SGS-THOMSON M5 4HC4 5 3 8 M7 4HC4 5 3 8 handbook
Contents
1. 5 9 a 9 B S Sli JA Go Cx 0 1 uF Rx 10KQ 3 0 67 0 0 67 0 8 Output Pulse Width Error Between Circuits Minimum Pulse Width CLOCK Minimum Pulse Width CLEAR Minimum Clear Removal Time Minimum Retrigger Time Cin Input Capacitance 5 10 10 10 pF Power Dissipation 70 C pF apacitance Cep is defined as the value ofthe IC s internal equivalent capadtance which is calculated from the operating current consumption without load Refer to Test Circuit Average operting current can be obtained by the following equation Icc opr Cep lcc e Duty 100 Icc 2 per circuit lcc Active Supply Current Duty 7 14 M54 M74HC4538 TEST CIRCUIT Icc Opr Output Pulse Width Constant K Supply Voltage INPUT WAVEFORM IS THE AS THAT IN CASE OF SWITCHING CHARACTERISTICS TEST twour Cx Characteristics Typ SICK 1000pF n a a 4 BR 3 GE amp 1a CX pF 0 1 2 3 4 5 6 vec Y 8 14 755 ky MICROELECTRONICS M54 M74HC4538 SWITCHING CHARACTERISTICS TEST WAVEFORM 10147 4 SGS THOMSON NG 74 MICROELECTRONICS M54 M74HC4538 Plastic DIP16 0 25 P001C 10 14 M54 M74HC4538 Ceramic DIP16 1 sy 65 THOMSON2. Direct Reset Inputs Active Trigger Inputs LOW to HIGH Edge Triggered Trigger Inputs HIGH to LOW Edge Triggered Q1 Q2 Complementary Pulse Outputs GND Ground 0V Positive Supply Voltage 4 14 SGS THOMSON 74 HICROELECTRO Fio LI OUTPUT ENABLE H INHIBIT H INHIBIT LJ OUTPUT ENABLE H INHIBIT Vcc OUTPUT 8 112110 RIGS M54 M74HC4538 ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit V Supply Voltage 0 5 to 7 V DC Input Voltage 0 5 to Vcc 4 0 5 DC Output Diode Current 20 DC Output Source Sink Current Per Output Pin t25 CC IK K V V 2 V mA i i mA lcc or DC Vcc or Ground Current 50 mA Pp Power Dissipation 500 mW Storage Temperature 65 to 150 300 C TL Lead Temperature 10 sec Absolute Maximum Ratings are those values beyond which damage to the device may occu Functional operation under these condition is notimplied 500 mW 65 C derate to 300 mW by 10mW C 65 C to 85 C RECOMMENDED OPERATING CONDITIONS Symbol Parameter Value Unit Voc Supply Voltage 2106 V Vo Output Voltage 0 to Vcc V Top Operating Temperature M54HC Series 55 to 4125 M74HC Series 40 to 85 0 to 1000 0 to 500 0 to 400 Cx External Capacitor NO LIMITATION Rx External Resistor Veco lt 3 V 5K to 1M Vcc gt 3V 1K to 1M The maximum
3. allowable values of Cx and Rx are a function of leakage of capacitor Cx the leakage of device and leakage due to the board layout and surface resistance Susceptibility to extemally induced noise may occur for Rx gt 1MQ Input Rise and Fall Time CLR only 2 4 5 V Q sy 565 5 A 74 MICROELECTRONICS M54 M74HC4538 DC SPECIFICATIONS Test Conditions Parameter Ta 25 C 40 to 85 C 55 to 125 C 54HC and 74HC 74HC 54HC Min Max Min Max High Level Input Voltage Low Level Input Voltage High Level Output Voltage Low Level Output Voltage 8 18 60 gt 00 01 0 0 011 00 01 Input Leakage Vi Vcc or GND Current Input Leakage Vi Vcc or GND Current i Rext Cext Quiescent Supply 0 Vi Vcc or GND Current Quiescent Supply 0 Vi Vcc or GND Current pins 2 14 2 gt gt E a gt gt 3 gt O o 3 gt 6 14 Gi M54 M74HC4538 AC ELECTRICAL CHARACTERISTICS CL 50 pF Input tr t 6 ns Test Conditions Value Parameter 25 40 to 85 9 54HC 74HC 74HC Max Output Transition Time Propagation Delay Time_ A B Q Q Propagation Delay Time CD Q Q Output Pulse Width Cx 0 01 uF Rx 10KQ M
4. 4578 M 4538 hv 0 M54HC4538 SGS THOMSON I CIS MICROELECTRONICS DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR HIGH SPEED tpp 25 ns TYP AT Voc 2 5 LOW POWER DISSIPATION STANDBY STATE Icc 4 uA MAX AT Ta 25 C ACTIVE STATE Icc 200 uA TYP AT Vcc 5 HIGH NOISE IMMUNITY VNIH VNiL 28 Vcc OUTPUT DRIVE CAPABILITY 10 LSTTLLOADS BALANCED PROPAGATION DELAYS tPHL WIDE OUTPUT PULSE WIDTH RANGE twour 120 ns 60 s OVER AT Vcc 4 5 V OUTPUT PULSE WIDTH INDEPENDENT FROM TRIGGER INPUT PULSE WIDTH PIN AND FUNCTION COMPATIBLE WITH 4538B DESCRIPTION The M54 74HC4538 is a high speed CMOS DUAL MONOSTABLEMULTIVIBRATOR fabricated in sili con gate C MOS technology lt has the same high speed performance of LSTTL combined with true CMOS low power consumption Each multivibrator features both a negative A and a positive B edge triggered input either of which can be used as an in hibit input Also included is a clear input that when taken low resets the one shot The monostable multivibrators are retriggerable That is they may be triggered reapeatedly while their outputs are gener ating a pulse and the pulse will be extended Pulse width stability over a wide range of temperature and supply is achieved using linear CMOS techniques The output pulse equation is simply PW 0 7 R C where PW is in seconds R in Ohms and C is in Farads All inputs are equipped
