My Inquiry
My Account
Texas Instruments SN74LVC138APW
- Part No.:
- SN74LVC138APW
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
SN74LVC138APW.pdf
- Description:
- IC DECODER/DEMUX 1X3:8 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,209
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74LVC138APW from Texas Instruments is a 3-line to 8-line decoder/demultiplexer IC operating from 1.65 V to 3.6 V, with inputs tolerant up to 5.5 V, propagation delay as low as 5.8 ns at 3.3 V, and active-low dual enable plus active-high enable architecture. It drives LED matrix column selection in embedded display systems.
For engineers reviewing the SN74LVC138APW datasheet, SN74LVC138APW pinout, SN74LVC138APW application, or SN74LVC138APW equivalent, key selection criteria include supply voltage range (1.65–3.6 V), input overvoltage tolerance (5.5 V), output drive capability (±24 mA), propagation delay (5.8 ns @ 3.3 V), and TSSOP-16 package compatibility with high-density PCB layouts.
Technical Context
The SN74LVC138APW implements combinational logic decoding using three binary select inputs (A, B, C) to activate exactly one of eight active-low outputs (Y0–Y7), while two active-low enables (G2A, G2B) and one active-high enable (G1) collectively gate all outputs. All outputs remain HIGH unless all three enables are simultaneously asserted.
Its CMOS design supports mixed-voltage interfacing: inputs accept 5-V logic levels while operating from a 1.65–3.6-V VCC rail, enabling direct connection to legacy 5-V controllers without level shifters. Output switching is rail-to-rail, with VOL ≤ 0.55 V and VOH ≥ VCC – 0.2 V under rated load conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 1.65 V to 3.6 V - Enables operation in modern low-voltage microcontroller I/O domains while maintaining backward compatibility with 3.3-V systems. |
| Input Voltage Range | 0 V to 5.5 V - Allows direct interface with 5-V TTL or CMOS logic without external level translation circuitry. |
| Propagation Delay | 5.8 ns max at 3.3 V - Supports high-speed address decoding in memory subsystems and real-time LED scanning applications. |
| Output Drive | ±24 mA at 3.0 V - Sufficient to directly sink LED column current in multiplexed displays without external drivers. |
| Enable Logic | G1 (active-high), G2A/G2B (active-low) - Enables hierarchical decoding expansion (e.g., 24-line decoder without inverters) and flexible demultiplexing control. |
| Operating Temperature | –40°C to +85°C - Qualified for industrial-grade embedded applications including factory automation and building controls. |
| ESD Rating | 2000 V HBM - Meets JEDEC JS-001 requirements for robust handling in standard manufacturing environments. |
Pinout & Package
TSSOP-16 (PW) package: 5.00 mm × 4.40 mm body, 0.65 mm lead pitch, exposed pad optional, RoHS-compliant NiPdAu finish, MSL Level-1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (G2A) | Active-low enable A | Must be LOW to enable decoding; used with G2B and G1 to form 3-input AND gate for output activation. |
| 2 (G2B) | Active-low enable B | Second active-low enable; both G2A and G2B must be LOW alongside G1 HIGH for functional output. |
| 3 (G1) | Active-high enable | Primary enable control; when HIGH and G2A/G2B LOW, device decodes A/B/C inputs to Y0–Y7. |
| 4 (C) | Select input C (MSB) | Most significant bit of 3-bit binary address; determines higher-order output group (Y4–Y7 vs Y0–Y3). |
| 5 (B) | Select input B | Mid-significance bit; combined with A and C, fully defines which single output (Y0–Y7) goes LOW. |
| 6 (A) | Select input A (LSB) | Least significant bit; final bit resolving output selection within each 2-output pair. |
| 7 (Y7) | Active-low output 7 | Only output asserted LOW when A=1, B=1, C=1 and all enables active; others remain HIGH. |
| 8 (GND) | Ground reference | Return path for all internal logic and output currents; requires low-impedance PCB plane connection. |
| 9 (Y6) | Active-low output 6 | Asserted LOW only for A=0, B=1, C=1 - used for dedicated peripheral addressing or LED column drive. |
| 10 (Y5) | Active-low output 5 | Decoded output for A=1, B=0, C=1 - supports discrete signal routing in bus arbitration or sensor multiplexing. |
| 11 (Y4) | Active-low output 4 | Activated for A=0, B=0, C=1 - commonly assigned to system reset or watchdog enable lines in embedded designs. |
| 12 (Y3) | Active-low output 3 | Selected when A=1, B=1, C=0 - suitable for interrupt request routing or clock gating control signals. |
