SN75123D - Dual TTL Line Driver | Texas Instruments
MPN: SN75123D ✓ NakahandaSN75123D Ulas
A line driver is a digital interface IC that converts logic-level inputs into stronger output signals capable of driving terminated cables, coaxial links, or twisted-pair lines. The dual SN75123 belongs to the line-driver and receiver class of interface ICs. Its primary role is to improve signal integrity and drive capability across long or shared bus wiring rather than to perform data conversion or voltage regulation.
The SN75123D operates from one 5 V supply and is compatible with standard-TTL logic levels. Its emitter-follower outputs are designed for low-impedance line driving and support party-line operation, where multiple drivers can share a bus when their outputs are appropriately controlled. The output structure also provides short-circuit protection, a useful characteristic when a connected line is faulted or incorrectly terminated.
The 3.11 V output level at -59.3 mA indicates strong high-level output drive capability. With a maximum transmit delay of 25 ns, the device supports communication systems that require faster edge propagation than general-purpose logic buffers. The manufacturer identifies the SN75123 family as meeting or exceeding the IBM System 360 input/output interface requirements while remaining compatible with standard-TTL supply and logic levels.
Typical uses include terminated coaxial cable links, twisted-pair communication channels, computer peripheral interfaces, industrial data links, and legacy equipment built around TTL or IBM System 360 interfaces. Because the outputs use an uncommitted emitter-follower structure, designers can implement party-line networks in which connected drivers share the same physical conductor.
For a new design, verify the receiver's threshold requirements, line termination, cable length, and grounding arrangement before assigning the driver. The 16-pin SOIC package simplifies assembly and rework, but the output enable, input, ground, and supply pins must be connected according to the manufacturer datasheet. A single 5 V rail and common ground reference are fundamental to reliable operation.
This product page combines the manufacturer's functional description with engineering-focused comparison, application, and design guidance. It also clearly distinguishes directly substitutable components from candidates that require different packages or interfaces, helping engineers preserve PCB compatibility when planning replacements or design reuse.
Mga alternatibo na pwedeng ilagay na SN75123D — parehas na package, pin-to-pin na katugmang. Hindi kasama ang mga bahagi ng iba't-ibang package na nangangailangan ng pagpapaayos ng PCB.
Wala ng magagamit na drop-in alternatibo para sa produkto na ito.
Hilingin ang AlternatiboSN75123D Mga Spesipikasyon
| Product Type | Dual line driver |
| Number of Drivers | 2 channels |
| Volte ng Pagbibigay | 5 V |
| Maximum Supply Voltage | 5.25 V |
| Logic Compatibility | Standard TTL |
| Interface Standard | IBM System 360 input/output interface |
| Output Volte | 3.11 V at -59.3 mA |
| Maximum Transmit Delay | 25 ns |
| Maximum Supply Current | 60 mA |
| Output Structure | Uncommitted emitter-follower |
| Party-Line Operation | Supported |
| Short-Circuit Protection | Yes |
| Packhaging | 16-pin SOIC |
| Uri ng Pagpapasok | Surface mount |
| Terminal Count | 16 terminals |
Gabay sa Pin Configuration ng SN75123D 16-pin soic
Pin configuration para sa SN75123D (16-pin soic package). Ang pagnunumero ng pin, mga function, at connection diagram ay tinukoy sa datasheet ng manufacturer. Sumangguni dito para sa eksaktong footprint at mga alituntunin sa soldering.
Wala ng detalyadong pinout data na magagamit para sa SN75123D.
Sumangguni sa datasheet para sa buong pin configuration.
Tipikal na mga Gamit
SN75123D ay nararapat para sa 6 aplikasyons: Terminated Coaxial Data Links, Twisted-Pair Communication Channels, IBM System 360 Legacy Interfaces, Party-Line Peripheral Buses, Industrial Data Acquisition, Test and Measurement Interfaces.
Terminated Coaxial Data Links
The SN75123D is appropriate for terminated coaxial data links because its dual emitter-follower outputs provide low-impedance drive for cable-connected receivers. The manufacturer specifies a 3.11 V output at -59.3 mA and a maximum transmit delay of 25 ns, allowing the device to retain useful signal strength and timing performance across a designed line. The transmitter operates from one 5 V supply and is compatible with standard-TTL inputs. In implementation, the cable characteristic impedance, receiver input loading, shield connection, and source termination should be evaluated together because the device does not create an appropriate termination by itself.
Inirekomenda
Twisted-Pair Communication Channels
The SN75123D can drive twisted-pair communication channels where the system requires a single-ended TTL-compatible interface and stronger source drive than standard logic provides. Its low-impedance emitter-follower outputs are specifically described for terminated lines, while short-circuit protection helps contain fault conditions on an externally routed conductor. With a maximum transmit delay of 25 ns, the device is suitable for moderate-speed communication links. PCB implementation should provide a continuous return path, proper line termination, and clean separation between the two driver channels to limit crosstalk.
