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Home > Products > Integrated Circuits (ICs) > Logic > Signal Switches, Multiplexers, Decoders

Renesas QS3VH251QG8

Name: QS3VH251QG8
Brand: Renesas
SKU: QS3VH251QG8
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: QS3VH251QG8

Manufacturer:: Renesas

Category:: Signal Switches, Multiplexers, Decoders

Package:: 16-SSOP (0.154", 3.90mm Width)

Datasheet:: QS3VH251QG8.pdf

Description:: IC BUS SWITCH 1 X 8:1 16QSOP

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Product details

Overview

QS3VH251QG8 from Renesas Electronics (formerly IDT) is a quad 8:1 analog multiplexer/demultiplexer bus switch with rail-to-rail switching (0–5 V), 4 Ω typical ON resistance, <0.2 ns propagation delay, and 500 MHz bandwidth. It operates from 2.3 V to 3.6 V V_CC, supports hot-swapping, and is rated for –40°C to +85°C industrial temperature range.

For engineers reviewing the QS3VH251QG8 datasheet, QS3VH251QG8 pinout, QS3VH251QG8 application, or QS3VH251QG8 equivalent, key selection criteria include 5 V-tolerant I/Os in both ON/OFF states, LVTTL-compatible control inputs, bidirectional zero-delay signal routing, and QSOP-20 green package compatibility with high-density PCB layouts.

Technical Context

The QS3VH251QG8 implements four independent 8:1 analog MUX/DEMUX channels using N-channel FET switches without parasitic diodes to V_CC, enabling true isolation during power-off and eliminating DC paths to supply or ground. Each channel features matched R_ON (±0.5 Ω typical variation) and flat R_ON vs. input voltage profile across the full 0–5 V range.

Control logic uses active-low Enable (E) and three-bit binary Select (S2:S0) per channel, with LVTTL-compatible thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V at V_CC = 2.7–3.6 V). Switching is fully bidirectional, with identical t_PLH/t_PHL ≤ 0.2 ns and disable/enable times ≤ 9 ns under industrial conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CC Range	2.3 V to 3.6 V - supports dual-supply 2.5 V/3.3 V systems without level shifters
R_ON (Typ.)	4 Ω at V_CC = 3.3 V - enables low-insertion-loss analog/data bus switching
Propagation Delay	<0.2 ns - adds negligible timing skew in high-speed parallel interfaces
Bandwidth	500 MHz - sustains integrity of fast digital edges and analog signals up to ~300 MHz fundamental
I/O Voltage Tolerance	–0.5 V to +5.5 V - allows safe interfacing with 5 V logic or analog sources while powered from 2.5 V/3.3 V
Off-State Leakage	±1 μA max - ensures minimal crosstalk and signal corruption in high-impedance demux paths
Operating Temp	–40°C to +85°C - qualified for industrial control, telecom line cards, and embedded computing

Pinout & Package

QS3VH251QG8 is housed in a 20-pin QSOP (Green) package (JEDEC MO-137AC), 7.2 mm × 4.4 mm footprint, 0.65 mm pitch. Pin 10 is NC; pins 9 and 11 are GND and V_CC, respectively.

Pin/Terminal	Circuit Role	Design Meaning
I0–I7	Data Input (per channel)	Eight bidirectional analog/digital inputs per MUX; tolerate 0–5 V regardless of V_CC
Y	Data Output (per channel)	Single bidirectional output per channel; matches Ix impedance and timing characteristics
S0–S2	Select Input	3-bit binary address selecting one of eight Ix inputs to connect to Y; LVTTL-compatible
E	Enable Input	Active-low global enable; disables all four channels simultaneously into high-Z state
V_CC	Supply Terminal	Power for control logic and gate drive; no current path to I/O when off
GND	Ground Reference	Common return for control and signal paths; decoupling required near pin 9

Key Features

Feature	Design Value
N-channel FET architecture	No parasitic body diode to V_CC - prevents back-powering and enables true power-off isolation
Rail-to-rail analog switching	0 V to 5 V signal range supported - eliminates clipping in mixed-voltage data acquisition paths
5 V-tolerant I/Os	Operates safely with 5 V signals while V_CC = 2.5 V/3.3 V - removes need for external level translators
Low and flat R_ON	4 Ω typical, ±0.5 Ω matching across channels - ensures uniform gain/attenuation in multi-channel mux applications
Undershoot clamp diodes	On all switch and control pins - protects against –3 V transient spikes without external components

