MC14490 Hex Contact Bounce Eliminator The MC14490 is constructed with complementary MOS enhancement mode devices, and is used for the elimination of extraneous level changes that result when interfacing with mechanical contacts. The digital contact bounce eliminator circuit takes an input signal from a bouncing contact and generates a clean digital signal four clock periods after the input has stabilized. The bounce eliminator circuit will remove bounce on both the “make” and the “break” of a contact closure. The clock for operation of the MC14490 is derived from an internal R−C oscillator which requires only an external capacitor to adjust for the desired operating frequency (bounce delay). The clock may also be driven from an external clock source or the oscillator of another MC14490 (see Figure 5). NOTE: Immediately after powerup, the outputs of the MC14490 are in indeterminate states. Features • • • • • • • • • • • • • http://onsemi.com MARKING DIAGRAMS PDIP−16 P SUFFIX CASE 648 16 MC14490P AWLYYWWG 1 1 Diode Protection on All Inputs Six Debouncers Per Package Internal Pullups on All Data Inputs Can Be Used as a Digital Integrator, System Synchronizer, or Delay Line Internal Oscillator (R−C), or External Clock Source TTL Compatible Data Inputs/Outputs Single Line Input, Debounces Both “Make” and “Break” Contacts Does Not Require “Form C” (Single Pole Double Throw) Input Signal Cascadable for Longer Time Delays Schmitt Trigger on Clock Input (Pin 7) Supply Voltage Range = 3.0 V to 18 V Chip Complexity: 546 FETs or 136.5 Equivalent Gates Pb−Free Packages are Available* MAXIMUM RATINGS (Voltages Referenced to VSS) Parameter DC Supply Voltage Range Symbol Value Unit VDD −0.5 to +18.0 V Vin, Vout −0.5 to VDD + 0.5 V Input Current (DC or Transient) per Pin Iin ± 10 mA Power Dissipation, per Package (Note 1) PD 500 mW Ambient Temperature Range TA −55 to +125 °C Storage Temperature Range Tstg −65 to +150 °C Lead Temperature (8−Second Soldering) TL 260 °C Input or Output Voltage Range (DC or Transient) June, 2006 − Rev. 7 1 SOIC−16 DW SUFFIX CASE 751G 14490 AWLYYWWG 1 1 16 SOEIAJ−16 F SUFFIX CASE 966 MC14490 ALYWG 1 1 A WL, L YY, Y WW, W G = Assembly Location = Wafer Lot = Year = Work Week = Pb−Free Package ORDERING INFORMATION Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. 1. Temperature Derating: Plastic “P and D/DW” Packages: – 7.0 mW/_C From 65_C To 125_C This device contains protection circuitry to guard against damage due to high static voltages or electric fields. However, precautions must be taken to avoid applications of any voltage higher than maximum rated voltages to this high−impedance circuit. For proper operation, Vin and Vout should be constrained to the range VSS v (Vin or Vout) v VDD. Unused inputs must always be tied to an appropriate logic voltage level (e.g., either VSS or VDD). Unused outputs must be left open. © Semiconductor Components Industries, LLC, 2006 16 See detailed ordering and shipping information in the package dimensions section on page 9 of this data sheet. *For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. Publication Order Number: MC14490/D MC14490 PIN ASSIGNMENT Ain 1 16 VDD Bout 2 15 Aout Cin 3 14 Bin Dout 4 13 Cout Ein 5 12 Din Fout 6 11 Eout OSCin 7 10 Fin VSS 8 9 OSCout BLOCK DIAGRAM +VDD DATA 4−BIT STATIC SHIFT REGISTER Ain1 SHIFT OSCin7 OSCout9 OSCILLATOR AND TWO−PHASE CLOCK GENERATOR LOAD φ1 φ1 φ2 φ2 