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Texas Instruments SN74HC138QPWRG4Q1
- Part No.:
- SN74HC138QPWRG4Q1
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
SN74HC138QPWRG4Q1.pdf
- Description:
- IC DECODER/DEMUX 1X3:8 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:566
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Product details
Overview
SN74HC138QPWRG4Q1 from Texas Instruments is an automotive-qualified 3-line-to-8-line decoder/demultiplexer in a 16-pin TSSOP package, operating from 2 V to 6 V, with typical propagation delay of 15 ns at 6 V, ±4-mA output drive at 5 V, and low ICC of 80 µA max - used for memory decoding and data routing in engine control units and ADAS sensor interfaces.
For engineers reviewing the SN74HC138QPWRG4Q1 datasheet, SN74HC138QPWRG4Q1 pinout, SN74HC138QPWRG4Q1 application, or SN74HC138QPWRG4Q1 equivalent, key selection criteria include automotive temperature range (−40°C to 125°C), three enable inputs for cascading, active-low outputs, and TSSOP-16 footprint compatibility with space-constrained automotive PCBs.
Technical Context
This device implements combinational logic decoding using CMOS technology with two active-low (G2A, G2B) and one active-high (G1) enable inputs, allowing flexible cascading without external inverters - e.g., a 24-line decoder requires no additional logic, while a 32-line implementation needs only one inverter. Its binary-select inputs (A, B, C) determine which of eight outputs (Y0–Y7) is asserted low.
Designed specifically for high-speed memory systems, the SN74HC138QPWRG4Q1 minimizes system decoding delay: its tpd (≤46 ns at 6 V) and fast-enable memory timing typically fall below memory access time, making decoder-induced latency negligible. Output drive capability supports up to 10 LSTTL loads, ensuring robust signal integrity across noisy automotive bus environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2 V to 6 V - supports wide-input rail operation across 3.3 V and 5 V automotive subsystems. |
| Propagation Delay (tpd) | 15 ns typical at 6 V - enables synchronization with high-speed memory enable signals in ECU designs. |
| Output Drive | ±4 mA at 5 V - sufficient to directly interface with TTL loads or drive small-signal logic without buffering. |
| ICC (Max) | 80 µA - ensures ultra-low quiescent power in always-on vehicle modules like body controllers. |
| Operating Temperature | −40°C to 125°C - qualified per AEC-Q100 for under-hood and safety-critical automotive applications. |
| ESD Rating | >2000 V HBM, >200 V MM - meets automotive board-level ESD immunity requirements without added protection. |
| Input Current (II) | 1 µA max - prevents loading of upstream logic in battery-sensitive wake-up circuits. |
Pinout & Package
TSSOP-16 package (PW), 4.4 mm × 5.0 mm footprint, 1.2 mm max height, lead pitch 0.65 mm, RoHS-compliant NIPDAU finish, MSL Level-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (G2A) | Active-low enable input | Asserted low to activate decoding; used with G2B and G1 for hierarchical enable control. |
| 2 (G2B) | Active-low enable input | Second active-low enable; both G2A and G2B must be low for device to respond to selects. |
| 3 (G1) | Active-high enable input | Asserted high to enable; allows mixed-polarity enable logic for simplified cascading. |
| 4 (C) | MSB address input | Most significant bit of 3-bit binary select; determines Y4–Y7 vs. Y0–Y3 activation group. |
| 5 (B) | Mid-bit address input | Second bit of address; combined with A and C to uniquely select one of eight outputs. |
| 6 (A) | LSB address input | Least significant bit; full 3-bit decode yields single active-low output among Y0–Y7. |
| 7 (Y0) | Active-low decoded output | Asserted low when A=B=C=0 and all enables active; drives downstream enable or chip-select lines. |
| 8 (GND) | Ground reference | Power return path; must be low-impedance to maintain noise margin in automotive harness environments. |
| 9 (Y1) | Active-low decoded output | Asserted low when A=1, B=C=0; used for discrete peripheral selection in multi-sensor clusters. |
| 10 (Y2) | Active-low decoded output | Asserted low when B=1, A=C=0; supports modular I/O expansion in gateway ECUs. |
| 11 (Y3) | Active-low decoded output | Asserted low when A=B=1, C=0; enables selective activation of CAN transceiver banks. |
| 12 (Y4) | Active-low decoded output | Asserted low when C=1, A=B=0; routes clock or reset signals to specific domain controllers. |