Applications

Hot-Swappable Backplane Interface	High-Speed Memory Multiplexing
Use Scenario: Replacing failed pluggable modules in live telecom or server backplanes without system shutdown. IC Role / Device Role / Timing Role: Bidirectional signal path selector between midplane and card-edge connectors, enabling zero-downtime insertion/removal. Use Value: 5 V tolerance and power-off isolation prevent bus contention and backfeeding during hot-swap transitions.	Use Scenario: Sharing a single DDR memory controller among multiple memory banks in FPGA-based test equipment. IC Role / Device Role / Timing Role: Quad 8:1 analog MUX routes address/data/control lines between controller and selected bank with sub-0.2 ns added delay. Use Value: Matched R_ON and rail-to-rail operation preserve signal integrity across 200+ MHz memory clocks.
Analog Signal Routing in DAQ Systems	ATM Cell Switching Interface
Use Scenario: Configurable front-end signal conditioning for multi-channel data acquisition with programmable sensor input selection. IC Role / Device Role / Timing Role: Low-distortion analog switch routing sensor outputs to ADC inputs, supporting DC–500 MHz bandwidth. Use Value: 4 pF OFF-state capacitance and 4 Ω R_ON minimize settling time and crosstalk between high-impedance sensor channels.	Use Scenario: Interfacing ATM SAR controllers to physical layer transceivers in legacy 25/155 Mbps switching nodes. IC Role / Device Role / Timing Role: High-bandwidth bus switch handling cell header and payload routing with deterministic latency. Use Value: Sub-0.2 ns propagation delay and 500 MHz bandwidth meet strict jitter budgets for ATM cell timing compliance.

Hot-Swappable Backplane Interface

High-Speed Memory Multiplexing

Use Scenario: Replacing failed pluggable modules in live telecom or server backplanes without system shutdown.

IC Role / Device Role / Timing Role: Bidirectional signal path selector between midplane and card-edge connectors, enabling zero-downtime insertion/removal.

Use Value: 5 V tolerance and power-off isolation prevent bus contention and backfeeding during hot-swap transitions.

Use Scenario: Sharing a single DDR memory controller among multiple memory banks in FPGA-based test equipment.

IC Role / Device Role / Timing Role: Quad 8:1 analog MUX routes address/data/control lines between controller and selected bank with sub-0.2 ns added delay.

Use Value: Matched R_ON and rail-to-rail operation preserve signal integrity across 200+ MHz memory clocks.

Analog Signal Routing in DAQ Systems

ATM Cell Switching Interface

Use Scenario: Configurable front-end signal conditioning for multi-channel data acquisition with programmable sensor input selection.

IC Role / Device Role / Timing Role: Low-distortion analog switch routing sensor outputs to ADC inputs, supporting DC–500 MHz bandwidth.

Use Value: 4 pF OFF-state capacitance and 4 Ω R_ON minimize settling time and crosstalk between high-impedance sensor channels.

Use Scenario: Interfacing ATM SAR controllers to physical layer transceivers in legacy 25/155 Mbps switching nodes.

IC Role / Device Role / Timing Role: High-bandwidth bus switch handling cell header and payload routing with deterministic latency.

Use Value: Sub-0.2 ns propagation delay and 500 MHz bandwidth meet strict jitter budgets for ATM cell timing compliance.

Equivalent & Alternatives

The following parts are listed as comparable options for similar analog multiplexer/demultiplexer applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74CBT16244DGGR	16-bit non-inverting bus switch; no select logic; fixed 1:1 mapping per channel	Lacks MUX/DEMUX functionality; suited only for parallel bus isolation, not channel selection	Choose when replacing mechanical relays in static I/O expansion, not dynamic signal routing
MAX4581ESE+	Single 8:1 CMOS MUX; 3.5 Ω R_ON; 100 MHz bandwidth; requires external level-shifting for 5 V I/O	Lower bandwidth and no 5 V tolerance limit use in >100 MHz digital or mixed-signal paths	Prefer for low-cost, low-frequency analog MUX where 5 V tolerance and 500 MHz are not required

Compared with SN74CBT16244DGGR and MAX4581ESE+, the QS3VH251QG8 uniquely combines quad 8:1 selectability, 500 MHz bandwidth, 5 V I/O tolerance, and power-off isolation-making it irreplaceable in hot-swap-capable, high-speed multiplexing systems requiring deterministic latency and rail-to-rail analog fidelity.

Availability

QS3VH251QG8 is available at Aetrix Electronics and suitable for hot-swappable backplane interfaces, high-speed memory multiplexing, analog signal routing in DAQ systems, and ATM cell switching interfaces requiring stable component supply across industrial temperature ranges.