φ1 Bin14 IDENTICAL TO ABOVE STAGE Cin3 IDENTICAL TO ABOVE STAGE Din12 IDENTICAL TO ABOVE STAGE Fin10 φ2 φ2 13C out φ1 φ2 φ1 φ2 φ1 φ2 4D out IDENTICAL TO ABOVE STAGE IDENTICAL TO ABOVE STAGE http://onsemi.com 2 VDD = PIN 16 VSS = PIN 8 φ1 φ2 2B out φ1 Ein5 15 Aout 1/2−BIT DELAY 11Eout 6F out MC14490 ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ELECTRICAL CHARACTERISTICS (Voltages Referenced to VSS) − 55_C Characteristic Output Voltage Vin = VDD or 0 Symbol 25_C 125_C VDD Vdc Min Max Min Typ (Note 2) Max Min Max Unit “0” Level VOL 5.0 10 15 − − − 0.05 0.05 0.05 − − − 0 0 0 0.05 0.05 0.05 − − − 0.05 0.05 0.05 Vdc “1” Level VOH 5.0 10 15 4.95 9.95 14.95 − − − 4.95 9.95 14.95 5.0 10 15 − − − 4.95 9.95 14.95 − − − Vdc Input Voltage “0” Level (VO = 4.5 or 0.5 Vdc) (VO = 9.0 or 1.0 Vdc) (VO = 13.5 or 1.5 Vdc) (VO = 0.5 or 4.5 Vdc) “1 Level” (VO = 1.0 or 9.0 Vdc) (VO = 1.5 or 13.5 Vdc) VIL 5.0 10 15 − − − 1.5 3.0 4.0 − − − 2.25 4.50 6.75 1.5 3.0 4.0 − − − 1.5 3.0 4.0 5.0 10 15 3.5 7.0 11 − − − 3.5 7.0 11 2.75 5.50 8.25 − − − 3.5 7.0 11 − − − Vin = 0 or VDD Output Drive Current Oscillator Output (VOH = 2.5 V) (VOH = 4.6 V) (VOH = 9.5 V) (VOH = 13.5 V) Debounce Outputs (VOH = 2.5 V) (VOH = 4.6 V) (VOH = 9.5 V) (VOH = 13.5 V) Oscillator Output (VOL = 0.4 V) (VOL = 0.5 V) (VOL = 1.5 V) Debounce Outputs (VOL = 0.4 V) (VOL = 0.5 V) (VOL = 1.5 V) VIH Vdc IOH Source Sink Vdc mAdc 5.0 5.0 10 15 – 0.6 – 0.12 – 0.23 – 1.4 − − − − – 0.5 – 0.1 – 0.2 – 1.2 – 1.5 – 0.3 – 0.8 – 3.0 − − − − – 0.4 – 0.08 – 0.16 – 1.0 − − − − 5.0 5.0 10 15 – 0.9 – 0.19 – 0.6 1.8 − − − − – 0.75 – 0.16 – 0.5 – 1.5 – 2.2 – 0.46 – 1.2 – 4.5 − − − − – 0.6 – 0.12 – 0.4 – 1.2 − − − − 5.0 10 15 0.36 0.9 4.2 − − − 0.3 0.75 3.5 0.9 2.3 10 − − − 0.24 0.6 2.8 − − − 5.0 10 15 2.6 4.0 12 − − − 2.2 3.3 10 4.0 9.0 35 − − − 1.8 2.7 8.1 − − − IOL mAdc Input Current Debounce Inputs (Vin = VDD) IIH 15 − 2.0 − 0.2 2.0 − 11 mAdc Input Current Oscillator — Pin 7 (Vin = VSS or VDD) Iin 15 − ± 620 − ± 255 ± 400 − ± 250 mAdc Pullup Resistor Source Current Debounce Inputs (Vin = VSS) IIL 5.0 10 15 175 340 505 375 740 1100 140 280 415 190 380 570 255 500 750 70 145 215 225 440 660 mAdc Input Capacitance Cin − − − − 5.0 7.5 − − pF Quiescent Current (Vin = VSS or VDD, Iout = 0 mA) ISS 5.0 10 15 − − − 150 280 840 − − − 40 90 225 100 225 650 − − − 90 180 550 mAdc 2. Data labelled “Typ” is not to be used for design purposes but is intended as an indication of the IC’s potential performance. http://onsemi.com 3 MC14490 ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎ ÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎÎ ÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎ ÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎ SWITCHING CHARACTERISTICS (Note 3) (CL = 50 pF, TA = 25_C) VDD Vdc Min Typ (Note 4) Max Unit 5.0 10 15 − − − 180 90 65 360 180 130 ns 5.0 10 15 − − − 100 50 40 200 100 80 ns tTHL 5.0 10 15 − − − 60 30 20 120 60 40 tPHL 5.0 10 15 − − − 285 120 95 570 240 190 tPLH 5.0 10 15 − − − 370 160 120 740 320 240 Clock Frequency (50% Duly Cycle) (External Clock) fcl 5.0 10 15 − − − 2.8 6 9 1.4 3.0 4.5 MHz Setup Time (See Figure 1) tsu 5.0 10 15 100 80 60 50 40 30 − − − ns Maximum External Clock Input Rise and Fall Time Oscillator Input tr, tf 5.0 10 15 No Limit 5.0 1.5 C ext (in mF) 10 4.5 C ext (in mF) 15 6.5 C ext (in mF) Characteristic Symbol Output Rise Time All Outputs tTLH Output Fall Time Oscillator