My Inquiry
My Account
NXP Semiconductors 74HCT138N,652
- Part No.:
- 74HCT138N,652
- Manufacturer:
- NXP Semiconductors
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-DIP (0.300", 7.62mm)
- Datasheet:
-
74HCT138N,652.pdf
- Description:
- IC DECODER/DEMUX 1X3:8 16DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,488
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
74HCT138N,652 from Nexperia is a 3-to-8 line inverting decoder/demultiplexer with TTL-compatible inputs, operating from 4.5 V to 5.5 V supply, featuring three enable inputs (E1, E2 active LOW; E3 active HIGH), eight mutually exclusive active LOW outputs (Y0–Y7), and propagation delay of 20 ns typical at VCC = 4.5 V, CL = 50 pF - used for memory chip select decoding in industrial microcontroller systems.
For engineers reviewing the 74HCT138N,652 datasheet, 74HCT138N,652 pinout, 74HCT138N,652 application, or 74HCT138N,652 equivalent, key selection factors include TTL-level input compatibility, -40 °C to +125 °C operation, SO16 package footprint, inverting output logic, and parallel expansion capability to 1-of-32 decoding.
Technical Context
The 74HCT138N,652 implements combinational logic decoding using standard CMOS transistor architecture with TTL-input threshold levels (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 4.5 V). Its enable structure (E1/E2 LOW + E3 HIGH) provides hierarchical control for cascading multiple devices without external logic.
It delivers active LOW outputs with VOL ≤ 0.26 V at IO = 4.0 mA and VOH ≥ 3.98 V at IO = −4 mA, supporting direct interface to 5 V TTL loads. Input clamp diodes allow safe interfacing to voltages exceeding VCC when used with current-limiting resistors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 4.5 V to 5.5 V - ensures compatibility with standard 5 V TTL logic rails and stable operation across industrial voltage tolerances. |
| Propagation Delay | 20 ns typical (An to Yn, VCC = 4.5 V, CL = 50 pF) - enables reliable timing in address decoding paths up to ~25 MHz system clock domains. |
| Input Thresholds | VIH = 2.0 V min, VIL = 0.8 V max - guarantees robust recognition of standard TTL logic levels without level-shifting circuitry. |
| Output Drive | ±4 mA - sufficient to drive multiple 74-series TTL inputs or small LED indicators directly. |
| Operating Temperature | −40 °C to +125 °C - qualified for extended industrial and under-hood embedded applications without derating. |
| Power Dissipation Capacitance | 67 pF - used to calculate dynamic power (PD = CPD × VCC² × fi × N), critical for thermal budgeting in dense PCB layouts. |
Pinout & Package
74HCT138N,652 is supplied in the SO16 (SOT109-1) plastic small outline package: 16-pin, 3.9 mm body width, 1.27 mm pitch, gull-wing leads, JEDEC MS-012 compliant.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | A0 | LSB address input - selects output Y0/Y1/Y2/Y3 when E1=E2=L, E3=H. |
| 2 | VCC | Positive supply rail - must be decoupled locally with 100 nF ceramic capacitor near pin. |
| 3 | A1 | Middle address input - contributes to binary decode of A2A1A0 (000–111). |
| 4 | E1 | Active LOW enable - all outputs forced HIGH if E1 = HIGH, regardless of other inputs. |
| 5 | E2 | Active LOW enable - second hierarchical control for multi-device expansion. |
| 6 | E3 | Active HIGH enable - required HIGH to activate decoding; enables daisy-chaining with inverters. |
| 7 | Y0 | LSB decoded output (active LOW) - asserted only when A2A1A0 = 000 and enables active. |
| 8 | GND | Ground reference - must connect to low-impedance system ground plane for noise immunity. |
| 9 | Y1 | Second decoded output (active LOW) - asserted only when A2A1A0 = 001. |
| 10 | Y2 | Third decoded output (active LOW) - asserted only when A2A1A0 = 010. |
| 11 | Y3 | Fourth decoded output (active LOW) - asserted only when A2A1A0 = 011. |
| 12 | Y4 | Fifth decoded output (active LOW) - asserted only when A2A1A0 = 100. |
| 13 | Y5 | Sixth decoded output (active LOW) - asserted only when A2A1A0 = 101. |
| 14 | Y6 | Seventh decoded output (active LOW) - asserted only when A2A1A0 = 110. |
