MC145406F - 3-Driver/3-Receiver RS-232 Interface IC | Motorola
MPN: MC145406F ✗ End of LifeMC145406F Overview
An RS-232 interface IC, also called a driver/receiver or transceiver, converts between low-voltage digital logic levels and the voltage levels used by RS-232 links. The MC145406F integrates three transmit channels and three receive channels in one package, reducing component count and simplifying termination around multi-channel communications equipment. Its receiver inputs tolerate negative and positive voltage excursions, while the drivers provide controlled transitions suitable for cable-connected systems.
Key features include true TTL input compatibility, slew-rate-limited driver outputs, a 300 ohm power-off source impedance, and output switching typically to within 25 percent of the supply rails. The silicon-gate CMOS implementation combines low-power operation with the voltage-level translation required by legacy serial communications equipment. The receiver input impedance is specified at 3 to 7 kOhm, allowing multiple line-side inputs to be connected to the receiver circuitry.
The MC145406F is commonly used in RS-232 communications, industrial control equipment, data acquisition systems, printers, terminals, and legacy peripheral interfaces. Its three-driver arrangement can support transmit, handshake, and control channels when the system requires more than one RS-232 output. The three receivers can independently monitor data, status, and handshake lines. The device is especially useful when a design needs a conventional RS-232 interface rather than a modern low-voltage differential standard such as RS-485 or LVDS.
When designing around the MC145406F, account for the voltage polarity of RS-232 signals and include the required external protection, biasing, and connector circuitry recommended by the manufacturer datasheet. Place bypass capacitors close to the supply pins and keep line-side routing away from sensitive logic traces. Confirm that every driver and receiver channel has the correct logic polarity before finalizing the system interface, since the MC145406F is not a protocol controller or level-shifting regulator.
This product page provides the MC145406F datasheet reference, interface architecture, package information, application guidance, and engineering considerations for integrating a three-channel EIA-232-D and CCITT V.28 driver/receiver into communications equipment. It also distinguishes the electrical role of the IC from the surrounding connector, protection, and system-level serial protocol requirements.
Drop-in alternatives for MC145406F — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
MC145406
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC145406B
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC145406V
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC145406E
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC145406F
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →MC145406F Specifications
| Product Type | RS-232 driver/receiver interface IC |
| Driver Channels | 3 |
| Receiver Channels | 3 |
| Interface Standards | EIA-232-D, EIA-232-E, CCITT V.28 |
| Technology | Silicon-gate CMOS |
| Driver Input Compatibility | True TTL input compatible |
| Driver Output Transition | Slew-rate limited |
| Power-Off Source Impedance | 300 ohm |
| Driver Output Switching | Typically within 25% of the supply rails |
| Receiver Input Voltage | Up to plus or minus 25 V |
| Receiver Input Impedance | 3 kOhm to 7 kOhm |
| Number of Pins | 16 pins |
| Package | 16-pin DIP |
| Mounting Type | Through-hole |
MC145406F 16-pin dip Pin Configuration Guide
Pin configuration for MC145406F (16-pin dip package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for MC145406F.
Refer to the datasheet for full pin configuration.
Typical Applications
MC145406F is suitable for 6 applications: Legacy RS-232 Communications, Industrial Control Interfaces, Data Acquisition Systems, Printer and Terminal Equipment, Instrumentation and Test Equipment, RS-232 Handshake and Control Ports.
Legacy RS-232 Communications
The MC145406F is suited to legacy RS-232 communications equipment that needs several line-side channels from one interface IC. Its three drivers and three receivers can support data, status, and handshake paths while the logic-side signals remain TTL-compatible. The receiver section accepts positive and negative line voltages up to plus or minus 25 V, and the driver section provides slew-rate-limited outputs. In a new design, confirm the manufacturer pinout and add the appropriate external protection and bypass components.
Recommended
Industrial Control Interfaces
For industrial control equipment with a legacy RS-232 service port, the MC145406F provides a practical way to add three transmit and three receive channels without using separate single-channel driver and receiver packages. Its silicon-gate CMOS implementation, TTL-compatible driver inputs, and receiver input tolerance make it suitable for equipment that must translate between logic circuitry and RS-232 line levels. The final interface still requires careful grounding, connector selection, and external transient protection for the operating environment.
Recommended
Data Acquisition Systems
The MC145406F can be used in a laboratory or industrial data-acquisition unit that retains an RS-232 control and status interface. Three receiver channels can collect command acknowledgements, status flags, or auxiliary signals, while three driver channels can carry host commands and handshake levels. The receiver impedance of 3 to 7 kOhm and tolerance to plus or minus 25 V are useful in systems with conventional RS-232 voltage levels. Include line protection and verify signal polarity against the system protocol.
