74HC04 Inverter IC: Pinout, Specifications, 74LS04 Comparison, and Replacement Guide

The 74HC04 inverter IC often appears in BOMs, repair boards, prototypes, and digital control circuits, but identifying the part is only the first step. Before using or replacing one, engineers and buyers still need to confirm its pinout, supply voltage, logic thresholds, package, full ordering code, and compatibility with parts such as the 74HCT04 or 74LS04. These details matter because “74HC04” describes a logic function and family, while exact electrical ratings can vary by manufacturer and device version. This guide explains the 74HC04 from practical connection and specification checks through part-number selection and replacement decisions.

What Is the 74HC04 Inverter IC?

The 74HC04 is a high-speed CMOS hex inverter IC from the 74HC logic family. “Hex” means that a single device contains six independent inverter gates. Each gate has one input and one output, and its job is simple: the output changes to the opposite logic state of the input. A logic LOW input therefore produces a logic HIGH output, while a HIGH input produces a LOW output.

In positive logic, each gate performs the Boolean function Y = Ā. Because all six inverters operate independently, a designer can use one, several, or all six gates in the same circuit. This makes the device useful for basic signal inversion, control logic, interface polarity correction, and other general digital logic functions without requiring six separate components.

Input A	Output Y
Low	High
High	Low

The 74HC04 belongs to the CMOS branch of the broader 7400-series logic family. Common 74HC04 versions typically operate from a supply range of about 2 V to 6 V, but that value should be treated as a family-level reference rather than a substitute for the exact manufacturer datasheet. The full ordering code matters when the circuit depends on specific timing, package, temperature, or output-drive requirements.

74HC04 Pinout and Basic Connection

Most familiar 74HC04 versions use a 14-pin layout containing six input/output pairs plus the power and ground pins. In the standard arrangement, pin 14 is VCC and pin 7 is GND. The remaining twelve pins form six independent inverter channels labeled 1A/1Y through 6A/6Y.

Pin	Symbol	Function
1	1A	Inverter 1 input
2	1Y	Inverter 1 output
3	2A	Inverter 2 input
4	2Y	Inverter 2 output
5	3A	Inverter 3 input
6	3Y	Inverter 3 output
7	GND	Ground
8	4Y	Inverter 4 output
9	4A	Inverter 4 input
10	5Y	Inverter 5 output
11	5A	Inverter 5 input
12	6Y	Inverter 6 output
13	6A	Inverter 6 input
14	VCC	Positive supply

To use a single inverter, connect the device supply to pin 14 and ground to pin 7, then feed the logic signal into one of the A pins and read the inverted result from the corresponding Y pin. For example, input 1A on pin 1 is inverted at output 1Y on pin 2. The same relationship applies to the other five gate pairs.

One practical point is especially important with CMOS logic: unused inputs should not normally be left floating. A floating CMOS input can settle at an undefined level, respond to electrical noise, or increase unnecessary switching current. Unused inputs should therefore be tied to a defined valid HIGH or LOW level according to the circuit design. An unused output may remain unconnected if its associated input is properly defined.

The pin arrangement is one of the reasons devices such as 74HC04, 74HCT04, and some related inverter families may appear physically interchangeable. However, matching pin numbers alone does not prove electrical compatibility. Supply range, input thresholds, output behavior, and timing still need to be checked before a replacement is approved.

74HC04 Key Specifications and Electrical Characteristics

The most useful way to read 74HC04 specifications is to separate family-level characteristics from the ratings of a particular manufacturer and ordering code. Competing product pages sometimes present one device’s propagation delay, drive current, or temperature range as though every 74HC04 shared the same number. In practice, exact limits depend on factors such as manufacturer, VCC, output load, temperature, and package.

The table below summarizes the parameters that usually matter most when deciding whether a 74HC04 fits a design.

