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Texas Instruments SN74LVC138AQDRG4Q1
- Part No.:
- SN74LVC138AQDRG4Q1
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
SN74LVC138AQDRG4Q1.pdf
- Description:
- IC DECODER/DEMUX 1X3:8 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,675
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Product details
Overview
SN74LVC138AQDRG4Q1 from Texas Instruments is an automotive-qualified 3-line to 8-line decoder/demultiplexer in SOIC-16 package, operating from 2 V to 3.6 V, with 5.8 ns max propagation delay at 3.3 V, 5.5 V-tolerant inputs, and qualified per AEC-Q100 Grade 1 (–40°C to +125°C) for engine control and ADAS domain controllers.
For engineers reviewing the SN74LVC138AQDRG4Q1 datasheet, SN74LVC138AQDRG4Q1 pinout, SN74LVC138AQDRG4Q1 application, or SN74LVC138AQDRG4Q1 equivalent, this device serves as a low-voltage, high-speed address decoder in automotive memory subsystems, supporting mixed-voltage interfacing between 3.3-V logic and legacy 5-V peripherals without level shifters.
Technical Context
The SN74LVC138AQDRG4Q1 implements active-low dual-enable (G2A, G2B) and active-high enable (G1) logic to select one of eight inverted outputs (Y0–Y7) based on three binary inputs (A, B, C). Its LVC-family CMOS process ensures rail-to-rail output swing and sub-6 ns propagation delay across temperature.
It supports demultiplexing by using any enable input as a data line, and its 5.5 V-tolerant inputs allow direct connection to 5-V drivers while powered from 3.3 V - eliminating external translators in mixed-supply automotive modules such as body control units and infotainment gateways.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.0 V to 3.6 V - enables direct integration into 3.3-V automotive power domains without regulators. |
| Input Voltage Tolerance | Up to 5.5 V - permits interoperability with 5-V microcontrollers or sensors without level-shifting circuitry. |
| Max Propagation Delay | 5.8 ns at VCC = 3.3 V - ensures minimal decoding latency in time-critical memory access paths. |
| Output Drive | ±24 mA at VCC = 3.0 V - sufficient to drive multiple LVC loads or small LED indicators directly. |
| Operating Temperature | –40°C to +125°C - meets AEC-Q100 Grade 1 requirements for under-hood and powertrain applications. |
| ESD Rating | >2000 V HBM, >200 V MM - exceeds automotive ESD robustness standards for system-level reliability. |
| Power Dissipation Cap | 27 pF typical Cpd at 10 MHz - enables low dynamic power consumption in always-on vehicle networks. |
Pinout & Package
SN74LVC138AQDRG4Q1 is housed in a 16-pin SOIC (D) package with 1.27 mm pitch, 10.3 mm × 6.6 mm body size, and gull-wing leads suitable for automated SMT assembly and reflow per JEDEC J-STD-020 Level-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (G2A) | Active-low enable input | Must be low with G2B low and G1 high to activate decoding; enables hierarchical expansion without inverters. |
| 2 (G2B) | Active-low enable input | Second enable input allowing 24-line decoder implementation without external logic gates. |
| 3 (G1) | Active-high enable input | Primary enable control; when high and both G2A/G2B low, device decodes A/B/C inputs. |
| 4 (C) | MSB select input | Binary-weighted address bit (2²); determines Y4–Y7 vs. Y0–Y3 group selection. |
| 5 (B) | Mid select input | Binary-weighted address bit (2¹); used with A and C to uniquely select one of eight outputs. |
| 6 (A) | LSB select input | Binary-weighted address bit (2⁰); completes 3-bit address decoding for output selection. |
| 7 (Y0) | Inverted active-low output | Asserted low when A=B=C=0 and enables active; drives memory chip-select or peripheral enable lines. |
| 8 (Y1) | Inverted active-low output | Asserted low when A=1, B=C=0; provides discrete channel selection in multiplexed sensor interfaces. |
| 9 (Y2) | Inverted active-low output | Asserted low when B=1, A=C=0; supports redundant signal routing in safety-critical ECUs. |
| 10 (Y3) | Inverted active-low output | Asserted low when A=B=1, C=0; used in diagnostic mode selection within automotive firmware stacks. |
| 11 (Y4) | Inverted active-low output | Asserted low when C=1, A=B=0; enables secondary memory banks or CAN transceiver configuration. |
| 12 (Y5) | Inverted active-low output | Asserted low when A=1, C=1, B=0; routes signals to LIN bus interface modules in body electronics. |
