Part A
74HCT04D
Toshiba Semiconductor và lưu trữ
- Lifecycle
- Active
- Stock
- 4496 PCS
- Package
- SOIC-16
- Series
- Logic - Gates and Inverters
Replacement verdict
Not a drop-in replacement
The 74HCT04D and 74HCT7273D,118 are functionally unrelated devices and cannot be used interchangeably. The 74HCT04D is a hex inverting gate, while the 74HCT7273D,118 is a dual 4-bit shift register with output latches. They differ in logic function, channel count, pinout, and package type, making direct substitution impossible without a complete circuit redesign.
Different logic function
Different channel count
Different pinout
Different package type
Parts at a glance
Part B
74HCT7273D,118
NXP Hoa Kỳ Inc.
- Lifecycle
- Active
- Stock
- 4249 PCS
- Series
- Logic - Flip Flops
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HCT04D | 74HCT7273D,118 | Why it matters |
|---|---|---|---|
| Logic Function | Hex Inverter | Octal D-Type Flip-Flop with Reset | The fundamental logic function determines whether the parts can substitute for each other in a circuit; an inverter and a flip-flop perform completely different operations. |
| Number of Circuits / Channels | 6 | 8 | Channel count affects how many independent signal paths can be handled, impacting board layout and whether one IC can replace another. |
| Output Type | Push-Pull (Standard CMOS) | Push-Pull (Standard CMOS) | Output drive configuration must match the load and bus topology; both are push-pull but the flip-flop adds registered outputs. |
| Propagation Delay (tpd) | ~14 ns at 4.5 V | ~20 ns at 4.5 V | Propagation delay determines maximum operating frequency and timing margins in synchronous designs. |
| Supply Voltage Range | 4.5 V to 5.5 V | 4.5 V to 5.5 V | Both are HCT-family devices requiring a 5 V nominal supply; voltage compatibility is essential for direct substitution. |
| Package / Mounting | SO-14 (Surface Mount) | SO-20 (Surface Mount) | Different pin counts and package footprints prevent direct drop-in replacement without PCB redesign. |
| Clock Input | None (combinational) | Yes (edge-triggered) | Presence of a clock input means the flip-flop stores state, while the inverter is purely combinational, fundamentally changing circuit behavior. |
| Reset Function | None | Asynchronous Reset | A reset pin allows deterministic initialization of outputs, which is critical in sequential logic but absent in simple inverters. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Both meet industrial temperature requirements, so thermal compatibility is not a differentiator. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HCT04D | 74HCT7273D,118 |
|---|---|---|
| Supplier | - | NXP USA Inc. |
| Series | 74HCT | 74HCT |
| Part Status | Active | Obsolete |
| Function | - | Master Reset |
| Type | - | D-Type |
| Output Type | - | Non-Inverted |
| Number of Elements | - | 1 |
| Number of Bits per Element | - | 8 |
| Clock Frequency | - | 56 MHz |
| Max Propagation Delay @ V Max CL | 16ns @ 5.5V, 50pF | 30ns @ 4.5V, 50pF |
| Trigger Type | - | Positive Edge |
| Current - Output High Low | 4mA, 4mA | -, 4mA |
| Voltage - Supply | 4.5V ~ 5.5V | 4.5V ~ 5.5V |
| Current - Quiescent (Iq) | - | 8 µA |
| Input Capacitance | - | 3.5 pF |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Logic Type | Inverter | - |
| Number of Circuits | 6 | - |
| Number of Inputs | 1 | - |
| Current - Quiescent (Max) | 1 µA | - |
| Logic Level - Low | 0.8V | - |
| Logic Level - High | 2V | - |
Frequently asked questions
Are the 74HCT04D and 74HCT7273D,118 functionally interchangeable?
No. The 74HCT04D is a hex inverter providing six independent NOT gates, while the 74HCT7273D,118 is an octal D-type flip-flop with clear, featuring eight edge-triggered registers. Their logic functions, pin counts, and internal architectures are fundamentally different, so they cannot be used as substitutes for one another.
What are the primary logic functions of each device?
The 74HCT04D contains six independent inverters that output the logical complement of each input. The 74HCT7273D,118 contains eight D-type flip-flops that capture input data on the rising edge of the clock and provide the stored state at their outputs, with an asynchronous clear input to reset all registers.
How do the package types and pin counts differ between the two parts?
The 74HCT04D is supplied in a 14-pin SOIC package (D suffix). The 74HCT7273D,118 is supplied in a 20-pin SOIC package (D suffix) with the ,118 indicating tape-and-reel packing. The different pin counts reflect the higher I/O count of the octal flip-flop.
Do both devices operate from the same supply voltage range?
Yes. Both are HCT-family logic devices specified for a nominal 5 V supply, with a recommended operating supply voltage range of 4.5 V to 5.5 V. They are also characterized for TTL-compatible input thresholds when used at 5 V.
Can the 74HCT04D be used to drive the clock or clear inputs of the 74HCT7273D,118?
Yes, provided the system timing and fan-out are respected. The 74HCT04D outputs are standard HCT CMOS outputs capable of driving HCT-family inputs. However, the inverter introduces propagation delay and inversion, so the polarity and timing of the clock or clear signal must be accounted for in the design.
What is the difference in maximum operating frequency between these two devices?
The 74HCT04D is an unbuffered combinational inverter and does not have a specified maximum operating frequency in the same sense as a sequential logic device; its speed is characterized by propagation delay. The 74HCT7273D,118, as a flip-flop, has a specified maximum clock frequency, typically 50 MHz or higher for HCT-type devices at 5 V, depending on the manufacturer. Always consult the specific manufacturer datasheet for the exact limit.
Are the input and output voltage levels compatible between the two devices?
Yes. Both devices are HCT-type, meaning they accept TTL-level input voltages (VIH ≥ 2.0 V, VIL ≤ 0.8 V) when operating at 5 V and produce CMOS-level outputs (VOH ≥ 4.4 V, VOL ≤ 0.1 V typical). This makes them directly compatible in mixed 5 V TTL/CMOS systems.
Which device is more suitable for edge-triggered data storage applications?
The 74HCT7273D,118 is the correct choice for edge-triggered data storage because it contains octal D-type flip-flops that latch data on a clock edge. The 74HCT04D is purely combinational and cannot store state; it is used for signal inversion, buffering, or waveform shaping.