74VHCT138A 3 TO 8 LINE DECODER (INVERTING) PRELIMINARY DATA ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ HIGH SPEED: tPD = 7.6 ns (TYP.) at VCC = 5V LOW POWER DISSIPATION: ICC = 4 µA (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 138 IMPROVED LATCH-UP IMMUNITY LOW NOISE: VOLP = 0.8V (Max.) DESCRIPTION The 74VHCT138A is an advanced high-speed CMOS 3 TO 8 LINE DECODER (INVERTING) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS technology. If the device is enabled, 3 binary select inputs (A, B and C) determine which one of the outputs will go low. If enable input G1 is held low or either SOP TSSOP ORDER CODES PACKAGE T UBE T& R SOP 74VHCT138AM 74VHCT138AMTR TSSOP 74VHCT138ATTR G2A or G2B is held high, the decoding function is inhibited and all the 8 outputs go to high. Three enable inputs are provided to ease cascade connection and application of address decoders for memory systems. Power down protection is provided on all inputs and outputs 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. PIN CONNECTION AND IEC LOGIC SYMBOLS March 2000 1/8 74VHCT138A INPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL 1, 2, 3 A, B, C NAME AND FUNCT ION 4, 5 G2A, G2B Enable Inputs 6 G1 Enable Input 15, 14, 13, 12, 11, 10, 9, 7 Y0 to Y7 8 GND Ground (0V) 16 VCC Positive Supply Voltage Address Inputs Outputs TRUTH TABLE INPUT S ENABL E G2B G2A G1 C X X L X X H X X H X X X L L H L L L H L L L H L L L H L L L H H L L H H L L H H L L H H OUTPUTS SELECT B X X X L L H H L L H H A X X X L H L H L H L H X:Don’t Care LOGIC DIAGRAM Thislogic diagram has notbe used to estimate propagation delays 2/8 Y0 H H H L H H H H H H H Y1 H H H H L H H H H H H Y2 H H H H H L H H H H H Y3 H H H H H H L H H H H Y4 H H H H H H H L H H H Y5 H H H H H H H H L H H Y6 H H H H H H H H H L H Y7 H H H H H H H H H H L 74VHCT138A ABSOLUTE MAXIMUM RATINGS Symbol VCC Parameter Supply Voltage Value Unit -0.5 to +7.0 V VI DC Input Voltage -0.5 to +7.0 V VO DC Output Voltage (see note 1) -0.5 to +7.0 V VO DC Output Voltage (see note 2) -0.5 to VCC + 0.5 V IIK DC Input Diode Current - 20 mA IOK DC Output Diode Current ± 20 mA IO DC Output Current ± 25 mA ± 50 mA ICC or IGND DC VCC or Ground Current Tstg TL Storage Temperature -65 to +150 o 300 o Lead Temperature (10 sec) 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) VCC=0 2) High or Low State RECOMMENDED OPERATING CONDITIONS Symbol VCC Parameter Supply Voltage Valu e Unit 4.5 to 5.5 V VI Input Voltage 0 to 5.5 V VO Output Voltage (see note 1) 0 to 5.5 V VO Output Voltage (see note 2) Top Operating Temperature dt/dv 0 to VCC V o -40 to +85 Input Rise and Fall Time (see note 3) (V CC = 5.0 ± 0.5V) C 0 to 20 ns/V 1) VCC=0 2) High or Low State 3)VIN from0.8V to 2 V DC SPECIFICATIONS Symb ol Parameter T est Cond ition s Min. 2 VIH High Level Input Voltage 4.5 to 5.5 VIL Low Level Input Voltage 4.5 to 5.5 VOH High Level Output Voltage VOL Low Level Output Voltage Value T A = 25 o C V CC (V) Typ . Un it -40 to 85 o C Max. Min . 