| 15 | Y7 | MSB decoded output (active LOW) - asserted only when A2A1A0 = 111. |
| 16 | VCC | Redundant supply pin - electrically identical to pin 2; improves power distribution in high-noise environments. |
Key Features
| Feature | Design Value |
|---|---|
| TTL-compatible inputs | Accepts standard 5 V TTL logic thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V), eliminating need for level shifters in mixed-logic systems. |
| Three enable inputs | E1/E2 (active LOW) + E3 (active HIGH) enable hierarchical decoding and seamless 1-of-32 expansion using four ICs and one inverter. |
| Inverting active LOW outputs | Eight mutually exclusive Y0–Y7 outputs simplify direct connection to active LOW chip select (/CS) inputs of SRAM, EPROM, and peripheral ICs. |
| Clamp diode protection | Internal input clamp diodes permit safe interface to signals exceeding VCC when series current-limiting resistors are used. |
| Industrial temperature range | Specified from −40 °C to +125 °C with full parameter guarantees, supporting deployment in harsh environmental conditions. |
Applications
| Memory Address Decoding | Peripheral Chip Select Logic |
|---|---|
|
Use Scenario: Selecting one of eight memory chips (e.g., SRAM, Flash) in a microcontroller-based data logger with 24-bit address bus. IC Role / Device Role / Timing Role: 3-bit address decoder mapping A0–A2 to eight /CS lines; operates synchronously with CPU address strobe. Use Value: Reduces FPGA or MCU GPIO count by offloading chip select generation, while maintaining sub-25 ns timing margin for 40 MHz bus cycles. |
Use Scenario: Enabling discrete peripherals (ADC, DAC, UART) on an industrial PLC I/O module with shared data bus. IC Role / Device Role / Timing Role: Demultiplexer converting 3-bit peripheral ID into individual /EN signals; E3 used as global enable strobe. Use Value: Eliminates discrete AND-gate networks, cuts BOM cost by 40%, and ensures deterministic 20 ns propagation across all eight channels. |
| LED Segment Driver Enable | Test Equipment Signal Routing |
|
Use Scenario: Driving eight 7-segment LED displays in a factory HMI panel where only one display is active at a time. IC Role / Device Role / Timing Role: Output-enable controller routing common cathode current through Y0–Y7; E1/E2 tied LOW, E3 driven by MCU PWM. Use Value: Enables multiplexed display with uniform brightness control via single E3 duty cycle, avoiding ghosting due to simultaneous activation. |
Use Scenario: Configuring signal paths in automated test equipment (ATE) to route one of eight calibration references to DUT input. IC Role / Device Role / Timing Role: Precision demultiplexer selecting reference voltage source; outputs drive analog switches with <100 ps skew. Use Value: Provides monotonic switching (no glitches) during state transitions, verified by function table truth behavior under all enable combinations. |
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 |
|---|---|---|---|
| 74HC138D,652 | CMOS-input version (VIH = 3.15 V min at VCC = 4.5 V); wider 2.0–6.0 V supply range; 15 ns typical tpd at VCC = 4.5 V. | Requires CMOS-level driving sources; unsuitable for direct TTL bus interfacing without level translation. | Select when system uses mixed 3.3 V/5 V CMOS logic and lower static power (<160 μA ICC max) is prioritized over TTL compatibility. |
| SN74LS138N | Bipolar TTL technology; VIH = 2.0 V min, VIL = 0.8 V max; higher ICC (≈36 mA), slower tpd (≈34 ns), limited to 0 °C to +70 °C. | Higher power draw and narrower temperature range restrict use to commercial-grade boards with ample thermal margin. | Choose only for legacy board refresh where pinout and logic match are mandatory and industrial temp rating is not required. |
Compared with 74HC138D,652, the 74HCT138N,652 offers guaranteed TTL input compatibility at the cost of slightly higher propagation delay; versus SN74LS138N, it delivers 10× lower quiescent current and extended temperature support while retaining identical enable architecture and pinout.
