Part A
74VHC245FT
Toshiba Semiconductor et stockage
- Lifecycle
- Active
- Stock
- 4188 PCS
- Package
- TSSOP-20
- Series
- Logique - Buffers, lecteurs, récepteurs, émetteurs - récepteurs
Replacement verdict
Not a drop-in replacement
The 74VHC245FT and 74VHC00FT are not functionally interchangeable. The 74VHC245FT is an octal bus transceiver with 3-state outputs and dual enable controls, while the 74VHC00FT is a quad 2-input NAND gate. Their logic functions, channel configurations, pin assignments, and control interfaces are fundamentally different, making direct substitution impossible without complete circuit redesign.
Different logic function
Different channel count
Different pin assignment
Different control interface
Parts at a glance
Part B
74VHC00FT
Toshiba Semiconductor et stockage
- Lifecycle
- Active
- Stock
- 3159 PCS
- 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 | 74VHC245FT | 74VHC00FT | Why it matters |
|---|---|---|---|
| Logic Function | Octal bidirectional transceiver with 3-state outputs | Quad 2-input NAND gate | Defines the fundamental logic operation; these devices are not functionally interchangeable. |
| Number of Channels | 8 | 4 | Determines how many independent signal lines can be processed simultaneously. |
| Direction Control | Bidirectional (DIR pin selects A-to-B or B-to-A) | Unidirectional (fixed logic inputs to output) | Affects whether the device can route signals in both directions on a bus. |
| Output Type | 3-state (tri-state) outputs with OE control | Standard push-pull CMOS outputs | Tri-state outputs allow bus sharing; push-pull outputs cannot be tied together. |
| Propagation Delay (tpd) | Approximately 4.5 ns at 5 V | Approximately 4.3 ns at 5 V | Impacts maximum operating frequency and timing margins in synchronous systems. |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | Determines compatibility with 3.3 V and 5 V logic systems. |
| Output Drive Current | ±8 mA at 5 V | ±8 mA at 5 V | Sets the fan-out capability and ability to drive loads or transmission lines. |
| Package | TSSOP-20 | TSSOP-14 | Footprint and pin count affect PCB layout and cannot be directly substituted. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Ensures reliable operation across industrial and commercial environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74VHC245FT | 74VHC00FT |
|---|---|---|
| Supplier | - | Toshiba Semiconductor and Storage |
| Series | 74VHC | TC74VHC |
| Part Status | Active | Active |
| Logic Type | Transceiver, Non-Inverting | NAND Gate |
| Number of Circuits | - | 4 |
| Number of Inputs | - | 2 |
| Voltage - Supply | 2V ~ 5.5V | 2V ~ 5.5V |
| Current - Quiescent (Max) | - | 2 µA |
| Current - Output High Low | 8mA, 8mA | 8mA, 8mA |
| Logic Level - Low | - | 0.5V |
| Logic Level - High | - | 1.5V |
| Max Propagation Delay @ V Max CL | - | 7.5ns @ 5V, 50pF |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Number of Elements | 1 | - |
| Number of Bits per Element | 8 | - |
| Output Type | 3-State | - |
Frequently asked questions
What are the primary functional differences between the 74VHC245FT and the 74VHC00FT?
The 74VHC245FT is an octal bidirectional transceiver with 3-state outputs, designed for bus-oriented data transmission. The 74VHC00FT is a quad 2-input NAND gate, designed for logic gating functions. They serve fundamentally different roles and are not functionally interchangeable.
Are the 74VHC245FT and 74VHC00FT pin-compatible?
No. The 74VHC245FT is typically supplied in a 20-pin package (e.g., TSSOP20), while the 74VHC00FT is typically supplied in a 14-pin package (e.g., TSSOP14). Pin counts, pin assignments, and package footprints differ, so they cannot be used as drop-in replacements for each other.
Do both devices operate from the same supply voltage range?
Yes. Both the 74VHC245FT and 74VHC00FT are VHC-family CMOS devices and operate from a supply voltage range of 2.0 V to 5.5 V, as specified in the respective manufacturer datasheets.
Can the 74VHC245FT be used to drive a bus while the 74VHC00FT performs logic decoding on the same board?
Yes. Because they perform different functions, they are often used together in the same system. The 74VHC245FT handles bidirectional bus buffering and isolation, while the 74VHC00FT implements NAND-based logic functions. Their common VHC-family supply and logic-level compatibility support mixed use in a single design.
What is the difference in output drive capability between the 74VHC245FT and the 74VHC00FT?
Both devices are VHC-family parts and typically provide symmetrical output drive of ±8 mA at 5 V, as stated in manufacturer datasheets. However, the 74VHC245FT includes 3-state control for bus isolation, while the 74VHC00FT provides standard push-pull logic outputs without 3-state capability.
Are the 74VHC245FT and 74VHC00FT interchangeable in an existing PCB layout?
No. They differ in function, pin count, and package footprint. Substitution would require a complete redesign of the circuit and PCB layout, not a direct replacement.
Do both devices support the same operating temperature range?
Both the 74VHC245FT and 74VHC00FT are typically specified for the industrial temperature range of −40 °C to +85 °C or −40 °C to +125 °C, depending on the exact manufacturer suffix. Designers should confirm the specific ordering part number and datasheet for the exact temperature grade required.