Part A
74HC164D
Toshiba Semiconductor and Storage
- Lifecycle
- Active
- Stock
- 2726 PCS
- Package
- SOIC-8
- Series
- Logic - Shift Registers
Replacement verdict
Not a drop-in replacement
The 74HC164D and 74HC154D,652 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,652 is a 4-to-16 line decoder/demultiplexer. Their internal architectures, pin functions, and application roles differ fundamentally, so neither device can directly replace the other in an existing design.
Different logic function
Different input type
Different output type
Different pinout
Parts at a glance
Part B
74HC154D,652
NXP USA Inc.
- Lifecycle
- Active
- Stock
- 2528 PCS
- Package
- SOIC-24
- Series
- Logic - Signal Switches, Multiplexers, Decoders
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,652 | 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 parallel outputs | 16 outputs (active LOW) | Output count affects how many loads or lines the device can drive in a system design. |
| Number of Inputs | 2 (data + clock) | 4 address inputs plus 2 enable inputs | Input count and type dictate the control interface and addressing capability of the device. |
| Output Type | Push-pull (totem-pole) CMOS outputs | Active LOW outputs | Output polarity and drive style affect signal compatibility with downstream logic. |
| Package / Mounting | SOIC-14 surface mount | SOIC-24 surface mount | Package footprint and pin count must match the PCB layout for physical substitutability. |
| Pin Count | 14 pins | 24 pins | Different pin counts mean the devices are not drop-in replacements on the same footprint. |
| Supply Voltage Range | 2.0 V to 6.0 V | 2.0 V to 6.0 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 thresholds, noise margins, and interfacing behavior. |
| Propagation Delay (typical) | Approximately 20 ns at 4.5 V | Approximately 20 ns at 4.5 V (enable to output) | Timing characteristics influence maximum operating frequency and signal integrity in synchronous designs. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Temperature range determines suitability for industrial and automotive environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC164D | 74HC154D,652 |
|---|---|---|
| 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,652?
The 74HC164D is an 8-bit serial-in/parallel-out shift register, while the 74HC154D,652 is a 4-to-16 line decoder/demultiplexer. The 74HC164D shifts serial data into eight parallel outputs, whereas the 74HC154D,652 decodes a 4-bit binary input into one of sixteen mutually exclusive active-LOW outputs.
Are the 74HC164D and 74HC154D,652 pin-compatible?
No. The 74HC164D is typically supplied in a 14-pin SOIC package, while the 74HC154D,652 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,652 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 5.0 V being the most common operating voltage in legacy and mixed-signal designs.
What is the logic function of the 74HC164D?
The 74HC164D is an 8-bit serial-in/parallel-out shift register with two serial data inputs (A and B) that are ANDed internally. Data is shifted on the LOW-to-HIGH transition of the clock (CP), and an asynchronous master reset (MR) clears all eight parallel outputs to LOW.
What is the logic function of the 74HC154D,652?
The 74HC154D,652 is a 4-to-16 line decoder/demultiplexer. It accepts a 4-bit binary address (A0–A3) and, when both enable inputs (E1 and E2) are LOW, pulls exactly one of the sixteen outputs (Y0–Y15) LOW while all other outputs remain HIGH.
Which device is better suited for expanding microcontroller I/O outputs?
The 74HC164D is generally used to expand outputs serially, requiring only two or three microcontroller pins to drive eight outputs. The 74HC154D,652 is used when a 4-bit address must select one of sixteen outputs, such as in memory or peripheral chip-select decoding. The choice depends on whether serial shifting or binary address decoding is required.
Do both devices have the same output drive capability?
Both are 74HC-family devices and typically provide standard CMOS output drive, commonly specified as ±4 mA at 5 V VCC for balanced outputs. However, the 74HC154D,652 outputs are active-LOW decoder outputs, while the 74HC164D outputs are standard push-pull parallel register outputs. Actual drive current should always be confirmed from the specific manufacturer datasheet.
Are the 74HC164D and 74HC154D,652 drop-in replacements for one another in an existing design?
No. Because they differ in function, pin count, package size, and pinout, they cannot be used as drop-in replacements. A redesign of the schematic, PCB footprint, and control firmware or logic would be required to substitute one for the other.