Features
• Multifunction Capability
- Binary to 1 of 4 Decoders or 1 to 4 Line
Demultiplexer
• Active Low Mutually Exclusive Outputs
• Fanout (Over Temperature Range)
- Standard Outputs . . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
• Wide Operating Temperature Range . . . -55oC to 125oC
• Balanced Propagation Delay and Transition Times
• Significant Power Reduction Compared to LSTTL
Logic ICs
• HC Types
- 2V to 6V Operation
- High Noise Immunity: NIL = 30%, NIH = 30%of VCC at
VCC = 5V
• HCT Types
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility,
VIL= 0.8V (Max), VIH = 2V (Min)
- CMOS Input Compatibility, Il ≤ 1μA at VOL, VOH
• Memory Decoding, Data Routing, Code Conversion

Description
The ’HC139 and ’HCT139 devices contain two independent
binary to one of four decoders each with a single active low
enable input (1E or 2E). Data on the select inputs (1A0 and
1A1 or 2A0 and 2A1) cause one of the four normally high
outputs to go low.
If the enable input is high all four outputs remain high. For
demultiplexer operation the enable input is the data input.
The enable input also functions as a chip select when these
devices are cascaded. This device is functionally the same
as the CD4556B and is pin compatible with it.
The outputs of these devices can drive 10 low power
Schottky TTL equivalent loads. The HCT logic family is
functionally as well as pin equivalent to the LS logic family.