Part A
74HCT04D
Toshiba Semiconductor et stockage
- Lifecycle
- Active
- Stock
- 4496 PCS
- Package
- SOIC-16
- Series
- Logique - portes et Onduleurs
Replacement verdict
Compatible functional replacement candidate
The 74HCT14D and 74HCT04D are both hex inverter ICs in the same SO-14 package with identical supply voltage and temperature ratings, making them strong functional replacement candidates. However, the 74HCT14D features Schmitt-trigger inputs with hysteresis, while the 74HCT04D has standard unbuffered inverter inputs. This input architecture difference means the 74HCT14D can directly replace the 74HCT04D in most noise-sensitive or slow-edge applications, but the reverse substitution requires careful validation of signal integrity and input rise/fall time requirements.
Logic Function
High match
Package Type
High match
Input Type
Validation required
Supply Voltage
High match
Parts at a glance
Part B
74HCT14D
Toshiba Semiconductor et stockage
- Lifecycle
- Active
- Stock
- 6342 PCS
- Package
- SOIC-14
- Series
- Logique - portes et Onduleurs
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HCT14D | 74HCT04D | Why it matters |
|---|---|---|---|
| Logic Function | Hex inverting Schmitt trigger | Hex inverter | Defines the core function; the Schmitt trigger provides hysteresis, while the plain inverter does not, so they are not functionally interchangeable in noise-sensitive or slow-edge applications. |
| Input Hysteresis (VT+ - VT-) | Typical 0.4 V at VCC = 4.5 V | None (no Schmitt trigger input) | Hysteresis immunizes the input against noise and slow signal edges; its absence in the 74HCT04D can cause oscillation or multiple triggering on slow or noisy inputs. |
| Positive-going Threshold Voltage (VT+) | Typical 1.6 V at VCC = 4.5 V | Not applicable (standard CMOS/TTL threshold) | Determines the input voltage at which the output switches low; the Schmitt trigger has distinct upper and lower thresholds, unlike the single threshold of the plain inverter. |
| Negative-going Threshold Voltage (VT-) | Typical 1.2 V at VCC = 4.5 V | Not applicable (standard CMOS/TTL threshold) | Together with VT+, defines the hysteresis window; the 74HCT04D lacks this separate lower threshold, affecting switching behavior on falling edges. |
| Supply Voltage Range (VCC) | 4.5 V to 5.5 V | 4.5 V to 5.5 V | Both are HCT-family devices designed for 5 V TTL-compatible systems; identical supply range means power-supply compatibility is not a differentiator. |
| Output Drive Current (IOH/IOL) | ±4 mA | ±4 mA | Determines fan-out and ability to drive loads; identical drive strength means either can drive the same loads in terms of current. |
| Propagation Delay (tPD) | Typical 20 ns at VCC = 4.5 V | Typical 15 ns at VCC = 4.5 V | Affects maximum operating frequency and timing margins; the Schmitt trigger is slightly slower due to its hysteresis circuitry. |
| Number of Gates | 6 | 6 | Determines how many independent signal paths are available; both provide six inverters, so channel count is not a differentiator. |
| Package | SO14 (D package) | SO14 (D package) | Physical footprint and pinout must match for drop-in replacement; identical SO14 packages allow the same PCB layout. |
| Input Type | TTL-compatible Schmitt trigger | TTL-compatible CMOS | Both accept TTL-level inputs, but only the 74HCT14D shapes noisy or slow edges via its Schmitt trigger input stage. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HCT04D | 74HCT14D |
|---|---|---|
| Series | 74HCT | 74HCT |
| Part Status | Active | Active |
| Logic Type | Inverter | Inverter |
| Number of Circuits | 6 | 6 |
| Number of Inputs | 1 | 1 |
| Voltage - Supply | 4.5V ~ 5.5V | 4.5V ~ 5.5V |
| Current - Quiescent (Max) | 1 µA | 1 µA |
| Current - Output High Low | 4mA, 4mA | 4mA, 4mA |
| Logic Level - Low | 0.8V | - |
| Logic Level - High | 2V | - |
| Max Propagation Delay @ V Max CL | 16ns @ 5.5V, 50pF | 31ns @ 5.5V, 50pF |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Features | - | Schmitt Trigger |
Frequently asked questions
What is the main functional difference between the 74HCT14D and the 74HCT04D?
The 74HCT14D contains six independent Schmitt-trigger inverters, providing defined switching thresholds and hysteresis for slow or noisy input signals. The 74HCT04D contains six independent standard inverters without Schmitt-trigger hysteresis, intended for clean, fast-edged logic signals.
Are the 74HCT14D and 74HCT04D pin-compatible?
Yes. Both devices are typically offered in the same 14-pin SOIC package (D suffix) with the same pinout: six inverters with inputs on pins 1, 3, 5, 9, 11, and 13, and outputs on pins 2, 4, 6, 8, 10, and 12, with VCC on pin 14 and GND on pin 7.
Can the 74HCT14D be used as a direct drop-in replacement for the 74HCT04D?
In many designs, yes, because the pinout and package are the same and both are HCT-family inverters. However, the 74HCT14D has Schmitt-trigger input thresholds and hysteresis, while the 74HCT04D has standard CMOS input thresholds. The replacement must be validated against the target design's timing, threshold, and noise-margin requirements.
What are the typical input threshold voltages for the 74HCT14D versus the 74HCT04D?
The 74HCT14D, as a Schmitt-trigger device, has positive-going and negative-going threshold voltages with hysteresis, typically specified as VT+ and VT- with a guaranteed hysteresis range in the datasheet. The 74HCT04D has standard HCT input thresholds, typically specified as VIH and VIL at 2.0 V and 0.8 V respectively for 5 V operation. Exact limits should be taken from the respective manufacturer datasheets.
Do both the 74HCT14D and 74HCT04D operate from a 5 V supply?
Yes. Both are HCT-family devices designed for a nominal 5 V supply, with typical operating supply voltage ranges specified in their datasheets, commonly 4.5 V to 5.5 V. They are also TTL-voltage compatible at their inputs.
Which device is better for debouncing a mechanical switch or cleaning up a slow input signal?
The 74HCT14D is better suited for these applications because its Schmitt-trigger inputs provide hysteresis, which helps reject noise and prevents multiple output transitions on slow or noisy edges. The 74HCT04D lacks this hysteresis and may oscillate or produce multiple transitions with slow input signals.
Are the propagation delays of the 74HCT14D and 74HCT04D the same?
No. The propagation delays differ because the Schmitt-trigger input stage of the 74HCT14D introduces additional threshold behavior. Typical propagation delay values are specified separately in each device's datasheet and should be compared for the specific manufacturer and operating conditions.
Do both devices have the same output drive capability?
Both are standard HCT-family logic devices and typically provide similar output drive currents, commonly specified as ±4 mA at 5 V in standard logic families. However, exact output current ratings should be verified from the specific manufacturer datasheet for each part number.