Output tTHL Debounce Outputs Propagation Delay Time Oscillator Input to Debounce Outputs Oscillator Frequency OSCout Cext ≥ 100 pF* Note: These equations are intended to be a design guide. Laboratory experimentation may be required. Formulas are typically ± 15% of actual frequencies. ns ns fosc, typ Hz 3. The formulas given are for the typical characteristics only at 25_C. 4. Data labelled “Typ” is not to be used for design purposes but is intended as an indication of the IC’s potential performance. *POWER−DOWN CONSIDERATIONS Large values of Cext may cause problems when powering down the MC14490 because of the amount of energy stored in the capacitor. When a system containing this device is powered down, the capacitor may discharge through the input protection diodes at Pin 7 or the parasitic diodes at Pin 9. Current through these internal diodes must be limited to 10 mA, therefore the turn−off time of the power supply must not be faster than t = (VDD − VSS) Cext /(10 mA). For example, If VDD − VSS = 15 V and Cext = 1 mF, the power supply must turn off no faster than t = (15 V) (1 mF)/10 mA = 1.5 ms. This is usually not a problem because power supplies are heavily filtered and cannot discharge at this rate. When a more rapid decrease of the power supply to zero volts occurs, the MC14490 may sustain damage. To avoid this possibility, use external clamping diodes, D1 and D2, connected as shown in Figure 2. Aout VDD 50% OSCin tPLH 50% 0V 90% 10% D1 tr tPHL Aout 90% 10% OSCin Ain 7 OSCin 50% tf 50% 50% Cext VDD tsu VDD D2 VDD 9 OSCout MC14490 0V VDD 0V Figure 1. Switching Waveforms Figure 2. Discharge Protection During Power Down http://onsemi.com 4 MC14490 THEORY OF OPERATION The MC14490 Hex Contact Bounce Eliminator is basically a digital integrator. The circuit can integrate both up and down. This enables the circuit to eliminate bounce on both the leading and trailing edges of the signal, shown in the timing diagram of Figure 3. Each of the six Bounce Eliminators is composed of a 4−1/2−bit register (the integrator) and logic to compare the input with the contents of the shift register, as shown in Figure 4. The shift register requires a series of timing pulses in order to shift the input signal into each shift register location. These timing pulses (the clock signal) are represented in the upper waveform of Figure 3. Each of the six Bounce Eliminator circuits has an internal resistor as shown in Figure 4. A pullup resistor was incorporated rather than a pulldown resistor in order to implement switched ground input signals, such as those coming from relay contacts and push buttons. By switching ground, rather than a power supply lead, system faults (such as shorts to ground on the signal input leads) will not cause excessive currents in the wiring and contacts. Signal lead shorts to ground are much more probable than shorts to a power supply lead. When the relay contact is closed, (see Figure 4) the low level is inverted, and the shift register is loaded with a high on each positive edge of the clock signal. To understand the operation, we assume all bits of the shift register are loaded with lows and the output is at a high level. At clock edge 1 (Figure 3) the input has gone low and a high has been loaded into the first bit or storage location of the shift register. Just after the positive edge of clock 1, the input signal has bounced back to a high. This