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(R)
74VHCT257A
QUAD 2 CHANNEL MULTIPLEXER (3-STATE)
PRELIMINARY DATA
s s
s
s
s
s
s
s
s s
HIGH SPEED: tPD = 5.8 ns (TYP.) at VCC = 5V LOWPOWER DISSIPATION: ICC = 4 A (MAX.) at TA = 25 oC COMPATIBLE WITH TTL OUTPUTS: VIH = 2V (MIN), VIL = 0.8V (MAX) POWER DOWN PROTECTION ON INPUTS & OUTPUTS SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 8 mA (MIN) BALANCED PROPAGATION DELAYS: tPLH tPHL OPERATING VOLTAGE RANGE: VCC (OPR) = 4.5V to 5.5V PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 257 IMPROVED LATCH-UP IMMUNITY LOWNOISE: VOLP = 0.8V (Max.)
SOP
PACKAGE SOP TSSOP T UBE 74VHCT257AM
TSSOP
T&R 74VHCT257AMTR 74VHCT257ATTR
ORDER CODES
DESCRIPTION The 74VHCT257A is an advanced high-speed CMOS QUAD 2 CHANNEL MULTIPLEXER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS technology. It is composed of four independent 2 channel multiplexers with common SELECT and ENABLE INPUT. PIN CONNECTION AND IEC LOGIC SYMBOLS
The 74VHCT257A is a non inverting multiplexer. When the ENABLE INPUT is held "High", all outputs become high impedance state. If SELECT INPUT is held "Low", "A" data is selected, when SELECT INPUT is "High", "B" data is chosen. Power down protection is provided on all inputs and output and 0 to 7V can be accepted on inputs with no regard to the supply voltage. This device can be used to interface 5V to 3V. All inputs and outputs are equipped with protection circuits against static discharge, giving them 2KV ESD immunity and transient excess voltage.
March 2000
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74VHCT257A
INPUT EQUIVALENT CIRCUIT PIN DESCRIPTION
PIN No 1 2, 5, 14, 11 3, 6, 13, 10 4, 7, 12, 9 15 8 16 SYMBOL SELECT 1A to 4A 1B to 4B 1Y to 4Y OE GND VCC NAME AND FUNCT ION Common Data Select Input Data Inputs from Source A Data Inputs from Source B 3 State Multiplexer Outputs 3 State Output Enable Input (Active LOW) Ground (0V) Positive Supply Voltage
TRUTH TABLE
INPUT S OE H L L L L
X = DON'T CARE Z = HIGH IMPEDANCE
OUTPUTS A X L H X X B X X X L H Y Z L H L H
SELE CT X L L H H
LOGIC DIAGRAM
Thislogic diagram has notbe used to estimate propagation delays
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74VHCT257A
ABSOLUTE MAXIMUM RATINGS
Symbol VCC VI VO VO IIK IOK IO Tstg TL Supply Voltage DC Input Voltage DC Output Voltage (see note 1) DC Output Voltage (see note 2) DC Input Diode Current DC Output Diode Current DC Output Current Storage Temperature Lead Temperature (10 sec) Parameter Value -0.5 to +7.0 -0.5 to +7.0 -0.5 to +7.0 -0.5 to VCC + 0.5 - 20 20 25 50 -65 to +150 300 Unit V V V V mA mA mA mA
o o
ICC or IGND DC VCC or Ground Current
C C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. 1) Output in OFF State 2) High or Low State
RECOMMENDED OPERATING CONDITIONS
Symbol VCC VI VO VO Top dt/dv Supply Voltage Input Voltage Output Voltage (see note 1) Output Voltage (see note 2) Operating Temperature Input Rise and Fall Time (see note 3) (V CC = 5.0 0.5V) Parameter Valu e 4.5 to 5.5 0 to 5.5 0 to 5.5 0 to VCC -40 to +85 0 to 20 Unit V V V V
o
C
ns/V
1) Output in OFF State 2) High or Low State 3)VIN from0.8V to 2 V
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74VHCT257A
DC SPECIFICATIONS
Symb ol Parameter T est Cond ition s V CC (V) VIH VIL VOH VOL IOZ High Level Input Voltage Low Level Input Voltage High Level Output Voltage Low Level Output Voltage High Impedance Output Leakage Current Input Leakage Current Quiescent Supply Current Additional Worst Case Supply Current Output Leakage Current 4.5 to 5.5 4.5 to 5.5 4.5 4.5 4.5 4.5 4.5 to 5.5 I O =-50 A IO=-8 mA I O=50 A IO=8 mA VI = VIH or VIL VO = 0V to 5.5V VI = 5.5V or GND VI = VCC or GND One Input at 3.4V, other input at VCC or GND VOUT = 5.5V 4.4 3.94 0.0 0.1 0.36 0.25 4.5 Min. 2 0.8 4.4 3.8 0.1 0.44 2.5 Typ . Value T A = 25 o C Max. -40 to 85 o C Min . 2 0.8 Max. V V Un it
