74HC-HCT85 SYC | Alldatasheet

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Technical content

Product specification File under Integrated Circuits, IC06 December 1990 74HC/HCT85 4-bit magnitude comparator www.sycelectronica.com.ar

Philips Semiconductors Product specification 4-bit magnitude comparator 74HC/HCT85

FEATURES

  • Serial or parallel expansion without extra gating
  • Magnitude comparison of any binary words
  • Output capability: standard
  • ICC category: MSI GENERAL DESCRIPTION The 74HC/HCT85 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. The 74HC/HCT85 are 4-bit magnitude comparators that can be expanded to almost any length. They perform comparison of two 4-bit binary, BCD or other monotonic codes and present the three possible magnitude results at the outputs (Q A>B, QA=B and QA<B). The 4-bit inputs are weighted (A0 to A3 and B0 to B3), where A3 and B3 are the most significant bits. The operation of the “85” is described in the function table, showing all possible logic conditions. The upper part of the table describes the normal operation under all conditions that will occur in a single device or in a series expansion scheme. In the upper part of the table the three outputs are mutually exclusive. In the lower part of the table, the outputs reflect the feed forward conditions that exist in the parallel expansion scheme. For proper compare operation the expander inputs (I A>B, IA=B and IA<B) to the least significant position must be connected as follows: IA<B =IA>B = = LOW and IA=B = HIGH. For words greater than 4-bits, units can be cascaded by connecting outputs Q A<B, QA>Β and QA=B to the corresponding inputs of the significant comparator. QUICK REFERENCE DATA GND = 0 V; Tamb =2 5°C; tr =tf= 6 ns Notes 1. C PD is used to determine the dynamic power dissipation (PD inµW): PD =C PD × VCC 2 × fi+ ∑ (CL × VCC 2 ×fo) where: fi= input frequency in MHz fo = output frequency in MHz ∑ (CL × VCC 2 × fo) = sum of outputs C L = output load capacitance in pF VCC = supply voltage in V 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”. SYMBOL PARAMETER CONDITIONS TYPICAL UNIT HC HCT tPHL/ tPLH propagation delay C L = 15 pF; VCC =5 V An, Bn to QA>B, QA<B 20 22 ns An, Bn to QA=B 18 20 ns IA<B,, IA=B , IA>B to QA<B, QA>B 15 15 ns IA=B to QA=B 11 15 ns C I input capacitance 3.5 3.5 pF C PD power dissipation capacitance per package notes 1 and 2 18 20 pF www.sycelectronica.com.ar

Philips Semiconductors Product specification 4-bit magnitude comparator 74HC/HCT85 PIN DESCRIPTION PIN NO. SYMBOL NAME AND FUNCTION 2I A<B A < B expansion input 3I A=B A = B expansion input 4I A>B A > B expansion input 5Q A>B A > B output 6Q A=B A = B output 7Q A<B A < B output

8 GND ground (0 V)

9, 11, 14, 1, B 0 to B3 word B inputs 10, 12, 13, 15 A 0 to A3 word A inputs

16 V CC positive supply voltage

Fig.1 Pin configuration. Fig.2 Logic symbol. Fig.3 IEC logic symbol. www.sycelectronica.com.ar

Philips Semiconductors Product specification 4-bit magnitude comparator 74HC/HCT85