causes the shift register to be reset to lows in all four bits — thus starting the timing sequence over again. During clock edges 3 to 6 the input signal has stayed low. Thus, a high has been shifted into all four shift register bits and, as shown, the output goes low during the positive edge of clock pulse 6. It should be noted that there is a 3−1/2 to 4−1/2 clock period delay between the clean input signal and output signal. In this example there is a delay of 3.8 clock periods from the beginning of the clean input signal. OSCin OR OSCout 1 2 3 4 5 After some time period of N clock periods, the contact is opened and at N+1 a low is loaded into the first bit. Just after N+1, when the input bounces low, all bits are set to a high. At N+2 nothing happens because the input and output are low and all bits of the shift register are high. At time N+3 and thereafter the input signal is a high, clean signal. At the positive edge of N+6 the output goes high as a result of four lows being shifted into the shift register. Assuming the input signal is long enough to be clocked through the Bounce Eliminator, the output signal will be no longer or shorter than the clean input signal plus or minus one clock period. The amount of time distortion between the input and output signals is a function of the difference in bounce characteristics on the edges of the input signal and the clock frequency. Since most relay contacts have more bounce when making as compared to breaking, the overall delay, counting bounce period, will be greater on the leading edge of the input signal than on the trailing edge. Thus, the output signal will be shorter than the input signal — if the leading edge bounce is included in the overall timing calculation. The only requirement on the clock frequency in order to obtain a bounce free output signal is that four clock periods do not occur while the input signal is in a false state. Referring to Figure 3, a false state is seen to occur three times at the beginning of the input signal. The input signal goes low three times before it finally settles down to a valid low state. The first three low pulses are referred to as false states. If the user has an available clock signal of the proper frequency, it may be used by connecting it to the oscillator input (pin 7). However, if an external clock is not available the user can place a small capacitor across the oscillator input and output pins in order to start up an internal clock source (as shown in Figure 4). The clock signal at the oscillator output pin may then be used to clock other MC14490 Bounce Eliminator packages. With the use of the MC14490, a large number of signals can be cleaned up, with the requirement of only one small capacitor external to the Hex Bounce Eliminator packages. 6 N+1 N+3 N+5 INPUT OUTPUT CONTACT OPEN CONTACT BOUNCING CONTACT CLOSED (VALID TRUE SIGNAL) CONTACT OPEN CONTACT BOUNCING Figure 3. Timing Diagram http://onsemi.com 5 N+7 MC14490 +VDD Ain 1 FORM A" CONTACT OSCin 7 Cext OSCout 9 PULLUP RESISTOR (INTERNAL) DATA 4−BIT STATIC SHIFT REGISTER SHIFT OSCILLATOR AND TWO−PHASE CLOCK GENERATOR 1/2 BIT DELAY LOAD 15 Aout φ1 φ2 φ1 φ1 φ2 φ2 Figure 4. Typical “Form A” Contact Debounce Circuit (Only One Debouncer Shown) OPERATING CHARACTERISTICS The single most important characteristic of the MC14490 is that it works with a single signal lead as an input, making it directly compatible