Part A
74HC245D
Toshiba Semiconductor and Storage
- Lifecycle
- Active
- Stock
- 4218 PCS
- Package
- SOIC-14
- Series
- Lógica - Buffers, Drivers, Receivers, Transceivers
Replacement verdict
Compatible functional replacement candidate
The 74HC245D and 74HC241D,652 are both octal bus transceivers in the same SO-20 package with identical supply voltage and temperature ratings, making the 74HC245D a viable functional substitute for the 74HC241D,652 in most non-critical bus-interface designs. However, the 74HC241D,652 provides non-inverting and inverting output pairs with dual enable inputs, whereas the 74HC245D offers eight non-inverting channels with direction and output-enable control, so logic polarity and control-pin behavior must be validated against the target circuit before substitution.
Package Type
High match
Supply Voltage Range
High match
Output Type
Validation required
Control Logic
Validation required
Parts at a glance
Part B
74HC241D,652
NXP USA Inc.
- Lifecycle
- Active
- Stock
- 2734 PCS
- Package
- SOIC-20
- Series
- Lógica - Buffers, Drivers, Receivers, Transceivers
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74HC245D | 74HC241D,652 | Why it matters |
|---|---|---|---|
| Logic Function | Octal bus transceiver, non-inverting, 3-state | Octal buffer/line driver, non-inverting, 3-state | Determines the core signal-flow behavior; a transceiver supports bidirectional data transfer while a buffer/line driver is unidirectional, affecting whether the parts are functionally interchangeable. |
| Direction Control | Direction pin (DIR) selects A-to-B or B-to-A | Two output-enable pins (1OE, 2OE) control two 4-bit groups; no direction pin | Bidirectional control versus dual enable control changes the pinout and the way the device is driven in a circuit, directly impacting substitutability. |
| Number of Bits | 8 (single 8-bit port pair) | 8 (two independent 4-bit groups) | Although both handle 8 bits, the 74HC241 splits them into two separately enabled 4-bit halves, which affects how enables are wired. |
| Output Enable Configuration | Single OE controlling all 8 outputs | Two separate OEs (1OE, 2OE), each controlling 4 outputs | Independent enable groups allow partial bus control, which the single-enable transceiver cannot provide. |
| Supply Voltage Range | 2.0 V to 6.0 V | 2.0 V to 6.0 V | Matching supply ranges ensure both devices operate in the same logic-level environments. |
| Output Type | 3-state, non-inverting | 3-state, non-inverting | Identical output type means both can share a bus and be placed in high-impedance state. |
| Logic Family | HC (High-speed CMOS) | HC (High-speed CMOS) | Same logic family ensures compatible input thresholds, drive strength, and speed characteristics. |
| Package | SOIC-20 (D suffix) | SO-20 (D suffix) | Both use a 20-pin small-outline package, so board footprint and soldering profile are compatible. |
| Pin Count | 20 | 20 | Same pin count but different pin assignments, so a direct drop-in replacement is not possible without layout changes. |
| Typical Propagation Delay | ~8 ns at 4.5 V | ~8 ns at 4.5 V | Similar delay values indicate comparable timing performance, though exact datasheet limits should be checked for critical timing paths. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74HC245D | 74HC241D,652 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | 74HC | 74HC |
| Part Status | Active | Active |
| Logic Type | Transceiver, Non-Inverting | Buffer, Non-Inverting |
| Number of Elements | 1 | 2 |
| Number of Bits per Element | 8 | 4 |
| Output Type | 3-State | 3-State |
| Current - Output High Low | 7.8mA, 7.8mA | 7.8mA, 7.8mA |
| Voltage - Supply | 2V ~ 6V | 2V ~ 6V |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 125°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the main functional differences between the 74HC245D and the 74HC241D,652?
The 74HC245D is an octal bus transceiver with non-inverting 3-state outputs and a direction control (DIR) pin, allowing data flow in either direction. The 74HC241D,652 is an octal buffer/line driver with non-inverting 3-state outputs, featuring two separate 4-bit enable inputs (1OE and 2OE) but no direction control, so data flows in only one direction.
Are the 74HC245D and 74HC241D,652 pin-compatible?
No. The 74HC245D has a DIR pin (pin 1) and a single output enable (OE) pin (pin 19), while the 74HC241D,652 has two output enable pins (1OE on pin 1 and 2OE on pin 19) and no DIR pin. Their pin functions and control logic differ, so they are not direct drop-in replacements.
Can the 74HC245D be used as a direct substitute for the 74HC241D,652 in an existing design?
Not directly. The 74HC245D provides bidirectional data flow with a DIR pin, whereas the 74HC241D,652 provides unidirectional buffering with two 4-bit enable controls. Substitution requires verifying that the direction control and enable logic are compatible with the target circuit, and may require PCB or firmware changes.
What are the output drive capabilities of the 74HC245D and 74HC241D,652?
Both devices are 74HC-family CMOS octal buffers/transceivers. Standard 74HC specifications typically provide ±6 mA output drive at 5 V VCC, with symmetric source and sink currents. Designers should confirm exact drive strength from the specific manufacturer datasheet, as parameters can vary slightly between vendors.
What supply voltage range do the 74HC245D and 74HC241D,652 support?
Both are 74HC high-speed CMOS devices and typically operate over a supply voltage range of 2.0 V to 6.0 V. This wide range allows use in 3.3 V and 5 V logic systems, but actual limits should be verified against the manufacturer datasheet for the specific part number.
How do the 3-state output enable controls differ between the two devices?
The 74HC245D uses a single active-low output enable (OE) pin that controls all eight outputs simultaneously, plus a DIR pin for direction selection. The 74HC241D,652 uses two active-low enable pins (1OE and 2OE), each controlling a separate 4-bit group of outputs, allowing independent enabling of the two halves.
Which device is more suitable for bidirectional bus applications?
The 74HC245D is specifically designed for bidirectional bus interfacing because it includes a DIR pin that selects transmit or receive mode. The 74HC241D,652 is intended for unidirectional buffering or line driving and cannot reverse data flow, making it unsuitable for bidirectional bus applications without external logic.
Do the 74HC245D and 74HC241D,652 have the same package and pin count?
Both are commonly offered in a 20-pin SOIC package (the "D" suffix typically denotes SOIC). However, despite the same pin count, the pin assignments and functions differ, so they are not interchangeable without verifying the pinout against the respective datasheets.