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onsemi DM74LS125AN
- Part No.:
- DM74LS125AN
- Manufacturer:
- onsemi
- Package:
- 14-DIP (0.300", 7.62mm)
- Datasheet:
-
DM74LS125AN.pdf
- Description:
- IC BUF NON-INVERT 5.25V 14DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,624
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Product details
Overview
DM74LS125AN from Fairchild Semiconductor is a quad non-inverting 3-STATE buffer IC in 14-lead PDIP package, operating at 4.75–5.25 V supply, with 24 mA low-level output drive, 2.4 V minimum VOH at IOH = −2.6 mA, and 0.35 V maximum VOL at IOL = 24 mA - used for bidirectional bus interfacing in TTL-based digital systems.
For engineers reviewing the DM74LS125AN datasheet, pinout, applications, or equivalent options, key selection factors include guaranteed 3-STATE disable timing (tPLZ/tPHZ ≤ 20 ns), bus-compatible output drive without pull-ups, and operation across 0°C to +70°C industrial temperature range.
Technical Context
This device implements four independent TTL-compatible buffer gates, each with separate active-low enable control (C input) and non-inverting data path (A → Y). The 3-STATE outputs are fully compatible with LS-TTL logic families and designed for direct connection to shared data buses.
Enable/disable asymmetry is intentional: disable time (tPLZ, tPHZ) is specified ≤20 ns, while enable time (tPZH, tPZL) is up to 40 ns - minimizing bus contention risk when multiple buffers share a line.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.75 V to 5.25 V - ensures compatibility with standard 5 V TTL power rails and noise margin stability |
| IOL / IOH | 24 mA / −2.6 mA - supports direct driving of multiple LS-TTL inputs (fan-out ≥20) without external termination |
| VOL / VOH | 0.35 V max / 2.4 V min at rated load - meets LS-TTL output voltage thresholds for reliable logic level recognition |
| tPLH / tPHL | 15–22 ns - enables synchronous operation in 20–25 MHz bus cycles with controlled propagation skew |
| tPLZ / tPHZ | ≤20 ns - guarantees fast high-impedance transition to prevent bus conflicts during multi-driver arbitration |
| Operating Temp | 0°C to +70°C - qualified for commercial and industrial ambient environments without derating |
Pinout & Package
DM74LS125AN is housed in a 14-lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" wide, with through-hole mounting and standard 0.1" pin pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 4, 10, 13 | Output (Y1–Y4) | 3-STATE buffered outputs - present low-impedance logic levels when enabled, high-Z when disabled |
| 2, 5, 9, 12 | Data Input (A1–A4) | Non-inverting input per channel - passes logic state directly to corresponding output when enabled |
| 3, 6, 8, 11 | Enable Input (C1–C4) | Active-low enable control - Y = A when C = L; Y = Hi-Z when C = H |
| 7 | GND | Ground reference for all internal circuitry and output drivers |
| 14 | VCC | +5 V supply rail - powers all four buffer channels and 3-STATE output stages |
Key Features
| Feature | Design Value |
|---|---|
| Quad independent 3-STATE buffers | Enables four isolated data paths on one IC - reduces board space vs discrete buffers and simplifies bus arbitration logic |
| Faster disable than enable timing | tPLZ/tPHZ ≤ 20 ns vs tPZH/tPZL up to 40 ns - prevents bus contention during switching between drivers |
| LS-TTL compatible drive strength | 24 mA sink / 2.6 mA source - eliminates need for external pull-up resistors on shared bus lines |
| Guaranteed bus-safe output states | IOZL/IOZH ≤ ±20 µA in Hi-Z - presents negligible loading to bus during disable, avoiding signal corruption |
Applications
| Microprocessor Bus Interface | Memory Address Latching |
|---|---|
Use Scenario: Isolating CPU address/data bus from peripheral logic during DMA or interrupt cycles. IC Role / Device Role / Timing Role: DM74LS125AN acts as a controlled bidirectional bus driver, enabling/disabling data flow per channel under control signal timing. Use Value: Eliminates bus contention by ensuring only one driver is active at a time, leveraging fast 20 ns disable time to meet tight arbitration windows. | Use Scenario: Driving multiplexed address lines to static RAM or ROM chips in 8-bit microcontroller systems. IC Role / Device Role / Timing Role: DM74LS125AN buffers and isolates address signals from MCU port pins, preventing loading-induced timing skew. Use Value: Maintains clean TTL logic levels across 10+ cm PCB traces due to 24 mA drive capability and low VOL (0.35 V). |
| Logic Level Translation | Test Equipment Signal Gating |
Use Scenario: Interfacing legacy 5 V TTL logic with newer low-voltage peripherals requiring clean enable-controlled signal pass-through. IC Role / Device Role / Timing Role: DM74LS125AN serves as a voltage-level-consistent, enable-gated buffer - no level shifting, but precise TTL-compatible signal conditioning. Use Value: Provides deterministic Hi-Z isolation between domains, avoiding leakage paths that could corrupt test setup states. | Use Scenario: Enabling/disabling stimulus signals in automated test fixtures based on controller-generated strobes. IC Role / Device Role / Timing Role: DM74LS125AN functions as a precision gating element - output reflects input only when enable is asserted, with sub-25 ns enable delay. Use Value: Guarantees signal integrity during transient switching via controlled rise/fall and minimal off-state current (≤20 µA). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad 3-STATE buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LS125N | Identical electrical specs, same PDIP-14 package, TI-manufactured with identical pinout and timing | No functional difference - drop-in replacement in legacy TTL designs | Select SN74LS125N if sourcing from TI-distributed channels or requiring TI-specific traceability |
| MC74LS125PG | Onsemi version; same VCC, IOL, VOL, and timing specs; also PDIP-14, pin-compatible | Same bus interface use cases; minor variation in ICC (11–20 mA vs 12–19 mA) - no design impact | Choose MC74LS125PG where Onsemi supply chain alignment or long-term availability is prioritized |
Compared with DM74LS125AN, SN74LS125N offers identical performance and footprint with TI branding, while MC74LS125PG provides equivalent functionality with Onsemi's manufacturing continuity - both require no schematic or layout changes.
