INTEGRATED CIRCUITS DATA SHEET For a complete data sheet, please also download: • The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications • The IC06 74HC/HCT/HCU/HCMOS Logic Package Information • The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines 74HC/HCT4538 Dual retriggerable precision monostable multivibrator Product specification File under Integrated Circuits, IC06 September 1993 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 trigger/retrigger input (nA1) , an overriding active LOW direct reset input (nRD), an output (nQ) and its complement (nQ), and two pins (nCTC and nRCTC) for connecting the external timing components Ct and Rt. Typical pulse width variation over temperature range is ± 0.2%. FEATURES • Separate reset inputs • Triggering from leading or trailing edge • Output capability: standard • ICC category: MSI The “4538” may be triggered by either the positive or the negative edges of the input pulse. The duration and accuracy of the output pulse are determined by the external timing components Ct and Rt. The output pulse width (T) is equal to 0.7 × Rt × Ct. The linear design techniques guarantee precise control of the output pulse width. • Power-on reset on-chip GENERAL DESCRIPTION The 74HC/HCT4538 are high-speed Si-gate CMOS devices and are pin compatible with “4538” of the “4000B” series. They are specified in compliance with JEDEC standard no. 7A. A LOW level at nRD terminates the output pulse immediately. The 74HC/HCT4538 are dual retriggerable-resettable monostable multivibrators. Each multivibrator has an active LOW trigger/retrigger input (nA0), an active HIGH Schmitt-trigger action in the trigger inputs makes the circuit highly tolerant to slower rise and fall times. QUICK REFERENCE DATA GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns TYPICAL SYMBOL PARAMETER CONDITIONS UNIT HC CL = 15 pF; VCC = 5 V HCT tPHL/ tPLH propagation delay nA0, nA1 to nQ, nQ 27 30 ns CI input capacitance 3.5 3.5 pF CPD power dissipation capacitance per multivibrator notes 1 and 2 136 138 pF Notes 1. CPD is used to determine the dynamic power dissipation (PD in µW): PD = CPD × VCC2 × fi + ∑ (CL × VCC2 × fo) + + 0.48 × CEXT × VCC2 × fo + D × 0.8 × VCC where: fi = input frequency in MHz fo = output frequency in MHz ∑ (CL × VCC2 × fo) = sum of outputs CL = output load capacitance in pF VCC = supply voltage in V D = duty factor in % CEXT = timing capacitance in pF 2. For HC the condition is VI = GND to VCC For HCT the condition is VI = GND to VCC − 1.5 V ORDERING INFORMATION See “74HC/HCT/HCU/HCMOS Logic Package Information”. September 1993 2 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 PIN DESCRIPTION PIN NO. SYMBOL NAME AND FUNCTION 1, 15 1CTC, 2CTC external capacitor connections 2, 14 1RCTC, 2RCTC external resistor/capacitor connections 3, 13 1RD, 2RD direct reset inputs (active LOW) 4, 12 1A1, 2A1 trigger inputs (LOW-to-HIGH, edge-triggered) 5, 11 1A0, 2A0 trigger inputs (HIGH-to-LOW, edge-triggered) 6, 10 1Q, 2Q pulse outputs 7, 9 1Q, 2Q complementary pulse outputs 8 GND ground (0 V) 16 VCC positive supply voltage Fig.1 Pin configuration. September 1993 Fig.2 Logic symbol. 3 Fig.3 IEC logic symbol. Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 FUNCTION TABLE INPUTS OUTPUTS nA0 nA1 nRD ↓ L H H ↑ H X X L nQ nQ L H Notes 1. H L X ↑ ↓ Fig.4 Functional diagram. = HIGH voltage level = LOW voltage level = don’t care = LOW-to-HIGH transition = HIGH-to-LOW transition = one HIGH level output pulse = one LOW level output pulse (1) Connect CTC (pins 1 and 15) to GND (pin 8). Fig.5 Connection of the external timing components Rt and Ct. (1) Positive edge triggering. (2) Positive edge retriggering (pulse lengthening). (3) (4) (5) (6) Negative edge triggering. Reset (pulse shortening). Vref1 and Vref2 are internal reference voltages. T = 0.7 × Rt × Ct (see also Fig.5). Fig.6 Timing diagram. September 1993 4 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 nA1 nA0 VCC power - on reset VCC nRC TC Vref1 enable nQ nC TC GND nQ nR D V ref2 enable handbook, full pagewidth MBA338 Fig.7 Logic diagram (Vref1 and Vref2 are internal reference voltages). September 1993 5 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 DC CHARACTERISTICS FOR 74HC For the DC characteristics see “74HC/HCT/HCU/HCMOS Logic Family Specifications”. Output capability: standard ICC category: MSI AC CHARACTERISTICS FOR 74HC GND = 0 V; tr = tf = 6 ns; CL = 50 pF Tamb (°C) TEST CONDITIONS 74HC SYMBOL PARAMETER +25 min. typ. −40 to +85 max. min. max. −40 to +125 min. UNIT V CC (V) OTHER max. tPLH propagation delay nA0, nA1 to nQ 85 31 25 265 53 45 330 66 56 400 80 68 ns 2.0 4.5 6.0 Fig.8 tPHL propagation delay nA0, nA1 to nQ 83 30 24 265 53 45 330 66 56 400 80 68 ns 2.0 4.5 6.0 Fig.8 tPHL propagation delay nRD to nQ 80 29 23 265 53 45 330 66 56 400 80 68 ns 2.0 4.5 6.0 Fig.8 tPLH propagation delay nRD to nQ 83 30 24 265 53 45 340 68 58 400 80 68 ns 2.0 4.5 6.0 Fig.8 tTHL/ tTLH output transition time 19 7 6 75 15 13 95 19 16 110 22 19 ns 2.0 4.5 6.0 Fig.8 tW nA0 pulse width LOW 80 16 14 17 6 5 100 20 17 120 24 20 ns 2.0 4.5 6.0 Fig.8 tW nA1 pulse width HIGH 80 16 14 17 6 5 100 20 17 120 24 20 ns 2.0 4.5 6.0 Fig.8 tW nRD pulse width LOW 80 16 14 19 7 6 100 20 17 120 24 20 ns 2.0 4.5 6.0 Fig.8 tW nQ, nQ pulse width HIGH or LOW 0.63 0.70 0.602 0.798 0.595 0.805 ms 5.0 Fig.8; Rt = 10 kΩ; Ct = 0.1 µF trem removal time RD to nA0, nA1 35 7 6 45 9 8 ns 2.0 4.5 6.0 Fig.8 September 1993 6 2 2 0.77 6 55 11 9 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 Tamb (°C) TEST CONDITIONS 74HC SYMBOL PARAMETER +25 min. trt retrigger time nA0, nA1 − − − REXT external timing resistor 10 2 CEXT external timing capacitor typ. −40 to +85 max. min. − − − 455+X 80+X 55+X max. −40 to +125 min. UNIT V CC (V) OTHER max. − − − 1000 1000 no limits ns 2.0 4.5 6.0 kΩ 2.0 5.0 pF 5.0 Fig.8 X = CEXT / (4.5 × VCC) NON-STANDARD DC CHARACTERISTICS FOR 74HC Voltages are referenced to GND (ground = 0 V) Tamb (°C) TEST CONDITIONS 74HC SYMBOL PARAMETER +25 −40 to +85 −40 to +125 UNIT VCC (V) µA 6.0 VI (V) OTHER min. typ max. min. max. min. max. ±II input leakage current nRCEXT 0.5 5.0 10.0 Note 1. This measurement can only be carried out after a trigger pulse is applied. September 1993 7 2.0 VCC or GND; or note 1 GND Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 DC CHARACTERISTICS FOR 74HCT For the DC characteristics see “74HC/HCT/HCU/HCMOS Logic Family Specifications”. Output capability: standard ICC category: MSI Note to HCT types The value of additional quiescent supply current (∆ICC) for a unit load of 1 is given in the family specifications. To determine ∆ICC per input, multiply this value by the unit load coefficient shown in the table below. INPUT UNIT LOAD COEFFICIENT nA0, nA1 nRD 0.50 0.65 AC CHARACTERISTICS FOR 74HCT GND = 0 V; tr = tf = 6 ns; CL = 50 pF Tamb (°C) TEST CONDITIONS 74HCT SYMBOL PARAMETER +25 min. typ. max. −40 