| 13 (Y2) | Active-low output 2 | Asserted for A=0, B=1, C=0 - used in memory-mapped I/O decoding for peripheral chip selects. |
| 14 (Y1) | Active-low output 1 | Enabled on A=1, B=0, C=0 - often assigned to UART or SPI peripheral enable in microcontroller expansion. |
| 15 (Y0) | Active-low output 0 | Lowest-address output; asserted when A=0, B=0, C=0 - default boot device select or primary debug interface enable. |
| 16 (VCC) | Power supply | 1.65–3.6 V digital supply; requires local 0.1-µF ceramic bypass capacitor placed adjacent to pin per TI layout guidance. |
Key Features
| Feature | Design Value |
|---|---|
| Wide VCC range | 1.65 V to 3.6 V operation enables use across battery-powered IoT nodes and industrial 3.3-V systems without voltage translation. |
| 5.5-V-tolerant inputs | Eliminates need for external level shifters when interfacing with 5-V microcontrollers, FPGAs, or legacy logic families. |
| Sub-6-ns propagation delay | Ensures minimal timing overhead in high-speed memory decode paths and real-time LED matrix refresh cycles. |
| Three-enable architecture | Supports cascaded decoding (e.g., 24-line) without external inverters, reducing component count and board area. |
| Rail-to-rail CMOS outputs | Delivers full logic swing (VOL ≤ 0.55 V, VOH ≥ VCC – 0.2 V) for reliable noise margin in noisy industrial environments. |
| Industrial temperature range | –40°C to +85°C qualification ensures stable performance in factory automation, power infrastructure, and building controls. |
Applications
| LED Matrix Display Control | Memory Address Decoding |
|---|---|
|
Use Scenario: Driving the column lines of an 8×8 monochrome LED matrix in multiplexed scan mode. IC Role / Device Role / Timing Role: Acts as low-side column selector; each Yx output sinks current for one column while row drivers source current. Use Value: Ensures only one column is active at a time, preventing ghosting and enabling uniform brightness via precise timing control. |
Use Scenario: Selecting among eight peripheral devices (e.g., ADCs, DACs, sensors) mapped to consecutive memory addresses. IC Role / Device Role / Timing Role: Translates upper address bits into individual chip-select signals synchronized with CPU read/write strobes. Use Value: Reduces FPGA or MCU GPIO usage by 5+ pins versus discrete gating; maintains sub-10-ns decode latency for real-time data acquisition. |
| Industrial I/O Expansion | Factory Automation Bus Arbitration |
|
Use Scenario: Expanding digital output capability of a PLC controller to drive 8 solenoid valves or relay coils. IC Role / Device Role / Timing Role: Functions as demultiplexer: G1 accepts serial command data, while A/B/C select target actuator channel. Use Value: Enables single-wire control of multiple actuators with deterministic response time (<6.7 ns) and no software overhead. |
Use Scenario: Managing priority-based access to shared communication resources (e.g., CAN transceiver, RS-485 driver) across 8 subsystems. IC Role / Device Role / Timing Role: Generates mutually exclusive enable signals based on encoded priority bus, preventing bus contention. Use Value: Guarantees hardware-level arbitration with zero-latency decision making, critical for safety-critical motion control loops. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 3-to-8 decoder applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74HC138N | Higher VCC range (2–6 V), slower tpd (21 ns @ 4.5 V), 5-V-only inputs, through-hole DIP-16 package. | Suitable for legacy 5-V systems but incompatible with 1.8-V logic; lacks 5.5-V input tolerance and industrial temp rating. | Choose SN74HC138N only for cost-sensitive, non-portable 5-V designs where speed and mixed-voltage operation are not required. |
| 74LVC138AD | Same electrical specs and logic function, but SOIC-16 (D) package (9.9 mm × 3.91 mm) instead of TSSOP-16 (PW). | SOIC offers easier hand-soldering and rework; TSSOP saves 55% board area and supports finer-pitch routing in space-constrained modules. | Select SN74LVC138AD for prototyping or low-volume assembly; choose SN74LVC138APW for production-grade compact designs requiring automated placement. |
Compared with SN74HC138N, SN74LVC138APW delivers 3.7× faster propagation delay and 5.5-V input tolerance for mixed-voltage systems; versus SN74LVC138AD, it provides identical functionality in a 44% smaller footprint optimized for high-density industrial PCBs.
