74HC251 PHILIPS | Alldatasheet

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Technical content

Product specification File under Integrated Circuits, IC06 December 1990 INTEGRATED CIRCUITS 74HC/HCT251 8-input multiplexer; 3-state 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

Philips Semiconductors Product specification 8-input multiplexer; 3-state 74HC/HCT251

FEATURES

  • True and complement outputs
  • Both outputs are 3-state for further multiplexer expansion
  • Multifunction capability
  • Permits multiplexing from n-lines to one line
  • Output capability: standard
  • ICC category: MSI GENERAL DESCRIPTION The 74HC/HCT251 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/HCT251 are the logic implementations of single-pole 8-position switches with the state of three select inputs (S 0,S1,S2) controlling the switch positions. Assertion (Y) and negation (Y) outputs are both provided. The output enable input (OE) is active LOW. The logic function provided at the output, when activated, is: Both outputs are in the high impedance OFF-state (Z) when the output enable input is HIGH, allowing multiplexer expansion by tying the outputs. QUICK REFERENCE DATA GND = 0 V; T amb = 25°C; tr = tf= 6 ns Notes 1. C PD is used to determine the dynamic power dissipation (PD inµW): PD = CPD × 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 In to Y 15 19 ns In toY1 7 1 9 n s Sn to Y 20 20 ns Sn toY2 1 2 1 n s C I input capacitance 3.5 3.5 pF C PD power dissipation capacitance per package notes 1 and 2 44 46 pF

Philips Semiconductors Product specification 8-input multiplexer; 3-state 74HC/HCT251 PIN DESCRIPTION PIN NO. SYMBOL NAME AND FUNCTION 4, 3, 2, 1, 15, 14, 13, 12 I 0 to I7 multiplexer inputs

5 Y multiplexer output

Y complementary multiplexer output

7 OE 3-state output enable input (active LOW)

8 GND ground (0 V)

11, 10, 9 S 0,S1,S2 select inputs

16 V CC positive supply voltage

Fig.1 Pin configuration. Fig.2 Logic symbol. Fig.3 IEC logic symbol.

Philips Semiconductors Product specification 8-input multiplexer; 3-state 74HC/HCT251 FUNCTION TABLE Note 1. H = HIGH voltage level L = LOW voltage level X = don’t care Z = high impedance OFF-state INPUTS OUTPUTS OE S 2 S1 S0 I0 I1 I2 I3 I4 I5 I6 I7 YY HXXXXXXXXXXXZZ L L L L L L L L L L L L L L H H L H X X X X L H X X X X 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 L L L L H H H H L L H H X X X X X X X X L H X X X X L H 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 H H H H L L L L L L H H X X X X X X X X X X X X X X X X L H X X X X L H X X X X X X X X H L H L L H L H L L L L H H H H H H H H L L H H X X X X X X X X X X X X X X X X X X X X X X X X L H X X X X L H H L H L L H L H Fig.4 Functional diagram. Fig.5 Logic diagram.

Philips Semiconductors Product specification 8-input multiplexer; 3-state 74HC/HCT251 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) UNIT TEST CONDITIONS 74HC VCC (V) WAVEFORMS +25 −40 to+85 −40 to+125 tPHL / tPLH propagation delay In to Y 170 215 255 ns 2.0 4.5 6.0 Fig.6 t PHL / tPLH propagation delay In toY 175 220 265 ns 2.0 4.5 6.0 Fig.7 t PHL / tPLH propagation delay Sn to Y 205 255 310 ns 2.0 4.5 6.0 Fig.6 t PHL / tPLH propagation delay Sn toY 205 255 310 ns 2.0 4.5 6.0 Fig.7 t PZH / tPZL 3-state output enable time OE to Y,Y 140 175 210 ns 2.0 4.5 6.0 Fig.7 t PHZ / tPLZ 3-state output disable time OE to Y,Y 140 170 210 ns 2.0 4.5 6.0 Fig.7 t THL / tTLH output transition time 19 110 ns 2.0 4.5 6.0 Figs 6 and 7

Philips Semiconductors Product specification 8-input multiplexer; 3-state 74HC/HCT251 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 HCT GND = 0 V; tr = tf= 6 ns; CL = 50 pF INPUT UNIT LOAD COEFFICIENT In S1,S2 OE 1.00 1.50 1.50 1.50 SYMBOL PARAMETER T amb (°C) UNIT TEST CONDITIONS 74HCT VCC (V) WAVEFORMS +25 −40 to+85 −40 to+125 tPHL / tPLH propagation delay In to Y 22 35 44 53 ns 4.5 Fig.6 tPHL / tPLH propagation delay In toY 22 35 44 53 ns 4.5 Fig.7 tPHL / tPLH propagation delay Sn to Y 24 44 55 66 ns 4.5 Fig.6 tPHL / tPLH propagation delay Sn toY 25 44 55 66 ns 4.5 Fig.7 tPZH / tPZL 3-state output enable time OE to Y,Y 13 28 35 42 ns 4.5 Fig.7 tPHZ / tPLZ 3-state output disable time OE to Y,Y 14 28 35 42 ns 4.5 Fig.7 tTHL / tTLH output transition time 7 15 19 22 ns 4.5 Figs 6 and 7

Philips Semiconductors Product specification 8-input multiplexer; 3-state 74HC/HCT251 AC WAVEFORMS PACKAGE OUTLINES See “74HC/HCT/HCU/HCMOS Logic Package Outlines”. Fig.6 Waveforms showing the multiplexer input (In) and select input (Sn) to output (Y) propagation delays and the output transition times. (1) HC : VM = 50%; VI= GND to VCC . HCT: VM = 1.3V; VI= GND to 3 V. Fig.7 Waveforms showing the multiplexer input (In) and select input (Sn) to output (Y) propagation delays and the output transition times. (1) HC : VM = 50%; VI= GND to VCC . HCT: VM = 1.3V; VI= GND to 3 V. Fig.8 Waveforms showing the 3-state enable and disable times. (1) HC : VM = 50%; VI= GND to VCC . HCT: VM = 1.3V; VI= GND to 3 V.