APPLICATIONS

  • Process controllers
  • Servo-motor control FUNCTION TABLE Notes 1. H = HIGH voltage level L = LOW voltage level X = don’t care COMPARING INPUTS CASCADING INPUTS OUTPUTS A 3, B3 A 2, B2 A 1, B1 A 0, B0 IA >B IA <B IA=B Q A >B Q A <B Q A=B A3>B3 A3<B3 A3=B3 A3=B3 X X A 2>B2 A2<B2 X X X X X X X X X X X X X X X X X X X X H L H L L H L H L L L L A 3=B3 A3=B3 A3=B3 A3=B3 A2=B 2 A2=B 2 A2=B 2 A2=B 2 A1>B1 A1<B1 A1=B 1 A1=B 1 X X A 0>B0 A0<B0 X X X X X X X X X X X X H L H L L H L H L L L L A 3=B3 A3=B3 A3=B3 A2=B 2 A2=B 2 A2=B 2 A1=B 1 A1=B 1 A1=B 1 A0=B 0 A0=B 0 A0=B 0 H L L L H L L L H H L L L H L L L H A 3=B3 A3=B3 A3=B3 A2=B 2 A2=B 2 A2=B 2 A1=B 1 A1=B 1 A1=B 1 A0=B 0 A0=B 0 A0=B 0 X H L X H L H L L L L H L L H H L L Fig.4 Functional diagram. www.sycelectronica.com.ar

Philips Semiconductors Product specification 4-bit magnitude comparator 74HC/HCT85 Fig.5 Logic diagram. www.sycelectronica.com.ar

Philips Semiconductors Product specification 4-bit magnitude comparator 74HC/HCT85 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 SYMBOL PARAMETER Tamb (°C) TEST CONDITIONS 74HC UNIT VCC (V) WAVEFORMS+25 −40 to+85 −40 to+125 tPHL / tPLH propagation delay An, Bn to QA>B or QA<B 195 245 295 ns 2.0 4.5 6.0 Fig.6 t PHL / tPLH propagation delay An, Bn to QA=B 175 220 265 ns 2.0 4.5 6.0 Fig.6 t PHL / tPLH propagation delay IA<B, IA=B , IA>B to Q A<B, QA>B 140 175 210 ns 2.0 4.5 6.0 Fig.6 t PHL / tPLH propagation delay IA=B to QA=B 120 150 180 ns 2.0 4.5 6.0 Fig.6 t THL / tTLH output transition time 19 110 ns 2.0 4.5 6.0 Fig.6 www.sycelectronica.com.ar

Philips Semiconductors Product specification 4-bit magnitude comparator 74HC/HCT85 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 (ΔICC ) for a unit load of 1 is given in the family specifications. To determineΔICC per input, multiply this value by the unit load coefficient shown in the table below. AC CHARACTERISTICS FOR 74HCT GND = 0 V; tr =tf= 6 ns; CL = 50 pF INPUT UNIT LOAD COEFFICIENT IA<B IA>B IA=B An, Bn 1.00 1.00 1.50 1.50 SYMBOL PARAMETER T amb (°C) TEST CONDITIONS 74HCT UNIT VCC (V) WAVEFORMS+25 −40 to+85 −40 to+125 tPHL / tPLH propagation delay An, Bn to QA>B or QA<B 26 44 55 66 ns 4.5 Fig.6 tPHL / tPLH propagation delay An, Bn to QA=B 24 40 50 60 ns 4.5 Fig.6 tPHL / tPLH propagation delay IA<B, IA=B , IA>B to Q A<B, QA>B 18 31 39 47 ns 4.5 Fig.6 tPHL / tPLH propagation delay IA=B to QA=B 18 31 39 47 ns 4.5 Fig.6 tTHL / tTLH output transition time 7 15 19 22 ns 4.5 Fig.6 www.sycelectronica.com.ar

Philips Semiconductors Product specification 4-bit magnitude comparator 74HC/HCT85 AC WAVEFORMS

APPLICATION INFORMATION

Fig.6 Waveforms showing the word A inputs (An), word B inputs (Bn) and expansion inputs (In) to the outputs (Qn) propagation delays and the output transition times. (1) HC : VM = 50%; VI= GND to VCC . HCT: VM = 1.3 V; VI= GND to 3 V. Fig.7 Series cascading; comparing 12-bit words. www.sycelectronica.com.ar

Philips Semiconductors Product specification 4-bit magnitude comparator 74HC/HCT85 PACKAGE OUTLINES See “74HC/HCT/HCU/HCMOS Logic Package Outlines”. Fig.8 Parallel cascading; comparing 12-bit words. www.sycelectronica.com.ar