Parameter	Typical 74HC04 Characteristic	Why It Matters
Logic function	Six independent inverters	Confirms the required logic function
Logic family	High-speed CMOS	Determines logic-level behavior
Supply voltage	Commonly around 2 V to 6 V	Must match the system supply
Number of gates	6	Determines available inverter channels
Input type	Standard CMOS input	Important for input thresholds
Pin count	Commonly 14	Affects board and socket compatibility
Propagation delay	Depends on VCC, load, and device	Determines switching performance
Output drive	Device- and VCC-dependent	Determines what loads can be driven
Operating temperature	Ordering-code dependent	Important for environment and qualification
Package	DIP, SOIC, TSSOP and others	Determines PCB footprint and assembly method

Supply Voltage and Logic Levels

The 74HC family is attractive because it can operate across a wider supply range than traditional LS-TTL logic. Many standard 74HC04 datasheets specify operation from approximately 2 V to 6 V. That flexibility allows the device to work in several common digital supply environments, but it does not mean that every input signal automatically becomes compatible.

The key values to check are VIH and VIL, which define the input voltage guaranteed to be recognized as HIGH or LOW. These thresholds depend on the supply voltage and are part of the reason a 74HC04 should not be treated as identical to a 74HCT04 or 74LS04. A circuit can have matching pinouts and still fail if the driving device does not produce logic levels that satisfy the receiving input thresholds.

Output voltage also needs to be read under the correct conditions. Rather than assuming that the output always equals exactly VCC or 0 V, designers should check VOH and VOL at the relevant output current. This becomes increasingly important when the inverter drives multiple logic inputs or other loads.

Propagation Delay, Output Drive, and Power

Propagation delay describes the time between a change at the input and the corresponding change at the output. A quoted delay figure is meaningful only when the test conditions are known. Supply voltage, load capacitance, temperature, and manufacturer test methods all influence the specified value, so a single number found on a marketplace page should not be applied universally to every 74HC04.

For slower control signals, propagation delay may not be a limiting factor. In faster digital logic, clock paths, or timing-sensitive interfaces, however, the designer should check the manufacturer’s tpd specifications under conditions close to the actual circuit. A device that is functionally correct but too slow can still cause timing failures.

Output drive should be treated the same way. Some product information for 74HC04 devices describes the ability to drive multiple standard logic loads, and certain manufacturer variants are specified to support several LSTTL inputs. The exact source and sink current limits, however, should be taken from the selected datasheet rather than generalized across the entire family.

CMOS technology also gives the 74HC04 relatively low static power consumption compared with older bipolar logic families. Actual system power still increases with switching frequency, load capacitance, supply voltage, and the number of gates toggling, so power should be evaluated in the real operating context rather than from quiescent current alone.

Temperature, Reliability, and Manufacturer Variations

Another source of confusion is operating temperature. Different 74HC04 ordering codes can be intended for different temperature ranges or qualification levels. A value found for one SOIC version cannot automatically be applied to every DIP, TSSOP, automotive, or industrial variant carrying “74HC04” in its name.

The same principle applies to ESD ratings, moisture sensitivity, packaging qualifications, and other reliability data. These characteristics may be highly relevant in production, but they are specific to the manufacturer’s device documentation. For prototype use, a designer may only need the basic operating limits; for industrial or volume production, qualification details become much more important.

A practical rule is therefore to treat 74HC04 as the logic identity, not the final purchasing specification. Once the circuit requirements are known, confirm the full manufacturer part number and then use the datasheet associated with that exact device.

74HC04 Packages, Manufacturers, and Part Numbers

Searching for a 74HC04 often returns several names that appear similar but are not identical: SN74HC04N, SN74HC04DR, 74HC04D, 74HC04PW, MC74HC04, TC74HC04, and others. These variations usually reflect the manufacturer, package style, packing method, temperature grade, or another ordering option rather than a change in the basic six-inverter logic function.

Texas Instruments, Nexperia, onsemi, Toshiba, Diodes Incorporated, and other semiconductor manufacturers have produced devices in the 74HC04 family. Distributor listings may also show a generic “74HC04” under major-brand sourcing, which is why a representative datasheet should not automatically be assumed to describe every possible device supplied under that listing.

Package selection is one of the most visible differences. Through-hole DIP versions are convenient for breadboards, sockets, repair work, and prototyping, while SOIC and TSSOP versions are more suitable for surface-mount production and smaller PCB layouts.

