Part A
74HC164D
Toshiba Semiconductor et stockage
- Lifecycle
- Active
- Stock
- 2726 PCS
- Package
- SOIC-8
- Series
- Logique - Registre à décalage
Replacement verdict
Not a drop-in replacement
The 74HC164D and 74HC154D,653 are functionally unrelated logic ICs and cannot serve as substitutes for one another. The 74HC164D is an 8-bit serial-in/parallel-out shift register, while the 74HC154D,653 is a 4-to-16 line decoder/demultiplexer. Their internal architectures, pin functions, and intended applications differ fundamentally, so neither device can directly replace the other in an existing design without significant circuit redesign.
Different logic function
Different pin function
Different input/output topology
Different application role
Parts at a glance
Part B
74HC154D,653
NXP USA Inc.
- Lifecycle
- Active
- Stock
- 4133 PCS
- Package
- SOIC-24
- Series
- Logique - commutateurs de signaux, multiplexeurs, décodeurs
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC164D | 74HC154D,653 | Why it matters |
|---|---|---|---|
| Logic Function | 8-bit serial-in/parallel-out shift register | 4-to-16 line decoder/demultiplexer | The core logic function determines whether the devices are functionally interchangeable; these two perform entirely different operations. |
| Number of Outputs | 8 | 16 | Output count affects how many loads or lines the device can drive in a system. |
| Number of Inputs | 2 (data + clock) | 4 (address) plus 2 enable inputs | Input count and type dictate the control interface and addressing capability of the device. |
| Output Type | Push-pull (totem-pole) | Active-low outputs | Output polarity and drive style determine compatibility with downstream logic and loads. |
| Package | SO-14 (SOIC-14) | SO-24 (SOIC-24) | Package footprint and pin count must match the PCB layout for a drop-in replacement. |
| Pin Count | 14 | 24 | Different pin counts mean the devices are not pin-compatible and cannot be swapped directly. |
| Supply Voltage Range | 2 V to 6 V | 2 V to 6 V | Both operate over the standard HC-family supply range, so voltage compatibility is equivalent. |
| Logic Family | 74HC (high-speed CMOS) | 74HC (high-speed CMOS) | Same logic family ensures comparable input/output thresholds and noise margins. |
| Propagation Delay (typical) | Approximately 14 ns at 5 V | Approximately 15 ns at 5 V | Propagation delay influences maximum operating speed and timing margins in synchronous designs. |
| Primary Application | Serial-to-parallel data conversion, LED driving, I/O expansion | Address decoding, memory/chip-select decoding, demultiplexing | Intended application highlights that these parts serve fundamentally different roles and are not substitutes. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC164D | 74HC154D,653 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | 74HC | 74HC |
| Part Status | Active | Active |
| Type | - | Decoder/Demultiplexer |
| Circuit | - | 1 x 4:16 |
| Independent Circuits | - | 1 |
| Current - Output High Low | - | 5.2mA, 5.2mA |
| Voltage Supply Source | - | Single Supply |
| Voltage - Supply | 2V ~ 6V | 2V ~ 6V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Logic Type | Shift Register | - |
| Output Type | Push-Pull | - |
| Number of Elements | 1 | - |
| Number of Bits per Element | 8 | - |
| Function | Serial to Parallel | - |
Frequently asked questions
What are the primary functional differences between the 74HC164D and the 74HC154D,653?
The 74HC164D is an 8-bit serial-in/parallel-out shift register, while the 74HC154D,653 is a 4-to-16 line decoder/demultiplexer. The 74HC164D shifts serial data into eight parallel outputs, whereas the 74HC154D decodes a 4-bit binary input into one of sixteen mutually exclusive active-LOW outputs.
Are the 74HC164D and 74HC154D,653 pin-compatible?
No. The 74HC164D is typically supplied in a 14-pin SOIC package, while the 74HC154D,653 is supplied in a 24-pin SOIC package. They have different pin counts, pin functions, and PCB land patterns, so they are not pin-compatible or directly interchangeable.
Can the 74HC164D and 74HC154D,653 operate from the same supply voltage?
Yes. Both devices are 74HC-family CMOS logic parts and are specified for a nominal supply voltage range of 2.0 V to 6.0 V, with 5 V being the most common operating voltage. However, individual datasheet limits and timing parameters should always be verified for the specific manufacturer and operating conditions.
What is the difference in output count and output type between these two devices?
The 74HC164D provides eight parallel outputs that follow the serial input data and are not mutually exclusive. The 74HC154D,653 provides sixteen active-LOW outputs, of which only one is asserted at a time based on the 4-bit address input, making it suitable for decoding and demultiplexing applications.
Which device is better suited for expanding microcontroller I/O?
The 74HC164D is typically used to expand outputs serially, requiring only two control lines (data and clock) to drive eight outputs. The 74HC154D,653 is used to select one of sixteen outputs from a 4-bit address, which is useful for address decoding or chip-select generation rather than general-purpose I/O expansion.
Do both devices have the same logic family and input threshold characteristics?
Yes. Both are 74HC high-speed CMOS devices, so they share standard 74HC input threshold ratios and CMOS-compatible input/output characteristics when operated at the same supply voltage. Exact switching thresholds, propagation delays, and drive currents should be confirmed from the respective manufacturer datasheets.
Can the 74HC164D be used as a drop-in replacement for the 74HC154D,653 in an existing design?
No. Because the two devices have different functions, pin counts, packages, and output logic, a direct drop-in replacement is not possible. Any substitution would require a complete redesign of the surrounding circuitry, including pin mapping, control signals, and output loading considerations.