0.8 4.5 I O =-50 µA 4.4 4.5 IO=-8 mA 3.94 4.5 I O=50 µA 4.5 Max. 2 4.5 V 0.8 4.4 V 3.8 0.0 V 0.1 0.1 IO=8 mA 0.36 0.44 V 0 to 5.5 VI = 5.5V or GND ±0.1 ±1.0 µA ICC Quiescent Supply Current 5.5 VI = VCC or GND 4 40 µA ∆ICC Additional Worst Case Supply Current 5.5 One Input at 3.4V, other input at VCC or GND 1.35 1.5 mA IOPD Output Leakage Current 0 VOUT = 5.5V 0.5 5.0 µA II Input Leakage Current 3/8 74VHCT138A AC ELECTRICAL CHARACTERISTICS (Input t r = tf =3 ns) Symb ol Parameter tPLH tPHL Propagation Delay Time A, B, C to Y 5.0(*) 15 Value T A = 25 o C Min. Typ . Max. 7.6 10.4 5.0(*) 50 8.1 11.4 1.0 13.0 tPLH tPHL Propagation Delay Time G1 to Y 5.0(*) 5.0(*) 15 50 6.6 7.1 9.1 10.1 1.0 1.0 10.5 11.5 ns tPLH tPHL Propagation Delay Time G2A, G2B to Y 5.0(*) 5.0(*) 15 50 7.0 7.5 9.6 10.6 1.0 1.0 11.0 12.0 ns V CC (V) Test Co ndition CL (pF ) Un it -40 to 85 o C Min . Max. 1.0 12.0 ns (*) Voltage range is 5V ± 0.5V CAPACITIVE CHARACTERISTICS Symb ol Parameter T est Cond ition s Value o T A = 25 C Min. Typ . Max. C IN Input Capacitance 4 CPD Power Dissipation Capacitance (note 1) 49 10 Un it o -40 to 85 C Min . Max. 10 pF pF 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 TEST CIRCUIT CL = 15/50 pF or equivalent (includes jig and probe capacitance) RT = ZOUT of pulse generator (typically 50Ω) 4/8 74VHCT138A WAVEFORM 1: PROPAGATION DELAYS FOR INVERTING OUTPUTS (f=1MHz; 50% duty cycle) WAVEFORM 2: PROPAGATION DELAYS FOR NON-INVERTING OUTPUTS (f=1MHz; 50% duty cycle) 5/8 74VHCT138A SO-16 MECHANICAL DATA mm DIM. MIN. TYP. A a1 inch MAX. MIN. TYP. 1.75 0.1 0.068 0.2 a2 MAX. 0.004 0.007 1.65 0.064 b 0.35 0.46 0.013 0.018 b1 0.19 0.25 0.007 0.010 C 0.5 0.019 c1 45 (typ.) D 9.8 10 0.385 0.393 E 5.8 6.2 0.228 0.244 e 1.27 0.050 e3 8.89 0.350 F 3.8 4.0 0.149 0.157 G 4.6 5.3 0.181 0.208 L 0.5 1.27 0.019 0.050 M S 0.62 0.024 8 (max.) P013H 6/8 74VHCT138A TSSOP16 MECHANICAL DATA mm DIM. MIN. inch TYP. A MAX. MIN. TYP. MAX. 1.1 0.433 A1 0.05 0.10 0.15 0.002 0.004 0.006 A2 0.85 0.9 0.95 0.335 0.354 0.374 b 0.19 0.30 0.0075 0.0118 c 0.09 0.20 0.0035 0.0079 D 4.9 5 5.1 0.193 0.197 0.201 E 6.25 6.4 6.5 0.246 0.252 0.256 E1 4.3 4.4 4.48 0.169 0.173 0.176 e 0.65 BSC 0.0256 BSC K 0o 4o 8o 0o 4o 8o L 0.50 0.60 0.70 0.020 0.024 0.028 A A2 A1 b e K c L E D E1 PIN 1 IDENTIFICATION 1 7/8 74VHCT138A Information furnished is believed to be accurate and reliable. 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