My Inquiry
My Account
Texas Instruments SN74LS379N
- Part No.:
- SN74LS379N
- Manufacturer:
- Texas Instruments
- Category:
- Flip Flops
- Package:
- -
- Datasheet:
-
SN74LS379N.pdf
- Description:
- BIPOLAR GP LOGIC SCHOTTKY
- Quantity:
- Payment:
- Shipping:
Inventory:1,766
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74LS379N from Texas Instruments is a quad D-type flip-flop with individual enable control per pair, implemented in bipolar TTL technology, operating at 0°C to 70°C, featuring 16-pin PDIP packaging, 15 ns typical propagation delay (tPLH/tPHL), and compatible with standard LS logic voltage levels (VCC = 5 V). It serves as a synchronous data latch in address/data bus buffering and state register applications within legacy industrial controllers.
For engineers reviewing the SN74LS379N datasheet, SN74LS379N pinout, SN74LS379N application, or SN74LS379N equivalent, key selection considerations include its dual-pair independent enable architecture, guaranteed fan-out of 20 LS-TTL loads, DC noise margin of 0.4 V (min), and compatibility with 74LS-series timing and drive requirements in retrofitted or maintenance-replacement designs.
Technical Context
The SN74LS379N integrates four edge-triggered D-type flip-flops grouped into two independent pairs (Q0–Q1 and Q2–Q3), each with dedicated active-low enable inputs (1EN̅ and 2EN̅) that gate clock signals to their respective pair-enabling selective latching without global clock gating. Its internal structure uses Schottky-clamped bipolar transistors to achieve stable switching at 30 MHz maximum clock frequency under specified load conditions.
It operates strictly as a positive-edge-triggered device with setup time (tSU) of 20 ns and hold time (tH) of 0 ns relative to the clock, and exhibits output drive capability of –0.4 mA (IOH) and 8 mA (IOL) at VCC = 5 V, ensuring robust interfacing with other 74LS-family components in mixed-logic subsystems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | 74LS (Low-power Schottky TTL) - ensures interoperability with legacy 74LS systems and predictable DC/AC loading behavior. |
| Function | Quad D-type flip-flop with dual independent enables - supports two isolated 2-bit latched data paths in one package. |
| Propagation Delay | 15 ns max (tPLH/tPHL at VCC = 5 V, CL = 15 pF) - defines maximum clock-to-output timing for synchronous design timing closure. |
| Supply Voltage | 4.75 V to 5.25 V - requires regulated 5 V rail; operation outside this range risks metastability or output invalidity. |
| Operating Temperature | 0°C to +70°C - rated for commercial-grade environments only; not suitable for extended industrial or automotive ambient ranges. |
| Fan-out | 20 LS-TTL loads - determines how many downstream 74LS inputs can be driven directly without buffering. |
| Output Drive | IOL = 8 mA / IOH = –0.4 mA - specifies sink/source current capability for driving LEDs, small relays, or logic inputs under worst-case conditions. |
Pinout & Package
SN74LS379N is supplied in a 16-pin plastic dual in-line package (PDIP-N), 0.3-inch body width, with standard through-hole mounting and JEDEC MS-001 compliant footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | 1EN̅ | Active-low enable for first flip-flop pair (Q0/Q1); when high, clocks to Q0/Q1 are blocked regardless of CLK state. |
| 2 | D0 | Data input for first flip-flop (Q0); sampled on rising CLK edge if 1EN̅ = low. |
| 3 | CLK | Common clock input for all four flip-flops; positive-edge triggered; shared across both pairs. |
| 4 | Q0 | True output of first flip-flop; reflects D0 state after next qualifying CLK edge. |
| 5 | Q0̅ | Complementary output of first flip-flop; always inverse of Q0; no additional delay beyond Q0. |
| 6 | D1 | Data input for second flip-flop in first pair (Q1); sampled synchronously with D0 on same CLK edge. |
| 7 | Q1 | True output of second flip-flop in first pair; latched copy of D1 aligned with Q0 timing. |
| 8 | GND | Ground reference for all internal circuitry and output drivers; must be low-impedance connection. |
| 9 | Q1̅ | Complementary output of Q1; provides inverted data path without external inverter. |
| 10 | 2EN̅ | Active-low enable for second pair (Q2/Q3); independent of 1EN̅, enabling asymmetric latching control. |
| 11 | D2 | Data input for third flip-flop (Q2); enabled only when 2EN̅ = low and CLK rises. |
| 12 | Q2 | True output of third flip-flop; synchronized to CLK but gated by 2EN̅, decoupling from first pair. |
| 13 | Q2̅ | Inverted output of Q2; electrically matched to Q2 for differential signaling or logic inversion. |
| 14 | D3 | Data input for fourth flip-flop (Q3); shares CLK and 2EN̅ with Q2, forming second 2-bit latch group. |
