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Philips Semiconductors Product specification 8-input multiplexer (3-State) 74F251A FEATURES * High speed 8-to-1 multiplexing * On chip decoding * Multifunction capability * Inverting and Non-Inverting outputs * Both outputs are 3-State for further multiplexer expansion DESCRIPTION The 74F251A is a logic implementation of a single 8-position switch with the switch position controlled by the state of three Select (S0, S1, S2) inputs. True (Y) and complementary (Y) outputs are both provided. The output enable (OE) is active Low. When OE is High, both outputs are in High impedance state, allowing multiple output connections to a common bus without driving nor loading the bus significantly. All but one device must be in High impedance state to avoid high currents that would exceed the maximum ratings when the outputs of the 3-State devices are tied together. When the output of more than one device is tied together the user must ensure that there is no overlap in the active Low portion of the output enable voltages. PIN CONFIGURATION I3 I2 I1 I0 Y Y OE GND 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 VCC I4 I5 I6 I7 S0 S1 S2 SF00778 TYPE 74F251A TYPICAL PROPAGATION DELAY 4.5ns TYPICAL SUPPLY CURRENT (TOTAL) 19mA ORDERING INFORMATION ORDER CODE DESCRIPTION COMMERCIAL RANGE VCC = 5V 10%, Tamb = 0C to +70C N74F251AN N74F251AD PKG DWG # SOT38-4 SOT162-1 16-pin plastic DIP 16-pin plastic SO INPUT AND OUTPUT LOADING AND FAN-OUT TABLE PINS I0-I7 S0-S2 OE Y, Y Data inputs Select inputs Output Enable input (active Low) Data outputs DESCRIPTION 74F (U.L.) HIGH/LOW 1.0/1.0 1.0/1.0 1.0/1.0 150/40 LOAD VALUE HIGH/LOW 20A/0.6mA 20A/0.6mA 20A/0.6mA 3mA/24mA NOTE: One (1.0) FAST unit load is defined as: 20A in the High state and 0.6mA in the Low state. LOGIC SYMBOL 4 3 2 1 15 14 13 12 IEC/IEEE SYMBOL 7 11 10 I0 I1 I2 I3 I4 I5 I6 I7 9 4 3 2 1 6 0 G 2 0 7 5 MUX EN 11 10 9 7 S0 S1 S2 OE Y Y 15 14 13 VCC = Pin 16 GND = Pin 8 5 6 12 SF00779 SF00780 1996 Jan 05 1 853-0358 16191 Philips Semiconductors Product specification 8-input multiplexer (3-State) 74F251A LOGIC DIAGRAM I0 4 S0 11 I1 3 I2 2 I3 1 I4 15 I5 14 I6 13 I7 12 S1 10 S2 9 7 OE 5 VCC = Pin 16 GND = Pin 8 Y Y 6 SF00781 FUNCTION TABLE INPUTS S2 X L L L L H H H H S1 X L L H H L L H H S0 X L H L H L H L H OE H L L L L L L L L OUTPUTS Y Z I0 I1 I2 I3 I4 I5 I6 I7 Y Z I0 I1 I2 I3 I4 I5 I6 I7 NOTES: H = High voltage level L = Low voltage level X = Don't care Z = High impedance "off" state 1996 Jan 05 2 Philips Semiconductors Product specification 8-input multiplexer (3-State) 74F251A ABSOLUTE MAXIMUM RATINGS (Operation beyond the limit set forth in this table may impair the useful life of the device. Unless otherwise noted these limits are over the operating free air temperature range.) SYMBOL VCC VIN IIN VOUT IOUT Tamb Tstg Supply voltage Input voltage Input current Voltage applied to output in High output state Current applied to output in Low output state Operating free-air temperature range Storage temperature PARAMETER RATING -0.5 to +7.0 -0.5 to +7.0 -30 to +5 -0.5 to VCC 48 0 to +70 -65 to +150 UNIT V V mA V mA C C RECOMMENDED OPERATING CONDITIONS SYMBOL VCC VIH VIL IIK IOH IOL Tamb Supply voltage High-level input voltage Low-level input voltage Input clamp current High-level output current Low-level output current Operating free-air temperature range 0 PARAMETER LIMITS MIN 4.5 2.0 0.8 -18 -3 24 70 NOM 5.0 MAX 5.5 UNIT V V V mA mA mA C DC ELECTRICAL CHARACTERISTICS (Over recommended operating free-air temperature range unless otherwise noted.) SYMBOL PARAMETER TEST CONDITIONS1 VCC = MIN, VIL = MAX, VIH = MIN, IOH = MAX VCC = MIN, VIL = MAX, VIH = MIN, IOL = MAX VCC = MIN, II = IIK VCC = MAX, VI = 7.0V VCC = MAX, VI = 2.7V VCC = MAX, VI = 0.5V VCC = MAX, VI = 2.7V VCC = MAX, VI = 0.5V VCC = MAX VCC = MAX -60 20 17 21 LIMITS MIN TYP2 MAX UNIT V 3.3 0.35 0.35 -0.73 0.50 0.50 -1.2 100 20 -0.6 50 -50 -150 27 24 29 V V V V A A mA A mA mA mA mA mA VOH High-level output voltage 10%VCC 5%VCC 10%VCC 5%VCC 2.4 2.7 VOL VIK II IIH IIL IOZH IOZL IOS ICC Low-level output voltage Input clamp voltage Input current at maximum input voltage High-level input current Low-level input current Off-state output current High-level voltage applied Off-state output current Low-level voltage applied Short-circuit output current3 ICCH Supply (total) S pply current ( l) ) ICCL ICCZ NOTES: 1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions for the applicable type. 2. All typical values are at VCC = 5V, Tamb = 25C. 3. Not more than one output should be shorted at a time. For testing IOS, the use of high-speed test apparatus and/or sample-and-hold techniques are preferable in order to minimize internal heating and more accurately reflect operational values. Otherwise, prolonged shorting of a High output may raise the chip temperature well above normal and thereby cause invalid readings in other parameter tests. In any sequence of parameter tests, IOS tests should be performed last. 1996 Jan 05 3 Philips Semiconductors Product specification 8-input multiplexer (3-State) 74F251A AC ELECTRICAL CHARACTERISTICS LIMITS TEST CONDITION MIN tPLH tPHL tPLH tPHL tPLH tPHL tPLH tPHL tPZH tPZL tPHZ tPLZ tPZH tPZL tPHZ tPLZ Propagation delay In to Y Propagation delay In to Y Propagation delay Sn to Y Propagation delay Sn to Y Output Enable time OE to Y Output Disable time OE to Y Output Enable time OE to Y Output Disable time OE to Y Waveform 2 Waveform 1 Waveform 1 Waveform 2 Waveform 1 Waveform 2 Waveform 3 Waveform 4 Waveform 3 Waveform 4 Waveform 3 Waveform 4 Waveform 3 Waveform 4 3.0 3.0 2.5 1.0 4.5 4.0 3.5 2.5 3.5 3.5 2.5 1.0 2.5 2.5 3.5 1.0 VCC = +5V Tamb = +25C CL = 50pF RL = 500 TYP 5.0 5.0 4.5 2.5 6.5 5.5 6.0 4.5 5.5 5.0 4.0 4.0 4.0 4.0 5.0 2.0 MAX 7.0 7.0 7.0 5.0 10.0 9.0 9.0 7.0 7.5 7.5 6.5 6.0 6.5 6.5 7.5 4.5 VCC = +5V 10% Tamb = 0C to +70C CL = 50pF RL = 500 MIN 2.5 3.0 2.0 1.0 4.0 3.5 3.5 2.5 3.0 3.0 2.0 1.0 2.0 2.5 3.0 1.0 MAX 8.0 8.0 7.5 5.0 11.5 9.5 9.5 7.5 8.5 8.0 7.0 6.5 7.0 7.0 8.0 4.5 ns ns ns ns ns ns ns ns SYMBOL PARAMETER UNIT AC WAVEFORMS For all waveforms, VM = 1.5V VIN VIN VM tPHL VM tPLH VM tPLH VM tPHL VOUT VM VM VOUT VM VM SF00782 SF00092 Waveform 1. For Inverting Outputs Waveform 2. For Non-Inverting Outputs OE VM tPZH VM tPHZ VOH -0.3V OE VM tPZL VM tPLZ VM VOL +0.3V Y, Y VM 0V Y, Y SF00784 SF00785 Waveform 3. 3-State Output Enable Time to High Level and Output Disable Time from High Level Waveform 4. 3-State Output Enable Time to Low Level and Output Disable Time from Low Level 1996 Jan 05 4 Philips Semiconductors Product specification 8-input multiplexer (3-State) 74F251A TEST CIRCUIT AND WAVEFORMS VCC 7.0V VIN PULSE GENERATOR RT D.U.T. VOUT RL NEGATIVE PULSE 90% VM 10% tTHL (tf ) CL RL tTLH (tr ) 90% POSITIVE PULSE 10% tTHL (tf ) AMP (V) 90% VM tw 10% 0V tw VM 10% tTLH (tr ) 0V AMP (V) 90% Test Circuit for 3-State Outputs SWITCH POSITION TEST tPLZ tPZL All other SWITCH closed closed open VM Input Pulse Definition DEFINITIONS: RL = Load resistor; see AC electrical characteristics for value. CL = Load capacitance includes jig and probe capacitance; see AC electrical characteristics for value. RT = Termination resistance should be equal to ZOUT of pulse generators. INPUT PULSE REQUIREMENTS family amplitude VM 74F 3.0V 1.5V rep. rate 1MHz tw 500ns tTLH 2.5ns tTHL 2.5ns SF00777 1996 Jan 05 5 |
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