5. __ dI 74 MICROELECTRONICS M54 M74HC4538 5016 Narrow M 12 4 Ga SGS THOMSON Yf MICROELECTRONICS M54 M74HC4538 1 1 zt 000 80080000 0n 0 n n n nem sy 65 THOMSON 2 13 4 74 MICROELECTRONICS M54 M74HC4538 Information furnished is believed to be accurate and reliable However SGS THOMSON Microelectronics assumes no responsability for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may results from its use No license is granted by implication or otherwise under any patent or patent rights of SGS THOMSON Microelectronics Specifications mentioned in this publication are subject to change without notice This publication supersedes and replaces all information previously supplied SGS THOMSON Microelectronics products are not authorized for use ascritical componentsin life support devices or systems without express written approval of SGS THOMSON Microelectonics 1994 SGS THOMSON Microelectronics Rights Reserved SGS THOMSON Microelectronics GROUP OF COMPANIES Australia Brazil France Germany Hong Kong Italy Japan Korea Malaysia Malta Morocco The Netherlands Singapore Spain Sweden Switzerland Taiwan Thailand United Kingdom U S A 14 14 SR
6. citor and the delay time in the can be ignored the width of the output pulse tw out is as follows tw our 0 72 Rx RE TRIGGER OPERATION When a second trigger pulse follows the first its ef fect will depend on the state of the multivibrator If the capacitor Cx is being charged the voltage level of Rx Cx external falls to VREFL again and remains high i e the retrigger pulse arrives in a time shorter than the period Rx e Cx seconds the capacitor charging time constant If the second trigger pulse is very close to the initial trigger pulse it is ineffective i e the second trigger must arrive in the capacitor discharge cycle to be ineffective Hence the minimum time for a second trigger to be effective trr Min depends on Vcc and Cx c5 THOMSON MICROELECTRO RIGS M54 M74HC4538 FUNCTIONAL DESCRIPTION continued RESET OPERATION __ CD is normally high If CD is low the trigger is not effective because Q output goes low and trigger control flip flop is reset TRUTH TABLE Also transistor Op is turned on and Cx is charged quicky to Vcc This means if CD input goes low the IC becomes waiting state both in operating and non operating state INPUTS 2 5 B PIN DESCRIPTION PIN SYMBOL NAME AND FUNCTION 1 15 1T1 2T1 External Capacitor Connections 2 14 172 2T2 External Resistor Capacitor Connections D 2CD
7. surge current FUNCTIONAL DESCRIPTION STAND BY STATE The external capacitor Cx is fully charged to Vcc in the stand by state Hence before triggering tran sistor Qp and Qn connected to the Rx Cx node are both turned off The two comparators that control the timing and the two reference voltage sources stop operating The total supply current is therefore only leakage current TRIGGER OPERATION Triggering occurs when 1 st A is low and B has a falling edge 2 nd B is high and A has a rising edge After the multivibrator has been retriggered com parator C1 and C2 start operating and Qn is tumed on Cx then discharges through Qn The voltage at the node Rx Cx external falls When it reaches VrerL the output of comparator C1 becomes low This in turn resets the flip flop and Qn is turned off At this point C1 stops functioning but C2 continues to operate The voltage at R C external beginsto rise with a time constant setby the external components Rx Ox Triggering the multivibrator causes Qto go high after internal delay due to the flip flop and the gate Q re mains high until the voltage at R C external rises again to VrerH Atthis point C2 output goes low and G goes low C2 stops operating That means that after triggering when the voltage at R C external re turns to Vrer4 the multivibrator has returned to its MONOSTABLE STATE In the case where Rx e Cx are large enough and the discharge time of the ca pa
8. with protection circuits against static discharge and transient excess volt age October 1993 Plastic Package Ceramic Package Micro Package Chip Carrier ORDER CODES M54HC4538F1R M74HC4538M1R M74HC4538B1R M74HC4538C1R PIN CONNECTIONS top view INPUTS Qu OUTPUTS Qi 1 NC T No Internal Connection 1 14 M54 M74HC4538 SYSTEM DIAGRAM TIMING CHART twoutttrr 5 10178 1 2 14 SGS THOMSON 74 MICROELECTRONICS BLOCK DIAGRAM 5 10143 Notes 1 Cx Rx Dx are external componerts 2 Dx isa clamping diode M54 M74HC4538 5 10142 The external capacitor is charged to Vcc inthe stand by state i e no trigger When the supply voltage is turned off Cx is discharged mainly through aninternal parasitic diode see figures If Cx is sufficiently large and Vcc decreases rapidy there willbe some possibility of damagng the I C with a surge current or latch up If the voltage supply filter capacitor is large enough and Vcc decrease slowly the surge currert is automatically limited and damage the 1 is avoided The maximum forward current of the parasitic diode is ap proximately 20 mA In cases where is large the time taken for the supply voltage to fall to 0 4 Vcc can be calculated as follows t gt Voc 0 7 CX 20 mA In cases where t is too short an extemal champing diode is required to protect the from the
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SGS THOMSON M5 4HC4 5 3 8 M7 4HC4 5 3 8 handbook