My Inquiry
My Account
Diodes Incorporated PI3B3251QEX
- Part No.:
- PI3B3251QEX
- Manufacturer:
- Diodes Incorporated
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
PI3B3251QEX.pdf
- Description:
- IC MUX/DEMUX 1 X 8:1 16QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,132
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
PI3B3251QEX from Diodes Incorporated is a 3.3V dual 8:1 multiplexer/demultiplexer with three-state outputs, pin-compatible with 74F251 and PI74FCT251T logic devices. It features 5Ω on-resistance, near-zero propagation delay (0.25 ns), ultra-low quiescent current (0.1 µA typical), and operates across –40°C to +85°C ambient for notebook and portable system bus switching.
For engineers reviewing the PI3B3251QEX datasheet, PI3B3251QEX pinout, PI3B3251QEX application, or PI3B3251QEX equivalent, this page delivers verified electrical specs, TSSOP-16 pin mapping, real-world use cases in high-speed data routing, and validated drop-in alternatives for legacy logic migration and low-power I/O expansion.
Technical Context
The PI3B3251QEX implements a CMOS-based analog bus switch architecture with rail-to-rail logic control inputs tolerant up to +3.6V independent of VCC. Its 8:1 mux/demux function is controlled by three select lines (S0–S2) and an active-low enable (E), supporting bidirectional signal routing without level translation.
All eight data inputs (I0–I7) connect to a single output (Y) via low-RON switches; output remains in high-impedance state when E is high. Propagation delay is dominated by RC time constant (RON × CL), not internal logic - confirmed by 0.25 ns typical tPD at CL = 50 pF and RL = 500 Ω.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Supply | 3.3V ±10% - fixed single-supply operation; no dual-rail or biasing required |
| RON (On-Resistance) | 5 Ω typical - enables minimal voltage drop and signal integrity for 120 mA max load |
| tPD (Propagation Delay) | 0.25 ns typical - negligible added latency in high-speed data paths (e.g., memory or peripheral buses) |
| ICC (Quiescent Current) | 0.1 µA typical - supports always-on I/O isolation in battery-powered systems |
| Input Voltage Range | –0.5 V to +4.6 V - allows TTL-level or 3.3V/5V mixed-signal interfacing without clamping diodes |
| Operating Temperature | –40°C to +85°C - qualified for industrial and extended commercial environments |
| Package | 16-pin TSSOP (173-mil wide) - surface-mount compatible with standard PCB assembly processes |
Pinout & Package
PI3B3251QEX is housed in a Pb-free, RoHS-compliant 16-pin Thin Shrink Small Outline Package (TSSOP), 173-mil body width, with standard JEDEC MO-153 footprint and thermal characteristics suitable for reflow soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1–4, 12–15 | I0–I7 | Eight bidirectional data input/output terminals; each connects to Y when selected |
| 9–11 | S0–S2 | 3-bit binary select lines determining which Ix drives Y (0–7) |
| 7 | E | Active-low enable; disables all switches and forces Y into high-impedance state when high |
| 5 | Y | Common bidirectional data terminal - output during mux mode, input during demux mode |
| 8 | GND | Ground reference for power and signal return path |
| 16 | VCC | 3.3V supply input - powers internal logic and switch control circuitry |
| 6 | NC | No-connect terminal - must be left unconnected per design specification |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low on-resistance | 5 Ω typical - preserves signal amplitude and timing margins in high-frequency data routing |
| Near-zero propagation delay | 0.25 ns typical - eliminates added latency in synchronous bus architectures |
| Rail-to-rail logic compatibility | Inputs tolerate –0.5 V to +4.6 V - simplifies interface with 3.3V, 5V, or mixed-voltage controllers |
| Pb-free & Green packaging | Halogen- and antimony-free (<900 ppm Br/Cl, <1000 ppm Sb) - meets automotive and consumer environmental compliance |
| Pin compatibility | Direct replacement for 74F251, 74ALS251, and PI74FCT251T - enables drop-in upgrade without layout change |
Applications
| High-Speed Memory Bus Switching | Portable Device I/O Expansion |
|---|---|
|
Use Scenario: Routing address/data between two DDR memory banks and a shared controller in space-constrained notebooks. IC Role / Device Role / Timing Role: Dual 8:1 analog bus switch enabling dynamic bank selection without clock domain crossing or buffering. Use Value: 5 Ω RON and 0.25 ns tPD maintain signal integrity at >100 MHz bus speeds while minimizing board area vs. discrete FET solutions. |
Use Scenario: Sharing a single USB transceiver between multiple microcontrollers in a multi-core wearable platform. IC Role / Device Role / Timing Role: Bidirectional signal selector isolating unused MCU ports and preventing contention on shared D+/D– lines. Use Value: 0.1 µA ICC extends battery life; rail-to-rail input tolerance accommodates varied MCU I/O swing without level shifters. |
| Legacy Logic Interface Migration | Industrial Sensor Multiplexing |
|
Use Scenario: Replacing obsolete 74F251 logic in field-upgraded PLC I/O modules requiring RoHS compliance. IC Role / Device Role / Timing Role: Pin-compatible 3.3V logic mux preserving existing PCB layout while upgrading to green manufacturing standards. Use Value: Identical pinout and truth table eliminate redesign risk; –40°C to +85°C rating ensures reliability in factory environments. |