Inirekomenda
IBM System 360 Legacy Interfaces
The SN75123D was designed specifically for IBM System 360 input/output interface requirements and is therefore relevant to equipment that retains this legacy electrical interface. It operates from a single 5 V supply, accepts standard-TTL-compatible signals, and provides two independent line-driver channels for terminated conductors. The 3.11 V output at -59.3 mA supports the stronger signaling expected by this interface class. When modernizing legacy equipment, preserve the original termination and receiver arrangement unless a complete signal-integrity review establishes that the interface can be adapted safely.
Inirekomenda
Party-Line Peripheral Buses
The SN75123D fits party-line peripheral buses because its uncommitted emitter-follower outputs allow multiple connected drivers to share one conductor when their enables are sequenced correctly. This architecture suits legacy backplane and peripheral arrangements in which every attached transmitter can be placed in a high-impedance state. Short-circuit protection improves robustness when a connected line is faulted. Timing must still prevent two enabled drivers from driving the bus in opposite states, and the system designer should validate contention behavior, receiver thresholds, and cable fall time before production use.
Inirekomenda
Industrial Data Acquisition
The SN75123D can serve as the line transmitter in industrial data-acquisition equipment that uses a legacy 5 V TTL-compatible cable interface. Its two channels reduce the component count for dual-line links, while the stated 25 ns maximum transmit delay supports communication at speeds substantially above slow asynchronous control rates. The emitter-follower output and short-circuit protection are useful in externally connected equipment. Industrial qualification still depends on the complete system's temperature requirements, surge protection, isolation strategy, and regulatory compliance rather than the line-driver IC alone.
Inirekomenda
Test and Measurement Interfaces
The SN75123D is useful in test and measurement equipment that must stimulate remote receivers over terminated cable runs. Its low-impedance emitter-follower outputs provide stronger drive than conventional logic buffers, while the 3.11 V output at -59.3 mA specification supports a defined high-level load. The maximum transmit delay of 25 ns provides useful timing margin for moderate-speed control or measurement buses. Instrument designers should account for cable attenuation, connector reflections, receiver loading, and the difference between logical command speed and the rise time of the physical transmission line.
Inirekomenda
Buod ng mga Inirekomendang Produkto
Impormasyon ng Talumpati sa Engineering for SN75123D — ikabit, gabay sa disenyo, at impormasyon ng pagsunod sa kautusan.
Paunawang Hanapin
Ikabit sa Mga Alternatibo
| Parametro | Ito ang Producto |
|---|---|
| Product Type | Dual line driver |
| Number of Channels | 2 |
| Supply Voltage | 5 V |
| Maximum Supply Voltage | 5.25 V |
| Output Voltage | 3.11 V at -59.3 mA |
| Maximum Transmit Delay | 25 ns |
| Maximum Supply Current | 60 mA |
| Logic Compatibility | Standard TTL |
| Output Structure | Uncommitted emitter-follower |
| Package | 16-pin SOIC |
| Brand | Texas Instruments |
Talaan ng Disenyo
Do not enable two SN75123D outputs simultaneously when they connect to the same party-line conductor with opposite output states. The uncommitted emitter-follower architecture permits shared-bus use only when output-enable sequencing keeps inactive drivers at high impedance. Review every connected driver and receiver in the complete bus, not just the local transmitter.
Treat the external line as a transmission-line problem when distance, data rate, or connector transitions are significant. Characteristic-impedance matching, source or load termination, stub length, and connector reflections determine whether the 3.11 V output at -59.3 mA and 25 ns maximum transmit delay produce a usable receiver waveform. Validate the assembled cable and termination network with suitable measurement equipment.
Route each driver output directly toward its connector or termination network, and keep the return-current path continuous beneath or adjacent to the signal trace. Place local supply bypassing at the device and maintain a low-impedance ground reference. Separate the two line-driver channels when they carry unrelated or high-slew-rate signals to minimize crosstalk.
Design the 5 V rail for the stated 60 mA maximum supply current plus the load presented by the receiving interface and associated circuitry. Decoupling should follow the manufacturer datasheet recommendations, and the supply must remain within the 5.25 V maximum. Verify startup and fault behavior at the board level rather than assuming the nominal 5 V rail is always sufficient.
Impormasyon ng Pagsunod sa Kautusan
No explicit compliance declarations are identified in the manufacturer product-page summary or distributor results. Confirm RoHS, REACH, lead-free, halogen-free, and conflict-minerals status from the current manufacturer documentation or applicable material declarations before procurement.