The 74HC138; 74HCT138 decodes three binary weighted address inputs (A0, A1 and A2) to eight mutually exclusive outputs (Y0 to Y7). The device features three enable inputs (E1, E2 and E3). Every output will be HIGH unless E1 and E2 are LOW and E3 is HIGH. This multiple enable function allows easy parallel expansion to a 1-of-32 (5 to 32 lines) decoder with just four '138 ICs and one inverter. The '138 can be used as an eight output demultiplexer by using one of the active LOW enable inputs as the data input and the remaining enable inputs as strobes. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.
Features and benefits
Wide supply voltage range from 2.0 to 6.0 V
CMOS low power dissipation
High noise immunity
Latch-up performance exceeds 100 mA per JESD 78 Class II Level B
Demultiplexing capability
Multiple input enable for easy expansion
Ideal for memory chip select decoding
Active LOW mutually exclusive outputs
Input levels:
For 74HC138: CMOS level
For 74HCT138: TTL level
Complies with JEDEC standards:
JESD8C (2.7 V to 3.6 V)
JESD7A (2.0 V to 6.0 V)
ESD protection:
HBM: ANSI/ESDA/JEDEC JS-001 class 2 exceeds 2000 V
CDM: ANSI/ESDA/JEDEC JS-002 class C3 exceeds 1000 V
Multiple package options
Specified from -40 °C to +85 °C and from -40 °C to +125 °C
The 74HC138; 74HCT138 decodes three binary weighted address inputs (A0, A1 and A2) to eight mutually exclusive outputs (Y0 to Y7). The device features three enable inputs (E1, E2 and E3). Every output will be HIGH unless E1 and E2 are LOW and E3 is HIGH. This multiple enable function allows easy parallel expansion to a 1-of-32 (5 to 32 lines) decoder with just four '138 ICs and one inverter. The '138 can be used as an eight output demultiplexer by using one of the active LOW enable inputs as the data input and the remaining enable inputs as strobes. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.
Features and benefits
- Wide supply voltage range from 2.0 to 6.0 V
- CMOS low power dissipation
- High noise immunity
- Latch-up performance exceeds 100 mA per JESD 78 Class II Level B
- Demultiplexing capability
- Multiple input enable for easy expansion
- Ideal for memory chip select decoding
- Active LOW mutually exclusive outputs
- Input levels:
- For 74HC138: CMOS level
- For 74HCT138: TTL level
- Complies with JEDEC standards:
- JESD8C (2.7 V to 3.6 V)
- JESD7A (2.0 V to 6.0 V)
- ESD protection:
- HBM: ANSI/ESDA/JEDEC JS-001 class 2 exceeds 2000 V
- CDM: ANSI/ESDA/JEDEC JS-002 class C3 exceeds 1000 V
- Multiple package options
- Specified from -40 °C to +85 °C and from -40 °C to +125 °C
