HD74HC42
HD74HC42 is BCD-to-Decimal Decoder manufactured by Hitachi Semiconductor.
Description
Data on the four input pins select one of the 10 outputs corresponding to the value of the BCD number on the inputs. An output will go low when selected, otherwise it remains high. If the input data is not a valid BCD number all outputs will remain high.
Features
- -
- -
- High Speed Operation: tpd = 13 ns typ (CL = 50 p F) High Output Current: Fanout of 10 LSTTL Loads Wide Operating Voltage: VCC = 2 to 6 V Low Input Current: 1 µA max Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C)
Function Table
BCD Inputs No. 0 1 2 3 4 5 6 7 8 9 D L L L L L L L L H H C L L L L H H H H L L L L H H H H B L L H H L L H H L L H H L L H H A L H L H L H L H L H L H L H L H Decimal Outputs 0 L H H H H H H H H H H H H H H H 1 H L H H H H H H H H H H H H H H 2 H H L H H H H H H H H H H H H H 3 H H H L H H H H H H H H H H H H 4 H H H H L H H H H H H H H H H H 5 H H H H H L H H H H H H H H H H 6 H H H H H H L H H H H H H H H H 7 H H H H H H H L H H H H H H H H 8 H H H H H H H H L H H H H H H H 9 H H H H H H H H H L H H H H H H
INVALID H H H H H H
Pin Arrangement
0Y 1 0 1Y 2 2Y 3 Outputs 3Y 4 4Y 5 5Y 6 6Y 7 GND 8 (Top view) 1 2 3 4 5 6 7 8 9 D C B A
16 VCC 15 A 14 B 13 C 12 D 11 9Y 10 8Y 9 7Y Outputs
Inputs
Logic Diagram
0Y 1Y A 2Y 3Y B 4Y 5Y C 6Y 7Y D 8Y 9Y
DC Characteristics
Ta = 25°C Item Input voltage Symbol VIH Ta =
- 40 to +85°C Max
- -
- 0.5 1.35 1.8
- -
- -
- 0.1 0.1 0.1 0.33 0.33 ±1.0 40 µA µA I OL = 4 m A I OL = 5.2 m A Vin = VCC or GND Vin = VCC or GND, Iout = 0 µA V I OH =
- 4 m A I OH =
- 5.2 m A Vin = VIH or VIL I OL = 20 µA V Vin = VIH or VIL I OH =
- 20 µA V Unit V Test Conditions
VCC (V) Min Typ Max Min 2.0 4.5 6.0 1.5
- 3.15
- 4.2
- -
- -
- -
- -
- - 0.5 1.5 3.15 4.2
- VIL
2.0 4.5 6.0
- 1.8
- 1.9 4.4 5.9 4.13...