Part A
74HC139D
Toshiba Semiconductor và lưu trữ
- Lifecycle
- Active
- Stock
- 4290 PCS
- Package
- SOIC-16
- Series
- Logic - Signal Switches, Multiplexers, Decoders
Replacement verdict
Not a drop-in replacement
The 74HC153D and 74HC139D are not functionally interchangeable despite sharing the same 74HC logic family and SOIC-16 package. The 74HC153D is a dual 4-to-1 multiplexer, while the 74HC139D is a dual 2-to-4 decoder/demultiplexer. Their internal signal routing, input-to-output mapping, and control logic differ fundamentally, so neither device can directly substitute for the other in an existing design without circuit redesign.
Different logic function
Different input-to-output mapping
Different control logic
Different signal routing
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC153D | 74HC139D | Why it matters |
|---|---|---|---|
| Logic Function | Dual 4-input multiplexer | Dual 2-to-4 line decoder/demultiplexer | Defines the core function; these devices are not functionally interchangeable as they perform selection versus decoding operations. |
| Number of Select/Address Inputs | 2 (shared per multiplexer) | 2 (per decoder) | Determines how many input lines can be selected or decoded, affecting system addressing capability. |
| Number of Data Inputs | 8 (4 per multiplexer) | 2 (1 per decoder) | Affects how many signal sources can be routed or decoded by the device. |
| Number of Outputs | 2 (1 per multiplexer) | 4 (2 per decoder) | Determines how many destinations or decoded lines the device can drive. |
| Output Type | Non-inverting (Y = selected input) | Inverting (active LOW outputs) | Polarity affects compatibility with downstream logic and whether external inverters are needed. |
| Enable/Strobe Inputs | 2 (active LOW, one per multiplexer) | 2 (active LOW, one per decoder) | Enables cascading and output tri-stating or disabling for bus sharing and power management. |
| Supply Voltage Range | 2.0 V to 6.0 V | 2.0 V to 6.0 V | Defines compatible logic families and system power rails for direct replacement. |
| Propagation Delay (typical at 5 V) | Approximately 14 ns | Approximately 13 ns | Affects maximum operating frequency and timing margins in synchronous designs. |
| Package | SOIC-16 | SOIC-16 | Physical footprint and pin count must match for PCB layout compatibility. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Ensures reliable operation across industrial and automotive environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC139D | 74HC153D |
|---|---|---|
| Series | 74HC | 74HC |
| Part Status | Obsolete | Active |
| Type | Decoder/Demultiplexer | Multiplexer |
| Circuit | 1 x 2:4 | 2 x 4:1 |
| Independent Circuits | 2 | 2 |
| Current - Output High Low | 5.2mA, 5.2mA | 5.2mA, 5.2mA |
| Voltage Supply Source | Single Supply | Single Supply |
| Voltage - Supply | 2V ~ 6V | 2V ~ 6V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary functional differences between the 74HC153D and the 74HC139D?
The 74HC153D is a dual 4-input multiplexer that selects one of four data inputs per section based on two select lines, while the 74HC139D is a dual 2-to-4 line decoder/demultiplexer that activates one of four outputs based on two address inputs. They serve different logic functions and are not functionally interchangeable.
Are the 74HC153D and 74HC139D pin-compatible?
No. Both are 16-pin SOIC devices, but their pin assignments differ. The 74HC153D has data inputs, select inputs, and multiplexer outputs, whereas the 74HC139D has address inputs and active-LOW decoder outputs. Direct PCB substitution without redesign is not possible.
Can the 74HC153D be used as a replacement for the 74HC139D in a decoder application?
No. The 74HC153D is a multiplexer, not a decoder. It cannot generate the mutually exclusive active-LOW outputs required by a 2-to-4 decoder function. A logic redesign would be necessary to emulate the 74HC139D using a multiplexer.
What are the supply voltage and logic family specifications for both devices?
Both the 74HC153D and 74HC139D are members of the 74HC high-speed CMOS logic family, typically operating from 2.0 V to 6.0 V, with standard CMOS input thresholds and rail-to-rail output swing. Exact limits should be confirmed from the respective manufacturer datasheets.
How do the output configurations of the 74HC153D and 74HC139D differ?
The 74HC153D provides two multiplexer outputs that follow the selected data input, while the 74HC139D provides four active-LOW outputs per decoder section, with only one output LOW at a time based on the address inputs. The output logic polarity and count are fundamentally different.
Which device is better suited for expanding digital I/O or selecting one of multiple data sources?
The 74HC153D is intended for data selection and multiplexing, making it suitable for choosing one of several data sources. The 74HC139D is intended for address decoding and demultiplexing, making it suitable for selecting one of several devices or memory banks. The choice depends on the required logic function.
Do both devices have the same propagation delay and drive characteristics?
Propagation delays and output drive currents are specified per device and can differ based on internal architecture and test conditions. Designers must consult the specific manufacturer datasheet for the 74HC153D and 74HC139D to verify timing and drive parameters for the intended application.