Availability
SN74LVC138APW is available at Aetrix Electronics and suitable for LED matrix displays, industrial I/O expansion, and memory address decoding requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for SN74LVC138APW 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 logic solutions, with over 50 years of innovation in high-reliability industrial and automotive components.
The SN74LVC138APW belongs to TI's LVC logic family, engineered for low-voltage, high-speed, mixed-signal interfacing in space-constrained industrial and embedded systems where power efficiency and signal integrity are critical.
FAQ
What is the maximum propagation delay of the SN74LVC138APW at 3.3 V?
The maximum propagation delay of the SN74LVC138APW is 5.8 ns when measured from any enable or select input to any output (Y0–Y7) at VCC = 3.3 V ± 0.3 V and TA = 25°C, per TI's SCAS291W datasheet Section 6.7. This value applies to the SN74LVC138APW specifically and confirms its suitability for high-speed address decoding and real-time LED scanning applications.
Can the SN74LVC138APW interface directly with 5-V microcontrollers?
Yes, the SN74LVC138APW accepts input voltages up to 5.5 V regardless of VCC level, allowing direct connection to 5-V microcontrollers without level-shifting circuitry. Its inputs are 5-V tolerant while operating from 1.65–3.6 V, making the SN74LVC138APW ideal for mixed-voltage system integration in industrial control and legacy upgrade scenarios.
What package type does the SN74LVC138APW use?
The SN74LVC138APW uses a TSSOP-16 (PW) package: 5.00 mm × 4.40 mm body size, 0.65 mm lead pitch, with NiPdAu lead finish and Moisture Sensitivity Level 1 (MSL-1). This surface-mount package supports automated assembly and high-density PCB layouts, distinguishing it from SOIC (D) or SSOP (DB) variants of the same logic function.
How does the enable logic work on the SN74LVC138APW?
The SN74LVC138APW features three enable inputs: G1 (active-high), G2A (active-low), and G2B (active-low). All three must be simultaneously asserted - i.e., G1 = HIGH, G2A = LOW, G2B = LOW - for the decoder to operate. If any enable is inactive, all outputs (Y0–Y7) go HIGH. This architecture enables hierarchical expansion and flexible demultiplexing control in the SN74LVC138APW.
Is the SN74LVC138APW suitable for industrial temperature environments?
Yes, the SN74LVC138APW is specified for operation from –40°C to +85°C, meeting industrial temperature requirements. This rating is confirmed in TI's SCAS291W datasheet Section 6.3 (Recommended Operating Conditions) and qualifies the SN74LVC138APW for deployment in factory automation, power infrastructure, and building control systems where ambient thermal stability is essential.
SN74LVC138APW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74LVC
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- 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:
- 1.65V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP
SN74LVC138APW FAQ
1.How can I place an order for SN74LVC138APW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74LVC138APW 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 SN74LVC138APW reliable?
The price and inventory of SN74LVC138APW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74LVC138APW is usually 5 days.
3.What payment methods are accepted for SN74LVC138APW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74LVC138APW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74LVC138APW?
SN74LVC138APW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74LVC138APW 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 SN74LVC138APW?
For technical support, including SN74LVC138APW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74LVC138APW requirements.
6.How does Aetrix verify that SN74LVC138APW is sourced from the original manufacturer or authorized distributors?
All SN74LVC138APW 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 SN74LVC138APW meets industry standards.
7.What is the process for return or replacement of SN74LVC138APW?
All SN74LVC138APW units undergo pre-shipment inspection (PSI). If there is an issue with SN74LVC138APW, 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 SN74LVC138APW part is unused and in its original packaging.
Return procedure for SN74LVC138APW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74LVC138APW Tags
-
SN74HC138DR
Texas Instruments
-
TC7SB3157CFU,LF(CT
Toshiba Semiconductor and Storage
-
74CBTLV3257PW,118
Nexperia USA Inc.
-
SN74CBTLV3257PWR
Texas Instruments
-
74CBTLV3257GUX
Nexperia USA Inc.
-
74HC154BQ,118
Nexperia USA Inc.
-
P3S0200GMX
NXP USA Inc.
-
SN74CB3Q3245PWR
Texas Instruments
-
SN74CB3Q3257RGYR
Texas Instruments
-
TCA9543APWR
Texas Instruments
-
TCA9546APWR
Texas Instruments
-
SN74HC138N
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…