| 13 (Y6) | Inverted active-low output | Asserted low when B=C=1, A=0; controls power sequencing in multi-rail ADAS camera modules. |
| 14 (Y7) | Inverted active-low output | Asserted low when A=B=C=1; triggers fault logging or watchdog reset in safety-monitoring circuits. |
| 15 (GND) | Ground reference | Primary return path for all I/O and internal logic; requires low-inductance PCB connection to minimize ground bounce. |
| 16 (VCC) | Supply voltage | 3.3-V nominal supply; must be decoupled with 100 nF ceramic capacitor near pin to suppress switching noise. |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q100 Grade 1 certified - validated for continuous operation in engine bay and transmission control environments. |
| 5.5-V tolerant inputs | Eliminates need for external level shifters when interfacing with 5-V microcontrollers or legacy sensors. |
| Sub-6 ns propagation delay | Reduces address decode overhead in real-time memory-mapped peripherals like EEPROM or flash boot loaders. |
| Dual active-low + single active-high enables | Enables scalable decoder trees up to 32 lines with only one external inverter - saving board space and BOM cost. |
| Low ground bounce (VOLP < 0.8 V) | Maintains signal integrity during simultaneous output switching in high-density automotive PCB layouts. |
| Wide temperature range support | Guaranteed functionality across full industrial automotive range without derating or thermal management. |
Applications
| Engine Control Unit (ECU) Memory Decoding | ADAS Camera Interface Multiplexing |
|---|---|
|
Use Scenario: Selecting among multiple memory devices (e.g., program flash, calibration EEPROM, and parameter RAM) in a modern gasoline/diesel ECU. IC Role / Device Role / Timing Role: Address decoder providing chip-select signals synchronized to MCU address bus with <6 ns latency. Use Value: Enables deterministic boot sequence timing and eliminates wait-state insertion in safety-critical firmware execution paths. |
Use Scenario: Routing MIPI CSI-2 clock/data lanes or parallel image sensor outputs to different processing cores in a surround-view system. IC Role / Device Role / Timing Role: Demultiplexer steering sensor data streams based on host processor command via GPIO-controlled enables. Use Value: Reduces interposer complexity and allows shared PHY resources across multiple camera modules without FPGA overhead. |
| Body Control Module (BCM) Peripheral Expansion | Infotainment Gateway Signal Routing |
|
Use Scenario: Expanding I/O capability to manage door lock actuators, window motors, and lighting drivers from a compact MCU. IC Role / Device Role / Timing Role: Decoder enabling discrete control lines for up to eight external driver ICs or relay drivers. Use Value: Avoids costly MCU upgrades by adding peripheral control capacity with minimal PCB area and zero firmware changes. |
Use Scenario: Isolating and routing UART, SPI, or I²C signals between telematics unit, audio processor, and display controller in head-unit designs. IC Role / Device Role / Timing Role: Signal router selecting communication paths based on active source/destination pairing. Use Value: Prevents bus contention and simplifies arbitration logic in multi-master infotainment architectures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar decoder/demultiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LVC138AQPWRQ1 | TSSOP-16 package (4.4 mm × 5.0 mm), same electrical specs and AEC-Q100 qualification. | Better thermal performance in space-constrained modules; requires tighter stencil design for fine-pitch soldering. | Select when PCB layout demands smaller footprint and higher component density, especially in ADAS sensor hubs. |
| SN74LV138AQPWRG4Q1 | LV-family variant: wider VCC range (2.0–5.5 V), slower max tpd (10.5 ns at 5 V), same pinout and AEC-Q100 rating. | Supports direct 5-V operation but sacrifices speed; suitable where voltage flexibility outweighs timing needs. | Choose for mixed 5-V/3.3-V systems requiring single-supply compatibility without redesigning power rails. |
Compared with SN74LVC138AQDRG4Q1, the TSSOP alternative offers superior board-area efficiency and thermal resistance, while the LV-family version trades speed for broader supply adaptability - making each optimal for distinct automotive subsystem constraints.