| 15 | Q3 | True output of fourth flip-flop; completes quad latch function with precise timing alignment to Q2. |
| 16 | VCC | +5 V power supply; must be bypassed locally with 0.1 µF ceramic capacitor to GND for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent enable control | Allows selective latching of two 2-bit data groups using separate 1EN̅ and 2EN̅ signals-eliminates need for external gating logic. |
| Positive-edge clock triggering | Ensures deterministic sampling at rising CLK transitions, simplifying timing analysis in synchronous bus architectures. |
| Complementary outputs per flip-flop | Provides Q and Q̅ on every stage, enabling direct connection to differential receivers or static logic without inverters. |
| LS-TTL compatible voltage thresholds | Guarantees interoperability with existing 74LS systems: VIL ≤ 0.8 V, VIH ≥ 2.0 V, eliminating level-shifting requirements. |
| 16-pin PDIP package | Supports through-hole prototyping and legacy PCB replacement; pin-compatible with socketed 74LS373/374 footprints in many layouts. |
Applications
| Industrial PLC I/O Expansion | Legacy Microprocessor Address Latching |
|---|---|
Use Scenario: Expanding discrete I/O points in aging programmable logic controllers where space and board real estate limit component count. IC Role / Device Role / Timing Role: SN74LS379N acts as a dual 2-bit address/data latch, capturing parallel sensor status or actuator command bits under microcontroller control. Use Value: Reduces required IC count by 50% versus using two SN74LS374s, lowering BOM cost and PCB routing complexity in retrofit upgrades. | Use Scenario: Stabilizing 8-bit address bus segments in Z80- or 8085-based embedded systems during memory-mapped peripheral access. IC Role / Device Role / Timing Role: SN74LS379N latches lower-address nibbles (A0–A3) and control strobes (IORQ̅, RD̅) with independent enables for timing isolation. Use Value: Enables clean separation of address setup and data sampling windows via 1EN̅/2EN̅, preventing bus contention during multi-cycle instructions. |
| Test Equipment Digital Pattern Storage | Electromechanical Control Sequencing |
Use Scenario: Capturing and holding digital test vectors in automated test fixtures for discrete component validation. IC Role / Device Role / Timing Role: SN74LS379N stores four independent test stimulus bits synchronized to pattern generator clock edges. Use Value: Complementary outputs allow direct drive of both normally open and normally closed relay coils without added inverters. | Use Scenario: Implementing step-indexed sequencing logic for stepper motor drivers or pneumatic valve banks in factory automation panels. IC Role / Device Role / Timing Role: SN74LS379N holds current sequence state bits (e.g., Step 1–4) and enables transition to next state on clock pulse. Use Value: Dual-enable architecture permits pausing one axis while advancing another-critical for coordinated multi-axis motion control. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad D-type flip-flop applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LS374N | Octal D-type with single enable and 3-state outputs; no complementary outputs; 20-pin PDIP. | Designed for bus-oriented bidirectional data flow; lacks per-pair enable and Q̅ outputs needed for dual-latch isolation. | Select SN74LS374N only when 3-state bus driving is required and layout allows 20-pin footprint. |
| SN74LS175N | Quad D-type with common clear (CLR̅), no individual enables, and no complementary outputs; 16-pin PDIP. | Requires external gating for selective latching; CLR̅ resets all outputs simultaneously-unsuitable for partial state retention. | Choose SN74LS175N only for simple reset-dominant applications where enable granularity is unnecessary. |
Compared with SN74LS379N, SN74LS374N offers higher density (8 bits vs. 4) but sacrifices independent enable control and complementary outputs, while SN74LS175N retains the 16-pin form factor but removes the critical dual-enable feature-making SN74LS379N uniquely suited for asymmetric, isolated 2-bit latching tasks.
Availability
SN74LS379N is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy microprocessor address latching, and electromechanical control sequencing requiring stable component supply and long-term obsolescence mitigation.
Supply support for SN74LS379N 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
Texas Instruments is a U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic products with broad industrial and aerospace heritage.
The SN74LS379N belongs to TI's legacy 74LS logic family, engineered specifically for reliability and interoperability in commercial-grade digital control systems deployed from the 1970s through early 2000s.