Package Type	Typical Use
DIP-14 / PDIP-14	Breadboards, sockets, through-hole assembly
SOIC-14	General-purpose surface-mount production
TSSOP-14	Space-constrained surface-mount designs
Other compact packages	High-density or manufacturer-specific PCB designs

Suffixes must be interpreted carefully because naming conventions vary between manufacturers. For example, one supplier may use a particular suffix for SOIC while another uses a different code for the same general package family. Packing options such as tube versus tape-and-reel may add yet another suffix without changing the underlying electrical function.

For this reason, procurement should never stop at “74HC04.” A production BOM should ideally contain the full manufacturer part number, package, required temperature grade, and any qualification requirements. That level of detail becomes even more important when a proposed alternative comes from another logic family rather than simply another manufacturer of the same 74HC04 function.

74HC04 vs 74HCT04, 74LS04, 74HC14, and Other Alternatives

Once the basic specifications and package are understood, the next question is often whether another hex inverter can replace the 74HC04. This is where part-number similarity can be misleading. The 74HC04, 74HCT04, 74LS04, 74HC14, and CD4069 all perform signal inversion in some form, but their input thresholds, supply requirements, switching behavior, and underlying logic families are not identical.

The most important replacement rule is simple: matching logic function and pinout are not enough. A substitute also needs to work with the voltage levels, timing requirements, package, temperature range, and load conditions of the original circuit.

Device	Logic / Input Type	Main Difference from 74HC04	Replacement Consideration
74HC04	High-speed CMOS	Standard CMOS hex inverter	Reference device
74HCT04	CMOS with TTL-compatible inputs	Different input thresholds and supply range	Check VCC and input levels
74LS04	TTL	Different logic technology and electrical characteristics	Not automatically interchangeable
74HC14	CMOS Schmitt-trigger inverter	Adds hysteresis to inputs	Different input behavior
CD4069	CMOS hex inverter	Different logic family, voltage and timing characteristics	Verify full datasheet

74HC04 vs 74HCT04

The 74HC04 and 74HCT04 provide the same basic function: six independent inverters. The important difference is their input behavior. The 74HC04 uses CMOS-compatible input thresholds, while the 74HCT04 is designed with TTL-compatible input levels. This makes the HCT version useful when a CMOS logic device needs to receive signals from circuitry that produces conventional TTL-level outputs.

Their recommended supply conditions also differ. Standard HC devices generally support a broader supply range, while HCT devices are intended primarily for operation around 5 V. Therefore, a 74HCT04 should not be substituted simply because its pinout and logic function match a 74HC04.

In a 5 V circuit driven by TTL-compatible logic, a 74HCT04 may be the more appropriate choice. In a lower-voltage CMOS system, however, the 74HC04 may be suitable while the 74HCT04 is not. The actual decision should be based on the manufacturer datasheets for both exact parts.

74HC04 vs 74LS04

The 74LS04 inverter IC also contains six NOT gates, but it belongs to the LS-TTL family rather than the CMOS HC family. That difference affects supply voltage, input thresholds, current characteristics, and power consumption. The 74LS04 is normally associated with 5 V TTL systems, whereas the 74HC04 supports a broader CMOS supply range.

This is a practical example of why a CMOS inverter vs TTL inverter comparison cannot be reduced to pin compatibility. A TTL output that is considered a valid HIGH within an LS system may not always meet the HIGH-level requirement of a CMOS HC input under every supply condition. Similarly, current sourcing and sinking behavior differs between the two logic technologies.

If an older board uses a 74LS04 and a 74HC04 is proposed as a replacement, the designer should check both sides of every interface rather than only the inverter itself. The driving device must satisfy the HC input thresholds, while the HC output must also meet the requirements of the downstream circuit.

74HC04 vs 74HC14

The difference between the 74HC04 and 74HC14 is especially important because both are CMOS hex inverters, but the 74HC14 uses Schmitt-trigger inputs. A Schmitt-trigger inverter introduces hysteresis, meaning the voltage threshold for switching from LOW to HIGH differs from the threshold for switching back from HIGH to LOW.