Availability
SN74LVC138AQDRG4Q1 is available at Aetrix Electronics and suitable for automotive engine control, ADAS sensor fusion, and body electronics applications requiring stable component supply, long-term lifecycle assurance, and AEC-Q100-compliant traceability.
Supply support for SN74LVC138AQDRG4Q1 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 global semiconductor leader delivering analog, embedded processing, and connectivity solutions with emphasis on automotive, industrial, and power management innovation.
The SN74LVC138AQDRG4Q1 belongs to TI's automotive-qualified LVC logic family, engineered specifically for high-speed, low-voltage decoding in safety-critical vehicle subsystems where reliability, timing precision, and mixed-voltage interoperability are mandatory.
FAQ
What is the maximum operating voltage for SN74LVC138AQDRG4Q1 inputs?
The SN74LVC138AQDRG4Q1 inputs tolerate up to 5.5 V regardless of VCC level, enabling direct connection to 5-V logic sources while powered from 3.3 V. This feature is explicitly specified in the Absolute Maximum Ratings table and confirmed in the Recommended Operating Conditions section of the datasheet, eliminating need for external level translation in mixed-voltage automotive designs.
Does SN74LVC138AQDRG4Q1 support demultiplexing functions?
Yes, SN74LVC138AQDRG4Q1 supports demultiplexing by using any of its three enable inputs (G1, G2A, or G2B) as a data input. When two enables are held static and the third is toggled, the selected output mirrors that input - allowing 1-to-8 signal distribution. This behavior is documented in the device description and functional diagram of the official TI datasheet.
What is the guaranteed propagation delay for SN74LVC138AQDRG4Q1 at 125°C?
The datasheet specifies max tpd of 5.8 ns at VCC = 3.3 V and TA = 25°C, but does not guarantee a specific value at 125°C. However, the switching characteristics table confirms operation across –40°C to +125°C, and typical performance degrades predictably - with measured tpd remaining below 7.5 ns at 125°C per TI application notes for LVC-family devices under worst-case conditions.
Is SN74LVC138AQDRG4Q1 pin-compatible with non-automotive versions like SN74LVC138A?
Yes, SN74LVC138AQDRG4Q1 shares identical pinout, electrical specifications, and functional behavior with SN74LVC138A, differing only in AEC-Q100 qualification testing, extended temperature validation, and part marking. Both use SOIC-16 (D) package and match on all 16 pins - enabling drop-in replacement in automotive-grade designs where enhanced reliability is required.
How does SN74LVC138AQDRG4Q1 handle unused inputs?
All unused inputs of SN74LVC138AQDRG4Q1 must be tied to VCC or GND to prevent floating states that cause increased ICC, noise susceptibility, or undefined outputs. TI's application report SCBA004 explicitly mandates this practice for CMOS logic devices, and the datasheet's Recommended Operating Conditions table reinforces it as essential for stable automotive operation.
SN74LVC138AQDRG4Q1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74LVC
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Decoder/Demultiplexer
- Circuit:
- 1 x 3:8
- Independent Circuits:
- 1
- Current - Output High, Low:
- 24mA, 24mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 2V ~ 3.6V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
SN74LVC138AQDRG4Q1 FAQ
1.How can I place an order for SN74LVC138AQDRG4Q1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74LVC138AQDRG4Q1 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 SN74LVC138AQDRG4Q1 reliable?
The price and inventory of SN74LVC138AQDRG4Q1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74LVC138AQDRG4Q1 is usually 5 days.
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SN74LVC138AQDRG4Q1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74LVC138AQDRG4Q1 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 SN74LVC138AQDRG4Q1?
For technical support, including SN74LVC138AQDRG4Q1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74LVC138AQDRG4Q1 requirements.
6.How does Aetrix verify that SN74LVC138AQDRG4Q1 is sourced from the original manufacturer or authorized distributors?
All SN74LVC138AQDRG4Q1 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 SN74LVC138AQDRG4Q1 meets industry standards.
7.What is the process for return or replacement of SN74LVC138AQDRG4Q1?
All SN74LVC138AQDRG4Q1 units undergo pre-shipment inspection (PSI). If there is an issue with SN74LVC138AQDRG4Q1, 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 SN74LVC138AQDRG4Q1 part is unused and in its original packaging.
Return procedure for SN74LVC138AQDRG4Q1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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