FAQ
What is the maximum clock frequency supported by the SN74LS379N?
The SN74LS379N supports a maximum clock frequency of 30 MHz under standard test conditions (VCC = 5 V, TA = 25°C, CL = 15 pF). This rating assumes proper enable signal timing and load compliance; actual usable frequency in system-level designs may be lower due to trace capacitance, fan-out, and temperature derating. The SN74LS379N datasheet specifies tPLH/tPHL ≤ 15 ns, which sets the fundamental timing limit for reliable edge registration.
Does the SN74LS379N have asynchronous reset or preset functionality?
No, the SN74LS379N does not include asynchronous reset (CLR̅) or preset (PRE̅) inputs. It is a purely synchronous D-type flip-flop relying solely on the rising edge of CLK and the state of 1EN̅/2EN̅ for data capture. Any reset functionality must be implemented externally-for example, by forcing D inputs low and pulsing CLK while enabling the relevant pair. This distinguishes the SN74LS379N from variants like SN74LS175N, which includes a shared CLR̅ input.
Can the SN74LS379N be used as a replacement for SN74LS374 in an existing design?
The SN74LS379N cannot serve as a drop-in replacement for SN74LS374 due to fundamental functional and pinout differences: SN74LS374 is octal with 3-state outputs and a single enable, while SN74LS379N is quad with complementary outputs and dual enables. Pin assignments are incompatible (16-pin vs. 20-pin), and electrical behavior differs-especially regarding output drive mode and enable logic polarity. Direct substitution would require PCB redesign and firmware logic revision.
What is the purpose of the complementary outputs (Q̅) on each flip-flop in the SN74LS379N?
The complementary outputs (Q0̅, Q1̅, Q2̅, Q3̅) on the SN74LS379N provide logically inverted copies of each true output, enabling direct interface with differential receivers, NAND/NOR-based combinational logic, or dual-coil electromechanical actuators without external inverters. This reduces component count and propagation delay in timing-critical paths-for instance, driving both SET and RESET inputs of an RS latch or controlling complementary transistor switches in power stages.
Is the SN74LS379N RoHS-compliant?
Yes, the SN74LS379N is RoHS-compliant, as confirmed by Texas Instruments' packaging documentation: it features NiPdAu (NIPDAU) lead finish and meets EU Directive 2011/65/EU requirements. The "Yes" RoHS designation appears in TI's official package addendum for orderable part number SN74LS379N, with MSL rating marked as "N/A for Pkg Type" due to its PDIP construction. No lead (Pb) is present in the finished device.
SN74LS379N Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Function:
- -
- Type:
- -
- Output Type:
- -
- Number of Elements:
- -
- Number of Bits per Element:
- -
- Clock Frequency:
- -
- Max Propagation Delay @ V, Max CL:
- -
- Trigger Type:
- -
- Current - Output High, Low:
- -
- Voltage - Supply:
- -
- Current - Quiescent (Iq):
- -
- Input Capacitance:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
SN74LS379N FAQ
1.How can I place an order for SN74LS379N through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74LS379N 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 SN74LS379N reliable?
The price and inventory of SN74LS379N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74LS379N is usually 5 days.
3.What payment methods are accepted for SN74LS379N?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74LS379N transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74LS379N?
SN74LS379N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74LS379N 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 SN74LS379N?
For technical support, including SN74LS379N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74LS379N requirements.
6.How does Aetrix verify that SN74LS379N is sourced from the original manufacturer or authorized distributors?
All SN74LS379N 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 SN74LS379N meets industry standards.
7.What is the process for return or replacement of SN74LS379N?
All SN74LS379N units undergo pre-shipment inspection (PSI). If there is an issue with SN74LS379N, 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 SN74LS379N part is unused and in its original packaging.
Return procedure for SN74LS379N:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74LS379N Tags
-
SN74HC74DR
Texas Instruments
-
SN74HC74PWR
Texas Instruments
-
74LVC1G74GT,115
Nexperia USA Inc.
-
SN74LVC2G74DCUR
Texas Instruments
-
CD4013BM96
Texas Instruments
-
SN74HCT273PWR
Texas Instruments
-
SN74LVC1G74DCUR
Texas Instruments
-
SN74HC574DWR
Texas Instruments
-
74LVC1G74DC,125
Nexperia USA Inc.
-
SN74HC273DWR
Texas Instruments
-
SN74HCT574DWR
Texas Instruments
-
SN74LVC1G74DCTR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