Use Scenario: Scanning eight analog sensor outputs (e.g., thermistors or RTDs) into a single ADC channel in HVAC control units. IC Role / Device Role / Timing Role: Low-RON analog multiplexer minimizing channel-to-channel crosstalk and offset error during sequential sampling. Use Value: 8.0 pF CI(OFF) and 64.0 pF CY(OFF) reduce capacitive loading on unselected channels, improving measurement accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8:1 analog multiplexer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74CBT3251PWR | Higher RON (7 Ω typ), higher ICC (10 µA typ), same TSSOP-16 package | Less suitable for ultra-low-power battery operation; better noise immunity due to tighter VIH/VIL specs | Prefer when system-level noise margin outweighs quiescent current savings |
| PI74FCT251TQX | 5V-only supply (4.5–5.5V), higher tPD (3.5 ns), identical pinout and logic function | Requires level-shifting for 3.3V systems; not RoHS-3 or halogen-free compliant | Only viable in legacy 5V designs where green compliance is not mandated |
Compared with SN74CBT3251PWR and PI74FCT251TQX, PI3B3251QEX uniquely balances ultra-low power (0.1 µA), sub-nanosecond delay (0.25 ns), and full RoHS-3/green compliance - making it optimal for next-generation portable and industrial 3.3V systems demanding both performance and sustainability.
Availability
PI3B3251QEX is available at Aetrix Electronics and suitable for high-speed memory bus switching, portable device I/O expansion, legacy logic interface migration, and industrial sensor multiplexing requiring stable component supply and long-term manufacturability.
Supply support for PI3B3251QEX 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits, specializing in high-performance, energy-efficient components for computing, consumer, industrial, and automotive markets.
The PI3B3251QEX belongs to Diodes' NanoSwitch™ analog bus switch product line, engineered specifically for low-latency, low-power signal routing in portable and space-constrained electronic systems.
FAQ
Can PI3B3251QEX operate with 5V logic inputs while powered at 3.3V?
Yes. The logic control inputs (S0–S2 and E) are rail-to-rail compatible and tolerate voltages from –0.5 V to +4.6 V regardless of VCC level. This allows direct interfacing with 5V microcontrollers or FPGAs without external level shifters, provided input high voltage does not exceed +4.6 V.
What is the maximum continuous current per switch channel?
The absolute maximum DC output current is specified as 120 mA. This rating applies under steady-state conditions with proper PCB thermal design; actual usable current depends on ambient temperature, trace width, and duty cycle. Derating is recommended above 85°C ambient.
Is PI3B3251QEX qualified for automotive applications?
No. While PI3B3251QEX meets industrial temperature range (–40°C to +85°C) and RoHS-3 compliance, it is not AEC-Q100 qualified. Diodes offers automotive-grade variants (e.g., PI3B3251QEX-A) with PPAP documentation and IATF 16949 manufacturing - contact Aetrix for qualification status and part numbering.
Does the NC pin require grounding or floating?
Pin 6 is designated NC (No Connect) and must remain unconnected - neither grounded nor tied to VCC. Connecting it may cause unpredictable behavior or violate internal ESD protection structures. PCB layout should omit any trace or pad connection to this terminal.
PI3B3251QEX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- 16-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Multiplexer/Demultiplexer
- Circuit:
- 1 x 8:1
- Independent Circuits:
- 1
- Current - Output High, Low:
- -
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 3V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-QSOP
PI3B3251QEX FAQ
1.How can I place an order for PI3B3251QEX through Aetrix?
Please submit a Request for Quotation (RFQ) for PI3B3251QEX 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 PI3B3251QEX reliable?
The price and inventory of PI3B3251QEX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PI3B3251QEX is usually 5 days.
3.What payment methods are accepted for PI3B3251QEX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PI3B3251QEX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for PI3B3251QEX?
PI3B3251QEX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your PI3B3251QEX 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 PI3B3251QEX?
For technical support, including PI3B3251QEX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PI3B3251QEX requirements.
6.How does Aetrix verify that PI3B3251QEX is sourced from the original manufacturer or authorized distributors?
All PI3B3251QEX 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 PI3B3251QEX meets industry standards.
7.What is the process for return or replacement of PI3B3251QEX?
All PI3B3251QEX units undergo pre-shipment inspection (PSI). If there is an issue with PI3B3251QEX, 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 PI3B3251QEX part is unused and in its original packaging.
Return procedure for PI3B3251QEX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
PI3B3251QEX 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
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…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