to +85 −40 to +125 min. min. max. UNIT V OTHER CC (V) max. tPLH propagation delay nA0, nA1 to nQ 35 60 75 90 ns 4.5 Fig.8 tPHL propagation delay nA0, nA1 to nQ 35 60 75 90 ns 4.5 Fig.8 tPHL propagation delay nRD to nQ 35 60 75 90 ns 4.5 Fig.8 tPLH propagation delay nRD to nQ 35 60 75 90 ns 4.5 Fig.8 tTHL/ tTLH output transition time 7 15 19 21 ns 4.5 Fig.8 tW nA0 pulse width LOW 20 11 25 30 ns 4.5 Fig.8 tW nA1 pulse width HIGH 16 5 20 24 ns 4.5 Fig.8 tW nRD pulse width LOW 20 11 25 30 ns 4.5 Fig.8 tW nQ, nQ pulse width HIGH or LOW 0.63 0.70 0.602 0.798 0.595 0.805 ms 5.0 Fig.8; Rt = 10 kΩ; Ct = 0.1 µF trem removal time RD to nA0, nA1 7 2 9 11 ns 4.5 Fig.8 trt retrigger time nA0, nA1 − 80+X − − ns 4.5 Fig.8 X = CEXT / (4.5 × VCC) REXT external timing resistor 2 kΩ 5.0 CEXT external timing capacitor pF 5.0 September 1993 0.77 1000 no limits 8 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 NON-STANDARD DC CHARACTERISTICS FOR 74HCT Voltages are referenced to GND (ground = 0 V) Tamb (°C) TEST CONDITIONS 74HCT SYMBOL PARAMETER +25 −40 to +85 −40 to +125 UNIT V CC (V) VI (V) OTHER min. typ max. min. max. min. max. ±II input leakage current nRCEXT 0.5 5.0 10.0 µA 5.5 2.0 VCC or GND; or note 1 GND Note 1. This measurement can only be carried out after a trigger pulse is applied. AC WAVEFORMS (1) HC : VM = 50%; VI = GND to VCC. HCT: VM = 1.3 V; VI = GND to 3 V. Fig.8 Waveforms showing the input (nA1, nA0, nRD) to output (nQ, nQ) propagation delays, the output transition times, the input and output pulse widths, the removal time from direct reset (nRD) to input (nA1, nA0), and the input retrigger time. September 1993 9 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 APPLICATION INFORMATION (a) (b) Fig.9 Retriggerable monostable circuitry. (a) rising-edge triggered; (b) falling-edge triggered. (a) (b) Fig.10 Non-retriggerable monostable circuitry. (a) rising-edge triggered; (b) falling-edge triggered. September 1993 10 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 Power-down considerations A large capacitor (CX) may cause problems when powering-down the monostable due to the energy stored in this capacitor. When a system containing this device is powered-down or a rapid decrease of VCC to zero occurs, the monostable may sustain damage, due to the capacitor discharging through the input protection diodes. To avoid this possibility, use a damping diode (DX) preferably a germanium or Schottky type diode able to withstand large current surges and connect as shown in Fig.11. Fig.11 Power-down protection circuit. Fig.12 Typical pulse width accuracy versus external capacitance; VCC = 4.5 V; Tamb = 25 °C. Fig.13 Typical pulse width accuracy versus external resistance; VCC = 4.5 V; Tamb = 25 °C. September 1993 11 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 Fig.14 Typical pulse width accuracy versus external capacitance; REXT = 10 kΩ; VCC = 4.5 V; Tamb = 25 °C. Fig.15 Typical pulse width accuracy versus power supply; CEXT = 1 nF; Tamb = 25 °C. Fig.16 Typical pulse width accuracy versus power supply; CEXT = 100 nF; Tamb = 25 °C. September 1993 12 Philips Semiconductors Product specification Dual retriggerable precision monostable multivibrator 74HC/HCT4538 Fig.17 Typical pulse width accuracy versus temperature; CEXT = 1 nF; VCC = 4.5 V. Fig.18 Typical pulse width accuracy versus temperature; CEXT = 1 µF; VCC = 4.5 V. PACKAGE OUTLINES See “74HC/HCT/HCU/HCMOS Logic Package Outlines”. September 1993 13