F H G D N B SEATING PLANE C K OUTLINE DIMENSIONS P SUFFIX PLASTIC PACKAGE CASE 6466 ISSUE L L M J NOTES:. LEADS WITHIN 3 (.) RADIUS OF TRUE POSITION AT SEATING PLANE AT MAXIMUM MATERIAL CONDITION. 2. DIMENSION L TO CENTER OF LEADS WHEN FORMED PARALLEL. 3. DIMENSION B DOES NOT INCLUDE MOLD FLASH. 4. ROUNDED CORNERS OPTIONAL. INCHES MILLIMETERS DIM MIN MAX MIN MAX A B C D F G. BSC 2.4 BSC H J K L.3 BSC.62 BSC M N A 4 B 4X P.2 (.) M B M D SUFFIX PLASTIC PACKAGE CASE (SO4) ISSUE N NOTES:. DIMENSIONING AND TOLERANCING PER ANSI Y4.M, CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION (.6) PER SIDE.. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 2 (.) TOTAL IN EXCESS OF THE D DIMENSION AT MAXIMUM MATERIAL CONDITION. T G 8X D K C SEATING PLANE.2 (.) M T B S A S M R X 4 J F MILLIMETERS INCHES DIM MIN MAX MIN MAX A B C D F G.2 BSC. BSC J K M P R MOTOROLA ANALOG IC DEVICE DATA 9

10 Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Typical parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including Typicals must be validated for each customer application by customer s technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; JAPAN: Nippon Motorola Ltd.; TatsumiSPDJLDC, 6F SeibuButsuryuCenter, P.O. Box 292; Phoenix, Arizona or Tatsumi KotoKu, Tokyo 3, Japan MFAX: RMFAX@ .sps.mot.com TOUCHTONE ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, INTERNET: Ting Kok Road, Tai Po, N.T., Hong Kong MOTOROLA ANALOG IC DEVICE /D DATA

DUAL TIMING CIRCUIT SEMICONDUCTOR TECHNICAL DATA PIN CONNECTIONS ORDERING INFORMATION. Figure Second Solid State Time Delay Relay Circuit

DUAL TIMING CIRCUIT SEMICONDUCTOR TECHNICAL DATA PIN CONNECTIONS ORDERING INFORMATION. Figure Second Solid State Time Delay Relay Circuit The MC3456 dual timing circuit is a highly stable controller capable of producing accurate time delays, or oscillation. Additional terminals are provided for triggering or resetting if desired. In the