Recommended
Printer and Terminal Equipment
Printers, terminals, and other legacy peripherals often use RS-232 for data, status, and flow-control signals. The MC145406F fits these designs when one IC must support multiple channels and a through-hole DIP footprint is acceptable. TTL-compatible driver inputs simplify connection to the host controller, while the receiver channels can monitor peripheral status lines. Because RS-232 uses inverted signaling on many assignments, verify each driver and receiver connection rather than assuming a universal data, status, and handshake arrangement.
Recommended
Instrumentation and Test Equipment
The MC145406F is appropriate for test and measurement instruments that expose a conventional RS-232 configuration port. Its three drivers can support outgoing data, control, and handshake signals, while three receivers can accept remote commands and status feedback. The receiver’s plus-or-minus 25 V input capability handles the RS-232 line environment, and the slew-rate-limited driver outputs help limit unwanted edge content. A grounded shield, connector protection, and correct chassis-to-signal-ground strategy remain important in benchtop systems.
Recommended
RS-232 Handshake and Control Ports
When a system requires more than a single bidirectional data line, the MC145406F can implement separate transmit, receive, and handshake channels. This is useful in older controller arrangements where RTS, CTS, DTR, DSR, and related control signals are implemented separately from data. The three-driver and three-receiver organization keeps the electrical interface compact while preserving the voltage translation required between logic and RS-232 lines. Confirm active polarity and timing requirements for every handshake signal in the system schematic.
Recommended
Recommended Products Summary
Engineering reference data for MC145406F — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC145406 | MC145406B | MC145406V | MC145406E | MC145406F |
|---|---|---|---|---|---|---|
| Package | 16-pin DIP | 16-pin DIP | 16-pin DIP | 16-pin DIP | 16-pin DIP | 16-pin DIP |
| Brand | Motorola | Motorola | Motorola | Motorola | Motorola | Motorola |
| Driver Channels | 3 | 3 | 3 | 3 | 3 | 3 |
| Receiver Channels | 3 | 3 | 3 | 3 | 3 | 3 |
| Interface Standards | EIA-232-D, EIA-232-E, CCITT V.28 | EIA-232-D, EIA-232-E, CCITT V.28 | EIA-232-D, EIA-232-E, CCITT V.28 | EIA-232-D, EIA-232-E, CCITT V.28 | EIA-232-D, EIA-232-E, CCITT V.28 | EIA-232-D, EIA-232-E, CCITT V.28 |
| Receiver Input Voltage | Up to plus or minus 25 V | Up to plus or minus 25 V | Up to plus or minus 25 V | Up to plus or minus 25 V | Up to plus or minus 25 V | Up to plus or minus 25 V |
| Receiver Input Impedance | 3 kOhm to 7 kOhm | 3 kOhm to 7 kOhm | 3 kOhm to 7 kOhm | 3 kOhm to 7 kOhm | 3 kOhm to 7 kOhm | 3 kOhm to 7 kOhm |
| Power-Off Source Impedance | 300 ohm | 300 ohm | 300 ohm | 300 ohm | 300 ohm | 300 ohm |
Key Differentiators
- Three transmitters and three receivers in one package (vs Single-channel RS-232 transceivers)
- Legacy EIA-232 and CCITT compatibility (vs Modern RS-485 or LVDS interfaces)
- Receiver tolerance to RS-232 voltage excursions (vs Logic-level-only receiver circuits)
Design Notes
Route the logic-side signals as ordinary digital interconnects, but keep the RS-232 line-side nets physically separated from sensitive analog and high-speed digital traces. Place the IC near the connector and protection network so transient current from the cable has a short return path. Use a continuous ground reference for the logic side and follow the manufacturer recommended connection arrangement.
Do not treat the MC145406F as a complete RS-232 port. The IC does not replace the DB9 or equivalent connector, transient-protection components, bypass capacitors, or the UART that generates and receives serial data. Also verify signal polarity channel by channel: the logic side and RS-232 line side use opposite conventions for many driver and receiver assignments.
The slew-rate-limited driver outputs help control transition speed, but cable and connector layout still determine radiated noise. Keep the protected line-side section short, use a solid ground plane, and maintain controlled return-current paths. For long or exposed cables, use the protection and grounding arrangement specified by the manufacturer datasheet and the applicable equipment safety standard.
Connect the supply pins with a short, low-impedance path and place the required bypass capacitors close to the device. Check the datasheet for the allowed supply voltage, input-current limits, and output-discharge behavior before selecting external bias resistors. Do not infer a safe supply voltage from the EIA-232 standard alone, because the standard describes the line interface rather than the IC supply rails.
Compliance Information
Compliance information was not stated in the manufacturer datasheet excerpt or the distributor result data.