Availability
DM74LS125AN is available at Aetrix Electronics and suitable for microprocessor bus interface, memory address latching, and logic-level gating applications requiring stable component supply and long-lifecycle support.
Supply support for DM74LS125AN includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Fairchild Semiconductor was a leading designer of analog and mixed-signal ICs, acquired by ON Semiconductor in 2016; its legacy TTL logic portfolio remains widely deployed in industrial and legacy systems.
The DM74LS125A series was developed to provide robust, pin-compatible 3-STATE buffering for TTL-based bus architectures - emphasizing bus contention avoidance, predictable timing, and industrial temperature reliability.
FAQ
What is the function of the C input on DM74LS125AN?
The C input on DM74LS125AN is an active-low enable control for each buffer channel. When C = LOW, the corresponding Y output follows the A input (Y = A); when C = HIGH, the Y output enters high-impedance (Hi-Z) state. This allows dynamic bus sharing without contention - critical for DM74LS125AN integration into multi-driver systems.
Does DM74LS125AN support 3.3 V operation?
No, DM74LS125AN is specified only for 4.75–5.25 V operation and is not 3.3 V tolerant. Its input thresholds (VIL = 0.8 V, VIH = 2.0 V) and output drive characteristics are optimized for 5 V TTL logic. Using DM74LS125AN with 3.3 V supplies may result in undefined behavior or damage due to VIH/VIL mismatch and insufficient noise margins.
What is the maximum capacitive load DM74LS125AN can drive reliably?
DM74LS125AN is characterized for CL = 50 pF and CL = 150 pF in switching specifications, with propagation delays increasing predictably (e.g., tPLH from 15 ns to 21 ns). It can reliably drive up to 150 pF loads while maintaining timing compliance - sufficient for typical PCB traces and 10–15 LS-TTL inputs. Exceeding this requires verification of setup/hold margins in the target DM74LS125AN application.
Is DM74LS125AN RoHS compliant?
Original DM74LS125AN devices were manufactured prior to RoHS enforcement and are leaded (Pb) PDIP packages. Modern re-manufactured or drop-in replacements (e.g., SN74LS125N, MC74LS125PG) offer RoHS-compliant versions. For new designs requiring compliance, verify the specific date code and packaging notation - DM74LS125AN itself is not RoHS certified.
How does DM74LS125AN differ from DM74LS126AN?
DM74LS125AN features active-low enable (C) and non-inverting output (Y = A), whereas DM74LS126AN has active-high enable and inverting output (Y = NOT A). Their pinouts are identical, but logic behavior differs fundamentally - DM74LS125AN cannot substitute for DM74LS126AN without redesigning enable polarity and signal inversion in the system using DM74LS125AN.
DM74LS125AN Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- 74LS
- Package/Case:
- 14-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Logic Type:
- Buffer, Non-Inverting
- Number of Elements:
- 4
- Number of Bits per Element:
- 1
- Input Type:
- -
- Output Type:
- 3-State
- Current - Output High, Low:
- 2.6mA, 24mA
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 14-MDIP
DM74LS125AN FAQ
1.How can I place an order for DM74LS125AN through Aetrix?
Please submit a Request for Quotation (RFQ) for DM74LS125AN on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for DM74LS125AN reliable?
The price and inventory of DM74LS125AN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DM74LS125AN is usually 5 days.
3.What payment methods are accepted for DM74LS125AN?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DM74LS125AN transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DM74LS125AN?
DM74LS125AN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DM74LS125AN order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for DM74LS125AN?
For technical support, including DM74LS125AN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DM74LS125AN requirements.
6.How does Aetrix verify that DM74LS125AN is sourced from the original manufacturer or authorized distributors?
All DM74LS125AN products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that DM74LS125AN meets industry standards.
7.What is the process for return or replacement of DM74LS125AN?
All DM74LS125AN units undergo pre-shipment inspection (PSI). If there is an issue with DM74LS125AN, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The DM74LS125AN part is unused and in its original packaging.
Return procedure for DM74LS125AN:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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