HD74HCT138
HD74HCT138 is 3-to-8-line Decoder/Demultiplexer manufactured by Hitachi Semiconductor.
Description
The HD74HCT138 has 3 binary select inputs (A, B, and C). If the device is enabled these inputs determine which one of the eight normally high outputs will go low. Two active low and one active high enables (G1, G2A and G2B) are provided to ease the cascading of decoders.
Features
- -
- -
- - LSTTL Output Logic Level patibility as well as CMOS Output patibility High Speed Operation: tpd (A, B, C to Y) = 18.5 ns typ (CL = 50 p F) High Output Current: Fanout of 10 LSTTL Loads Wide Operating Voltage: VCC = 4.5 to 5.5 V Low Input Current: 1 µA max Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C)
Function Table
Inputs Enable G1 X X L H H H H H H H H G2A X H X L L L L L L L L G2B H X X L L L L L L L L Select C X X X L L L L H H H H B X X X L L H H L L H H A X X X L H L H L H L H Outputs 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
Pin Arrangement
A Select Inputs B C G2A Enable Inputs G2B G1 Outputs Y7 GND
1 2 3 4 5 6 7 8 (Top view) B C G2A G2B G1 Y7 A Y0 Y1 Y2 Y3 Y4 Y5
16 VCC 15 Y0 14 Y1 13 Y2 12 Y3 11 Y4 10 Y5 9 Y6 Outputs
Y6
DC Characteristics
Ta = 25°C Item Input voltage Symbol VIH VIL Output voltage VOH Ta =
- 40 to +85°C Max
- 0.8
- - 0.1 0.33 ±1.0 40 µA µA V Unit V V V Test Conditions VCC (V) 4.5 to 5.5 4.5 to 5.5 4.5 4.5 4.5 4.5 5.5 5.5 Vin = VIH or VIL I OH =
- 20 µA I OH =
- 4 m A Vin = VIH or VIL I OL = 20 µA I OL = 4 m A Vin = VCC or GND Vin = VCC or GND, Iout = 0 µA
Min Typ Max Min 2.0
- 4.4
- -
- - 2.0
- -
- 4.4 4.13
- VOL
- - Input current Quiescent supply current Iin I CC
- -
- -
- -
- 0.26
- ±0.1
- 4.0
- AC Characteristics (CL = 50 p F, Input tr = tf = 6 ns)
Ta = 25°C Item Symbol Ta =
- 40 to +85°C Max 44 38 38 38 44 38 19 10 Unit ns ns ns ns ns ns ns p F Test Conditions VCC (V) 4.5 4.5 4.5 4.5 4.5 4.5...