| 13 (Y5) | Active-low decoded output | Asserted low when A=1, C=1, B=0; isolates diagnostic communication paths during firmware updates. |
| 14 (Y6) | Active-low decoded output | Asserted low when B=1, C=1, A=0; controls power sequencing of camera ISP modules. |
| 15 (Y7) | Active-low decoded output | Asserted low when A=B=C=1; triggers safety shutdown in redundant sensor fusion units. |
| 16 (VCC) | Supply voltage | 2–6 V digital supply; decoupling capacitor required near pin to suppress switching noise in 12 V vehicle systems. |
Key Features
| Feature | Design Value |
|---|---|
| Three enable inputs (G1, G2A, G2B) | Enables seamless 3-to-24 or 3-to-32 line expansion without external inverters - reduces BOM count and layout area. |
| Automotive qualification (AEC-Q100) | Validated for −40°C to 125°C operation and ESD robustness - eliminates requalification effort for Tier 1 suppliers. |
| Low ICC (80 µA max) | Minimizes standby current in always-on domains such as vehicle intrusion detection or telematics wake logic. |
| 15 ns typical tpd at 6 V | Ensures timing closure in high-speed memory decode paths where access time budgets are sub-50 ns. |
| ±4-mA drive at 5 V | Directly drives LSTTL inputs or small MOSFET gates - avoids level-shifter or buffer ICs in cost-sensitive modules. |
| Input transition time support down to 400 ns | Accommodates slower edge rates from microcontroller GPIOs or legacy ASICs without timing violation. |
Applications
| Engine Control Unit (ECU) Memory Decoding | ADAS Sensor Multiplexing |
|---|---|
|
Use Scenario: Selecting between multiple flash memory banks or SRAM modules in a dual-core powertrain controller. IC Role / Device Role / Timing Role: 3-to-8 line decoder providing chip-select signals synchronized to CPU address bus cycles. Use Value: Propagation delay ≤46 ns ensures no penalty on memory access timing; automotive temp rating guarantees reliability under hood thermal cycling. |
Use Scenario: Routing CAN, LIN, or SPI signals from a central MCU to eight radar, camera, or ultrasonic sensor nodes. IC Role / Device Role / Timing Role: Demultiplexer enabling time-shared communication with distributed sensors via enable-controlled output gating. Use Value: Three enable inputs allow hierarchical arbitration - e.g., G1 from safety core, G2A/G2B from application core - enforcing fail-safe isolation. |
| Body Control Module (BCM) I/O Expansion | Infotainment System Peripheral Selection |
|
Use Scenario: Expanding GPIO count to manage 24+ lighting zones, door locks, and HVAC actuators using cascaded SN74HC138QPWRG4Q1 devices. IC Role / Device Role / Timing Role: Cascadable decoder generating discrete enable signals for driver ICs or optocouplers. Use Value: No external inverters needed for 24-line expansion - reduces component count, PCB layers, and failure points in Class A interiors. |
Use Scenario: Selecting between audio codecs, display drivers, Bluetooth/Wi-Fi modules, and USB PHYs in a head-unit SoC design. IC Role / Device Role / Timing Role: Address-decoded peripheral selector asserting chip-select lines based on AXI or APB bus address bits. Use Value: Low 1 µA input current prevents loading of SoC address lines; TSSOP-16 footprint fits tight routing channels near BGA packages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 3-to-8 decoder/demultiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HC138QPWRQ1 | Same silicon, identical electrical specs, but MSL Level-3 (vs. Level-1 for SN74HC138QPWRG4Q1) and different tape-and-reel packaging. | No functional difference; suitable for same automotive applications but requires moisture-sensitive handling pre-reflow. | Select SN74HC138QPWRG4Q1 for standard SMT lines without dry-pack logistics; choose SN74HC138QPWRQ1 only if existing process already manages Level-3 MSL flow. |
| SN74HCS138QPWRG4Q1 | Includes Schmitt-trigger inputs for improved noise immunity; otherwise identical pinout, timing, and drive strength. | Better suited for noisy under-dash or chassis-mounted locations where slow-rising or noisy address signals occur. | Choose SN74HCS138QPWRG4Q1 when interfacing with unfiltered microcontroller outputs or long traces; retain SN74HC138QPWRG4Q1 for clean, short-board routed systems. |
Compared with SN74HC138QPWRQ1, SN74HC138QPWRG4Q1 offers simpler handling (MSL Level-1), while SN74HCS138QPWRG4Q1 adds Schmitt-trigger inputs for marginal signal integrity - neither is pin-compatible with non-HC-family decoders like CD74HC238, which lacks automotive qualification and has different enable logic.