Supply support for QS3VH251QG8 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

Renesas Electronics Corporation is a global semiconductor leader delivering microcontrollers, analog, power, and connectivity solutions for automotive, industrial, infrastructure, and IoT applications.

The QS3VH251QG8 belongs to Renesas' legacy QuickSwitch® analog bus switch family, originally developed by IDT to address high-bandwidth, low-latency signal routing needs in telecom, computing, and instrumentation systems.

FAQ

What is the maximum signal voltage the QS3VH251QG8 can handle when V_CC = 2.5 V?

The QS3VH251QG8 supports DC signal voltages from –0.5 V to +5.5 V on all I/O pins (I0–I7, Y), regardless of V_CC level. When V_CC = 2.5 V, the device maintains full 5 V tolerance on inputs and outputs, enabling safe interfacing with 5 V logic or analog sources without level translation. This capability is confirmed in the Absolute Maximum Ratings table and reinforced by the "5V tolerant I/Os" feature listing.

Does the QS3VH251QG8 support bidirectional signal flow?

Yes, the QS3VH251QG8 supports fully bidirectional signal flow between Ix and Y terminals with identical electrical characteristics in both directions. Propagation delay (t_PLH/t_PHL ≤ 0.2 ns), ON resistance (4 Ω typical), and capacitance (4 pF OFF, 20–28 pF ON) are symmetric. This is explicitly stated in the datasheet description: "Bidirectional dataflow with near-zero delay" and verified in the Functional Block Diagram and Switching Characteristics tables.

What is the function of the NC pin on the QS3VH251QG8?

Pin 10 of the QS3VH251QG8 is designated NC (No Connect) in the Pin Configuration diagram and has no internal connection. It must remain unconnected on the PCB layout and should not be tied to V_CC, GND, or any other signal. This is confirmed in the top-view QSOP pinout illustration and the "PIN DESCRIPTION" section, which lists only I0–I7, S0–S2, E, Y, V_CC, GND, and NC - with no functional assignment for pin 10.

Can the QS3VH251QG8 be used in power-off isolation scenarios?

Yes, the QS3VH251QG8 provides true power-off isolation due to its N-channel FET architecture with no parasitic diode to V_CC. When V_CC = 0 V, IOFF leakage is ±1 μA max across I/O pins, and the switch remains in high-impedance state. This behavior is documented in the Features list ("Isolation under power-off conditions") and DC Electrical Characteristics table (IOFF parameter), making it suitable for hot-swap and fail-safe system architectures.

What package type does the QS3VH251QG8 use?

The QS3VH251QG8 uses a 20-pin QSOP (Quarter-Size Outline Package) with green RoHS-compliant finish, indicated by the "QG" suffix in the ordering code. Its dimensions are 7.2 mm × 4.4 mm with 0.65 mm lead pitch. This is confirmed in the Ordering Information section and Pin Configuration diagram, which specifies "QSOP – Green" for QG and shows the 20-pin top view layout.

QS3VH251QG8 Specifications

Product attributes: Attribute value

Manufacturer:: Renesas

Series:: 3VH

Package/Case:: 16-SSOP (0.154", 3.90mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Bus Switch

Circuit:: 1 x 8:1

Independent Circuits:: 1

Current - Output High, Low:: -

Voltage Supply Source:: Single Supply

Voltage - Supply:: 2.3V ~ 3.6V

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 16-QSOP

QS3VH251QG8 FAQ

1.How can I place an order for QS3VH251QG8 through Aetrix?

Please submit a Request for Quotation (RFQ) for QS3VH251QG8 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 QS3VH251QG8 reliable?

The price and inventory of QS3VH251QG8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for QS3VH251QG8 is usually 5 days.

3.What payment methods are accepted for QS3VH251QG8?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for QS3VH251QG8 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for QS3VH251QG8?

QS3VH251QG8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your QS3VH251QG8 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 QS3VH251QG8?

For technical support, including QS3VH251QG8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your QS3VH251QG8 requirements.

6.How does Aetrix verify that QS3VH251QG8 is sourced from the original manufacturer or authorized distributors?

All QS3VH251QG8 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 QS3VH251QG8 meets industry standards.

7.What is the process for return or replacement of QS3VH251QG8?

All QS3VH251QG8 units undergo pre-shipment inspection (PSI). If there is an issue with QS3VH251QG8, 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 QS3VH251QG8 part is unused and in its original packaging.

Return procedure for QS3VH251QG8:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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