CD74AC238

Features:

• CD74AC138, CD74ACT138 . . . . . . . . . . . . . . . Inverting
• CD74AC238, CD74ACT238 . . . . . . . . . . . Non-Inverting
• Buffered Inputs
• Typical Propagation Delay
  - 5ns at V_CC = 5V, T_A = 25, C_L = 50pF
• Exceeds 2kV ESD Protection MIL-STD-883, Method 3015
• SCR-Latchup-Resistant CMOS Process and Circuit Design
• Speed of Bipolar FAST™/AS/S with Significantly Reduced Power Consumption
• Balanced Propagation Delays
• AC Types Feature 1.5V to 5.5V Operation and Balanced Noise Immunity at 30% of the Supply
• ±24mA Output Drive Current
  - Fanout to 15 FAST™ ICs
  - Drives 50W Transmission Lines


Application

The CD74AC138, CD74ACT138, CD74AC238, and CD74ACT238 are 3-to-8-line decoders/demultiplexers that utilize the Harris Advanced CMOS Logic technology. Both circuits have three binary select inputs (A0, A1, and A2). If the device is enabled, these inputs determine which one of the eight normally HIGH outputs of the AC/ACT138 will go LOW or which on of the normally LOW outputs of the AC/ACT238 will go HIGH. Two active LOW and one active HIGH enables (E1, E2 and E3) are provided to simplify the cascading of these devices.


Pinout




Specifications

DC Supply Voltage, V_CC . . . . . . . . . . . . . . . . . . . . . . .  . -0.5V to 6V
DC Input Diode Current, I_IK
For V_I < -0.5V or V_I > V_CC + 0.5V . . . . . . . . . . . . . . .  . . . . .±20mA
DC Output Diode Current, I_OK
For V_O < -0.5V or V_O > V_CC + 0.5V . . . . . . . . . . . . . . . . . .. .±50mA
DC Output Source or Sink Current per Output Pin, I_O
For V_O > -0.5V or V_O < V_CC + 0.5V . . . . . . . . . . . . . . . .  .  . .±50mA
DC V_CC or Ground Current, I_CC or I_GND (Note 5) . . . . . .  . .±100mA 


Description

The CD74AC138, CD74ACT138, CD74AC238, and CD74ACT238 are 3-to-8-line decoders/demultiplexers that utilize the Harris Advanced CMOS Logic technology. Both circuits have three binary select inputs (A0, A1, and A2). If CD74AC238 is enabled, these inputs determine which one of the eight normally HIGH outputs of the AC/ACT138 will go LOW or which on of the normally LOW outputs of the AC/ACT238 will go HIGH. Two active LOW and one active HIGH enables (E1, E2 and E3) are provided to simplify the cascading of these devices.