That behavior makes a 74HC14 more suitable for slowly changing, noisy, or imperfect input signals. A standard 74HC04 is intended for normal digital transitions and should not generally be described as a Schmitt-trigger inverter. This distinction matters when selecting a device for sensor signals, RC networks, switches, or other sources that may not provide a clean digital edge.

The 74HC14 can therefore solve problems that a standard 74HC04 may not handle as reliably, but the two devices should not be considered electrically identical simply because both invert logic signals. The required input behavior should determine which device is appropriate.

How to Check a 74HC04 Replacement

When the original part is unavailable, start by confirming that the candidate performs the same six-inverter logic function. Then compare the pinout and package, followed by the electrical characteristics that affect the actual circuit. A practical replacement check should include supply voltage, VIH/VIL thresholds, output drive, propagation delay, package footprint, operating temperature, and qualification requirements.

The same process applies when considering less direct alternatives such as the CD4069 or another 7404-family inverter. A device may look similar in a schematic yet behave differently because it belongs to another logic family. For production replacement, the safest approach is to compare the original and proposed datasheets under the same operating conditions before approving a BOM change.

Common Uses of the 74HC04

The most direct use of a 74HC04 is logic signal inversion. A control signal that is active HIGH can be converted to active LOW, or vice versa, without changing the rest of the logic path. This makes the device useful as simple “glue logic” between digital blocks when a signal polarity does not match what the next stage expects.

The same principle appears in interface and control circuits. Practical applications include inverting UART or other digital interface signals, changing sensor-output polarity, or generating complementary control signals. Real-world users also employ 74HC04 devices in prototypes and repair circuits where an existing digital signal needs to be inverted before reaching a controller or peripheral.

Inverters can also appear in simple oscillator or timing circuits, but this use requires more care. Standard 74HC04 inputs are not Schmitt-trigger inputs, so circuits that intentionally use slow RC transitions may be better suited to devices such as the 74HC14. The inverter should therefore be chosen for the electrical behavior required by the circuit, not simply because both devices can generate a logical NOT function.

How to Select and Buy the Right 74HC04

Once the decision to use a 74HC04 has been made, selection should begin with the full manufacturer part number, not the generic family name alone. Confirm the intended manufacturer, package, supply voltage, logic-level compatibility, switching speed, output-load requirements, and operating temperature. If the part is going onto an existing PCB, the package and footprint must also match the board layout.

For prototype work, a DIP-14 device may be convenient because it can be used with sockets and breadboards. For production assemblies, SOIC, TSSOP, or another surface-mount package may be more practical. Volume production can introduce additional requirements such as tape-and-reel packaging, moisture sensitivity, lifecycle status, and qualification grade.

Replacement sourcing adds another layer. If the original manufacturer or ordering code is unavailable, confirm that the proposed alternative is electrically compatible rather than relying on the shared “74HC04” name. For maintenance and production procurement, supplier traceability and component authenticity are also important because substituted or incorrectly marked logic devices can create difficult-to-diagnose failures.

For BOM review, part-number verification, or compatible-alternative evaluation, China Chip Depot can support component sourcing and replacement review before a purchasing decision is finalized.

How to Read a 74HC04 Datasheet Before Finalizing a Design

A 74HC04 datasheet should be used as the final technical reference rather than as a source of isolated headline numbers. The first items to confirm are the recommended supply voltage and operating temperature, followed by input thresholds such as VIH and VIL and output characteristics such as VOH, VOL, IOH, and IOL.

For timing-sensitive designs, check propagation delay at the actual or nearest available VCC and load capacitance. Also review the package drawing and ordering information before completing PCB layout or purchasing. Absolute maximum ratings are useful for understanding device limits, but they are not the same as recommended operating conditions and should not be treated as normal design targets.

Most importantly, make sure the datasheet corresponds to the exact manufacturer and full ordering code being evaluated. A generic or representative 74HC04 datasheet is useful for understanding the family, but it may not contain the precise package, temperature, timing, or qualification data required for a specific production part.

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