with mechanical contacts (Form A and B). The circuit has a built−in pullup resistor on each input. The worst case value of the pullup resistor (determined from the Electrical Characteristics table) is used to calculate the contact wetting current. If more contact current is required, an external resistor may be connected between VDD and the input. Because of the built−in pullup resistors, the inputs cannot be driven with a single standard CMOS gate when VDD is below 5 V. At this voltage, the input should be driven with Cext OSCin FROM CONTACTS 7 9 MC14490 paralleled standard gates or by the MC14049 or MC14050 buffers. The clock input circuit (pin 7) has Schmitt trigger shaping such that proper clocking will occur even with very slow clock edges, eliminating any need for clock preshaping. In addition, other MC14490 oscillator inputs can be driven from a single oscillator output buffered by an MC14050 (see Figure 5). Up to six MC14490s may be driven by a single buffer. The MC14490 is TTL compatible on both the inputs and the outputs. When VDD is at 4.5 V, the buffered outputs can sink 1.6 mA at 0.4 V. The inputs can be driven with TTL as a result of the internal input pullup resistors. OSCin7 1/6 MC14050 FROM CONTACTS OSCout TO SYSTEM LOGIC NO CONNECTION 9OSC out TO SYSTEM LOGIC MC14490 NO CONNECTION 9OSC out OSCin7 FROM CONTACTS MC14490 Figure 5. Typical Single Oscillator Debounce System http://onsemi.com 6 TO SYSTEM LOGIC MC14490 TYPICAL APPLICATIONS ASYMMETRICAL TIMING MULTIPLE TIMING SIGNALS In applications where different leading and trailing edge delays are required (such as a fast attack/slow release timer.) Clocks of different frequencies can be gated into the MC14490 as shown in Figure 6. In order to produce a slow attack/fast release circuit leads A and B should be interchanged. The clock out lead can then be used to feed clock signals to the other MC14490 packages where the asymmetrical input/output timing is required. As shown in Figure 8, the Bounce Eliminator circuits can be connected in series. In this configuration each output is delayed by four clock periods relative to its respective input. This configuration may be used to generate multiple timing signals such as a delay line, for programming other timing operations. One application of the above is shown in Figure 9, where it is required to have a single pulse output for a single operation (make) of the push button or relay contact. This only requires the series connection of two Bounce Eliminator circuits, one inverter, and one NOR gate in order to generate the signal AB as shown in Figures 9 and 10. The signal AB is four clock periods in length. If the inverter is switched to the A output, the pulse AB will be generated upon release or break of the contact. With the use of a few additional parts many different pulses and waveshapes may be generated. IN OSCin OUT MC14490 OSCout MC14011B 1 A EXTERNAL CLOCK Ain B fC ÷N fC/N 14 Bin B.E. 1 B.E. 2 15 2 Aout Bout Figure 6. Fast Attack/Slow Release Circuit 3 LATCHED OUTPUT Cin The contents of the Bounce Eliminator can be latched by using several extra gates as shown in Figure 7. If the latch lead is high the clock will be stopped when the output goes low. This will hold the output low even though the input has returned to the high state. Any time the clock is stopped the outputs will be representative of the input signal four clock periods earlier. 