Availability
SN74HC138QPWRG4Q1 is available at Aetrix Electronics and suitable for engine control units, ADAS sensor hubs, and body control modules requiring stable component supply across automotive production lifecycles.
Supply support for SN74HC138QPWRG4Q1 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 specializing in analog, embedded processing, and automotive-grade logic solutions with over 50 years of automotive component validation experience.
The SN74HC138QPWRG4Q1 belongs to TI's automotive HC logic family, engineered for high-speed, low-power decoding in safety-critical vehicle subsystems where timing predictability and environmental resilience are mandatory.
FAQ
What is the maximum operating temperature for SN74HC138QPWRG4Q1?
The SN74HC138QPWRG4Q1 is rated for continuous operation from −40°C to 125°C ambient temperature, meeting AEC-Q100 Grade 1 requirements for under-hood and powertrain applications. This specification is validated per TI's automotive qualification protocol and confirmed in the SCLS533A datasheet revision September 2008.
Does SN74HC138QPWRG4Q1 support 3.3 V logic levels?
Yes, SN74HC138QPWRG4Q1 operates across 2 V to 6 V VCC, including 3.3 V nominal rails. At VCC = 3.3 V, VIH is 2.31 V min and VIL is 1.09 V max per recommended operating conditions, ensuring reliable interfacing with 3.3 V microcontrollers and FPGAs without level translation.
Can SN74HC138QPWRG4Q1 be used as a demultiplexer?
Yes, SN74HC138QPWRG4Q1 functions as a 1-to-8 demultiplexer when one enable input (e.g., G1) is used as the data input and A, B, C serve as select lines - producing inverted data on the selected Yx output. This mode is explicitly supported in the functional description and timing diagrams of the SN74HC138QPWRG4Q1 datasheet.
What is the pin pitch and package outline for SN74HC138QPWRG4Q1?
SN74HC138QPWRG4Q1 uses the TSSOP-16 (PW) package with 0.65 mm lead pitch, 4.4 mm × 5.0 mm body dimensions, and 1.2 mm maximum height. The official package drawing PW0016A defines land pattern, stencil design, and solder mask openings - all available in TI's Package Materials Information document dated 24-Jul-2025.
Is SN74HC138QPWRG4Q1 pin-compatible with SN74HC138QPWRQ1?
Yes, SN74HC138QPWRG4Q1 and SN74HC138QPWRQ1 share identical pinout, electrical specifications, and functionality - differing only in moisture sensitivity level (MSL Level-1 vs. Level-3) and tape-and-reel packaging details. Both use the same TSSOP-16 (PW) footprint and can be substituted on the same PCB layout without modification.
SN74HC138QPWRG4Q1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74HC
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Decoder/Demultiplexer
- Circuit:
- 1 x 3:8
- Independent Circuits:
- 1
- Current - Output High, Low:
- 5.2mA, 5.2mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 2V ~ 6V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP
SN74HC138QPWRG4Q1 FAQ
1.How can I place an order for SN74HC138QPWRG4Q1 through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74HC138QPWRG4Q1 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 SN74HC138QPWRG4Q1 reliable?
The price and inventory of SN74HC138QPWRG4Q1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74HC138QPWRG4Q1 is usually 5 days.
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Once your SN74HC138QPWRG4Q1 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 SN74HC138QPWRG4Q1?
For technical support, including SN74HC138QPWRG4Q1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74HC138QPWRG4Q1 requirements.
6.How does Aetrix verify that SN74HC138QPWRG4Q1 is sourced from the original manufacturer or authorized distributors?
All SN74HC138QPWRG4Q1 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 SN74HC138QPWRG4Q1 meets industry standards.
7.What is the process for return or replacement of SN74HC138QPWRG4Q1?
All SN74HC138QPWRG4Q1 units undergo pre-shipment inspection (PSI). If there is an issue with SN74HC138QPWRG4Q1, 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 SN74HC138QPWRG4Q1 part is unused and in its original packaging.
Return procedure for SN74HC138QPWRG4Q1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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