V V A
II ICC ICC
0 to 5.5 5.5 5.5
0.1 4 1.35
1.0 40 1.5
A A mA
IOPD
0
0.5
5.0
A
AC ELECTRICAL CHARACTERISTICS (Input t r = tf =3 ns)
Symb ol Parameter V CC (V) tPLH tPHL tPLH tPHL tPZL tPZH tPLZ tPHZ Propagation Delay Time A, B to Y Propagation Delay Time SELECT to Y Output Enable Time Output Disable Time Test Co ndition CL (pF ) 15 50 15 50 15 50 50 Value T A = 25 o C Min. Typ . Max. 5.8 8.3 7.0 9.5 6.7 9.2 8.6 9.3 12.8 11.0 14.5 10.5 14.0 12.0 Un it -40 to 85 o C Min . Max. 1.0 1.0 1.0 1.0 1.0 1.0 1.0 11.0 14.5 13.0 16.5 12.5 16.0 13.5 ns ns ns ns
5.0 5.0(*) 5.0(*) 5.0(*) 5.0(*) 5.0(*) 5.0(*)
(*)
(*) Voltage range is 5V 0.5V
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74VHCT257A
CAPACITIVE CHARACTERISTICS
Symb ol Parameter T est Cond ition s Min. C IN COUT CPD Input Capacitance Output Capacitance Power Dissipation Capacitance (note 1) Typ . 4 6 23 Value T A = 25 o C Max. 10 -40 to 85 o C Min . Max. 10 pF pF pF Un it
1) CPD isdefined as the value of the IC'sinternal equivalent capacitance which is calculated fromthe operating current consumption without load. (Referto Test Circuit).Average operating current can be obtained by the following equation. ICC(opr) = CPD * VCC * fIN + ICC/4 (per Channel)
DYNAMIC SWITCHING CHARACTERISTICS
Symb ol Parameter T est Cond ition s V CC (V) VOLP VOLV VIHD VILD Dynamic Low Voltage Quiet Output (note 1, 2) Dynamic High Voltage Input (note 1, 3) Dynamic Low Voltage Input (note 1, 3) 5.0 -0.8 5.0 5.0 C L = 50 pF 2.0 0.8
o
Value T A = 25 C Min. Typ . 0.3 -0.3 Max. 0.8 -40 to 85 C Min . Max.
o
Un it
V
1) Worst case package. 2) Max number of outputs defined as (n). Data inputs are driven 0V to 3.0V, (n -1) outputs switching and one output at GND. 3) Max number of data inputs (n) switching. (n-1) switching 0V to3.0V. Inputs under test switching: 3.0V to threshold (VILD), 0V to threshold (VIHD), f=1MHz.
TEST CIRCUIT
T EST tPLH , tPHL tPZL , tPLZ tPZH , tPHZ
CL = 15/50 pF or equivalent (includes jig and probe capacitance) RL = R1 = 1K orequivalent RT = ZOUT of pulse generator (typically 50)
SW IT CH Open VCC GND
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74VHCT257A
WAVEFORM 1: PROPAGATION DELAYS FOR INVERTING CONDITIONS (f=1MHz; 50% duty cycle)
WAVEFORM 2: PROPAGATION DELAYS FOR NON-INVERTING CONDITIONS (f=1MHz; 50% duty cycle)
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WAVEFORM 3: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle)
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74VHCT257A
SO-16 MECHANICAL DATA
DIM. MIN. A a1 a2 b b1 C c1 D E e e3 F G L M S 3.8 4.6 0.5 9.8 5.8 1.27 8.89 4.0 5.3 1.27 0.62 8 (max.) 0.149 0.181 0.019 10 6.2 0.35 0.19 0.5 45 (typ.) 0.385 0.228 0.050 0.350 0.157 0.208 0.050 0.024 0.393 0.244 0.1 mm TYP. MAX. 1.75 0.2 1.65 0.46 0.25 0.013 0.007 0.019 0.004 MIN. inch TYP. MAX. 0.068 0.007 0.064 0.018 0.010
P013H
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74VHCT257A
TSSOP16 MECHANICAL DATA
mm MIN. A A1 A2 b c D E E1 e K L 0o 0.50 0.05 0.85 0.19 0.09 4.9 6.25 4.3 5 6.4 4.4 0.65 BSC 4o 0.60 8o 0.70 0o 0.020 0.10 0.9 TYP. MAX. 1.1 0.15 0.95 0.30 0.20 5.1 6.5 4.48 0.002 0.335 0.0075 0.0035 0.193 0.246 0.169 0.197 0.252 0.173 0.0256 BSC 4o 0.024 8o 0.028 0.004 0.354 MIN. inch TYP. MAX. 0.433 0.006 0.374 0.0118 0.0079 0.201 0.256 0.176
DIM.
A
A2 A1 b e K c L E
D
E1
PIN 1 IDENTIFICATION
1
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74VHCT257A
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