12 Din 5 Ein IN B.E. 4 B.E. 5 13 4 11 Cout Dout Eout OUT 10 OSCin B.E. 3 MC14490 Fin B.E. 6 6 Fout OSCout MC14011B CLOCK OSCin LATCH = 1 UNLATCH = 0 7 CLOCK 9 OSCout Figure 8. Multiple Timing Circuit Connections Figure 7. Latched Output Circuit http://onsemi.com 7 MC14490 IN A OUT BE 1 A IN OUT BE 2 B AB B A ≡ ACTIVE LOW B ≡ ACTIVE LOW Figure 9. Single Pulse Output Circuit OSCin OR OSCout INPUT A B C D E F AB AB Figure 10. Multiple Output Signal Timing Diagram http://onsemi.com 8 MC14490 ORDERING INFORMATION Device Package MC14490DW SOIC−16 MC14490DWG SOIC−16 (Pb−Free) MC14490DWR2 SOIC−16 MC14490DWR2G SOIC−16 (Pb−Free) MC14490F SOEIAJ−16 MC14490FG SOEIAJ−16 (Pb−Free) MC14490FEL SOEIAJ−16 MC14490FELG SOEIAJ−16 (Pb−Free) MC14490P PDIP−16 MC14490PG PDIP−16 (Pb−Free) Shipping † 47 Units / Rail 1000 / Tape & Reel 50 Units / Rail 2000 Units / Tape & Reel 25 Units / Rail †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. http://onsemi.com 9 MC14490 PACKAGE DIMENSIONS PDIP−16 CASE 648−08 ISSUE T NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. DIMENSION L TO CENTER OF LEADS WHEN FORMED PARALLEL. 4. DIMENSION B DOES NOT INCLUDE MOLD FLASH. 5. ROUNDED CORNERS OPTIONAL. −A− 16 9 1 8 B F C L S −T− SEATING PLANE K H G D M J 16 PL 0.25 (0.010) T A M M DIM A B C D F G H J K L M S INCHES MIN MAX 0.740 0.770 0.250 0.270 0.145 0.175 0.015 0.021 0.040 0.70 0.100 BSC 0.050 BSC 0.008 0.015 0.110 0.130 0.295 0.305 0_ 10 _ 0.020 0.040 MILLIMETERS MIN MAX 18.80 19.55 6.35 6.85 3.69 4.44 0.39 0.53 1.02 1.77 2.54 BSC 1.27 BSC 0.21 0.38 2.80 3.30 7.50 7.74 0_ 10 _ 0.51 1.01 SO−16 WB CASE 751G−03 ISSUE C A D 9 h X 45 _ E 0.25 1 16X M 14X e T A S B S L A 0.25 B B NOTES: 1. DIMENSIONS ARE IN MILLIMETERS. 2. INTERPRET DIMENSIONS AND TOLERANCES PER ASME Y14.5M, 1994. 3. DIMENSIONS D AND E DO NOT INLCUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.15 PER SIDE. 5. DIMENSION B DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.13 TOTAL IN EXCESS OF THE B DIMENSION AT MAXIMUM MATERIAL CONDITION. MILLIMETERS DIM MIN MAX A 2.35 2.65 A1 0.10 0.25 B 0.35 0.49 C 0.23 0.32 D 10.15 10.45 E 7.40 7.60 e 1.27 BSC H 10.05 10.55 h 0.25 0.75 L 0.50 0.90 q 0_ 7_ 8 A1 H 8X M B M 16 q SEATING PLANE T C http://onsemi.com 10 MC14490 PACKAGE DIMENSIONS SOEIAJ−16 CASE 966−01 ISSUE A 16 LE 9 Q1 M_ E HE 1 8 L DETAIL P Z D e VIEW P A DIM A A1 b c D E e HE L LE M Q1 Z A1 b 0.13 (0.005) c NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSIONS D AND E DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS AND ARE MEASURED AT THE PARTING LINE. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.15 (0.006) PER SIDE. 4. TERMINAL NUMBERS ARE SHOWN FOR REFERENCE ONLY. 5. THE LEAD WIDTH DIMENSION (b) DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.08 (0.003) TOTAL IN EXCESS OF THE LEAD WIDTH DIMENSION AT MAXIMUM MATERIAL CONDITION. DAMBAR CANNOT BE LOCATED ON THE LOWER RADIUS OR THE FOOT. MINIMUM SPACE BETWEEN PROTRUSIONS AND ADJACENT LEAD TO BE 0.46 ( 0.018). M 0.10 (0.004) MILLIMETERS MIN MAX −−− 2.05 0.05 0.20 0.35 0.50 0.10 0.20 9.90 10.50 5.10 5.45 1.27 BSC 7.40 8.20 0.50 0.85 1.10 1.50 10 _ 0_ 0.70 0.90 −−− 0.78 INCHES MIN MAX −−− 0.081 0.002 0.008 0.014 0.020 0.007 0.011 0.390 0.413 0.201 0.215 0.050 BSC 0.291 0.323 0.020 0.033 0.043 0.059 10 _ 0_ 0.028 0.035 −−− 0.031 ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. 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