Availability
74HCT138N,652 is available at Aetrix Electronics and suitable for memory address decoding, peripheral chip select logic, LED multiplexing, and test equipment signal routing requiring stable component supply across industrial temperature ranges.
Supply support for 74HCT138N,652 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
Nexperia is a leading semiconductor manufacturer specializing in high-performance logic, analog, and discrete components, with core expertise in automotive-qualified and industrial-grade standard logic families.
The 74HCT138N,652 belongs to Nexperia's 74HCT logic family, engineered specifically for seamless integration between TTL-based legacy systems and modern CMOS microcontrollers in industrial automation and instrumentation.
FAQ
What is the maximum supply voltage rating for the 74HCT138N,652?
The absolute maximum supply voltage (VCC) for the 74HCT138N,652 is +7.0 V, but the recommended operating range is strictly 4.5 V to 5.5 V per datasheet Section 8. Operation above 5.5 V voids parametric guarantees and risks accelerated aging or latch-up under transient conditions. The 74HCT138N,652 must not be operated continuously at 7 V.
Does the 74HCT138N,652 support demultiplexing functionality?
Yes, the 74HCT138N,652 supports demultiplexing: one active LOW enable input (e.g., E1) serves as the data input, while the remaining enables (E2, E3) act as strobes. When E2 = LOW and E3 = HIGH, the data applied to E1 appears inverted on the selected Y output determined by A2–A0. This is explicitly confirmed in Section 1 of the datasheet.
What is the pin 16 function on the 74HCT138N,652 SO16 package?
Pin 16 on the 74HCT138N,652 is a dedicated VCC supply pin - electrically identical to pin 2 (also VCC). This dual-VCC configuration improves power delivery integrity and reduces supply impedance in noise-sensitive applications. Both pins must be connected to the same 4.5–5.5 V rail with local decoupling.
Can the 74HCT138N,652 operate at 3.3 V supply?
No, the 74HCT138N,652 is not specified for 3.3 V operation. Its recommended VCC range is 4.5 V to 5.5 V (Section 8), and TTL input thresholds require minimum 4.5 V to guarantee VIH ≥ 2.0 V and proper noise margins. For 3.3 V systems, use the 74LVC138 or 74AHC138 instead.
Is the 74HCT138N,652 pin-compatible with the 74HC138N?
No - the 74HCT138N,652 and 74HC138N are not pin-compatible because the 74HC138N was discontinued and removed from Nexperia's ordering information as of Revision 5 (2015). Current 74HC138 variants (e.g., 74HC138D) use different packages (SO16, TSSOP16) but share identical pinout and function with 74HCT138N,652 in SO16 form factor.
74HCT138N,652 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- 74HCT
- Package/Case:
- 16-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- Decoder/Demultiplexer
- Circuit:
- 1 x 3:8
- Independent Circuits:
- 1
- Current - Output High, Low:
- 4mA, 4mA
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 16-DIP
74HCT138N,652 FAQ
1.How can I place an order for 74HCT138N,652 through Aetrix?
Please submit a Request for Quotation (RFQ) for 74HCT138N,652 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 74HCT138N,652 reliable?
The price and inventory of 74HCT138N,652 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74HCT138N,652 is usually 5 days.
3.What payment methods are accepted for 74HCT138N,652?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74HCT138N,652 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74HCT138N,652?
74HCT138N,652 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74HCT138N,652 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 74HCT138N,652?
For technical support, including 74HCT138N,652 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74HCT138N,652 requirements.
6.How does Aetrix verify that 74HCT138N,652 is sourced from the original manufacturer or authorized distributors?
All 74HCT138N,652 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 74HCT138N,652 meets industry standards.
7.What is the process for return or replacement of 74HCT138N,652?
All 74HCT138N,652 units undergo pre-shipment inspection (PSI). If there is an issue with 74HCT138N,652, 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 74HCT138N,652 part is unused and in its original packaging.
Return procedure for 74HCT138N,652:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
74HCT138N,652 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…
