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Renesas QS3257S1G8
- Part No.:
- QS3257S1G8
- Manufacturer:
- Renesas
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
QS3257S1G8.pdf
- Description:
- IC MUX/DEMUX 4 X 2:1 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,394
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Product details
Overview
QS3257S1G8 from Renesas Electronics is a high-speed CMOS quad 2:1 multiplexer/demultiplexer with LVTTL-compatible control inputs, 5 Ω typical ON resistance, zero propagation delay, and operation from –40°C to +85°C. It serves as a pin-compatible replacement for 74F257/74FCT257 in logic-level translation, video/audio switching, and hot-swap bus funneling.
For engineers reviewing the QS3257S1G8 datasheet, QS3257S1G8 pinout, QS3257S1G8 application, or QS3257S1G8 equivalent, key selection considerations include bidirectional signal integrity, undershoot clamp diodes on all I/O, TTL-compatible enable/select logic, and industrial-temperature-rated S1 package compatibility with legacy QuickSwitch designs.
Technical Context
The QS3257S1G8 implements four independent bidirectional analog switches controlled by a shared active-low Enable (E) and single Select (S) input. Each switch features enhanced N-channel FETs with no inherent body diode to VCC, enabling true rail-to-rail signal pass without forward conduction.
It supports voltage translation between 5V and 3.3V domains due to its wide DC input voltage range (–0.5 V to +7 V) and guaranteed logic thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V), while maintaining sub-0.25 ns propagation delay contribution under 50 pF load conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| ON Resistance | 5 Ω typical at VCC = 5 V, enabling minimal RC delay and preserving signal edge integrity in high-speed mux paths |
| Propagation Delay Contribution | < 0.25 ns (RC-limited), effectively zero added system delay beyond driver/load interaction |
| Operating Temperature | –40°C to +85°C, qualified for industrial embedded and instrumentation applications |
| Input Voltage Range | –0.5 V to +7 V on all pins except VCC, supporting robust undershoot/overshoot tolerance and level-shifting |
| Control Logic Compatibility | TTL-compatible: VIH ≥ 2.0 V, VIL ≤ 0.8 V, allowing direct interface with legacy 5V logic families |
| Supply Current (Quiescent) | 3 μA max at VCC = 5.25 V, minimizing standby power in always-on signal routing nodes |
Pinout & Package
QS3257S1G8 is housed in a 16-pin Small Outline IC (S1) package - a green, RoHS-compliant variant of SOIC with standard 1.27 mm pitch and 10.3 mm × 7.5 mm footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (S) | Select Input | Common 2:1 selector for all four channels; logic HIGH routes I1x to Yx, LOW routes I0x to Yx |
| 2 (I0A) | Data Input A (Channel 0) | Bidirectional input/output for first 2:1 mux; connects to YA when E = L and S = L |
| 3 (I1A) | Data Input A (Channel 1) | Bidirectional input/output for first 2:1 mux; connects to YA when E = L and S = H |
| 4 (YA) | Data Output A | Common output node for Channel A; high-impedance when E = H or switch disabled |
| 5 (GND) | Ground Reference | Primary return path for all internal circuitry and I/O current; must be low-inductance connection |
| 6 (VCC) | Power Supply | 5 V ±5% supply for logic control and switch bias; decoupling required within 1 cm of pin |
| 7 (E) | Enable Input | Active-low global enable; drives all four channels into high-Z when HIGH |
| 8 (I0B) | Data Input B (Channel 0) | Bidirectional I/O for second channel; functionally identical to I0A but independent path |
| 9 (I1B) | Data Input B (Channel 1) | Bidirectional I/O for second channel; routed to YB per S state when E = L |
| 10 (YB) | Data Output B | Output for Channel B; electrically isolated from other outputs when disabled |
| 11 (I0D) | Data Input D (Channel 0) | Third independent bidirectional input pair; shares same control logic as others |
| 12 (I1D) | Data Input D (Channel 1) | Fourth independent bidirectional input pair; fully isolated signal path |
| 13 (YD) | Data Output D | Output for Channel D; maintains signal integrity up to 200 MHz due to low RON/CIN |
| 14 (I0C) | Data Input C (Channel 0) | Fourth channel input; pinout symmetry enables compact PCB layout with matched trace lengths |
| 15 (I1C) | Data Input C (Channel 1) | Fourth channel alternate input; supports simultaneous 4×2:1 switching without crosstalk |
| 16 (YC) | Data Output C | Output for Channel C; designed for low ground bounce via zero-current-switching architecture |
Key Features
| Feature | Design Value |
|---|---|
| Zero-propagation-delay switching | RC-limited delay < 0.25 ns ensures timing-critical signal paths (e.g., clock distribution, video sync) remain unaltered |
| Undershoot clamp diodes | Integrated clamps on all I/O and control pins protect against –3 V transient pulses without external components |
| Bidirectional 5 Ω switches | Low RON preserves rise/fall times and minimizes insertion loss across 0–200 MHz analog/video signals |
| Voltage translation capability | Supports 5 V ↔ 3.3 V domain bridging without level shifters due to wide input voltage range and TTL thresholds |
| Hot-swap compatible | High-impedance outputs during enable disable and built-in clamps allow safe insertion/removal in live backplanes |
Applications
| Video Signal Routing | Industrial Bus Funneling |
|---|---|
Use Scenario: Switching between dual HDMI source streams to a single display controller in broadcast equipment. IC Role / Device Role / Timing Role: Quad 2:1 analog mux routing RGB/CLK signals with sub-nanosecond delay consistency across all lanes. Use Value: Maintains pixel-perfect synchronization and eliminates skew-induced artifacts using matched 5 Ω RON and <10 pF channel capacitance. | Use Scenario: Consolidating multiple sensor data buses (RS-485, CAN, SPI) onto a single microcontroller interface in factory automation PLCs. IC Role / Device Role / Timing Role: Bidirectional bus funnel enabling time-multiplexed access to isolated peripheral networks without protocol translation. Use Value: Eliminates need for separate transceivers per bus; 5 V tolerant I/O allows direct connection to legacy industrial interfaces. |
| Hot-Swappable Module Interface | Legacy Logic Replacement |
Use Scenario: Enabling hot-plug insertion of daughter cards carrying FPGA configuration bitstreams in telecom line cards. IC Role / Device Role / Timing Role: Signal isolation gate that disconnects configuration lines during insertion, then re-enables with zero glitch. Use Value: Prevents back-driving and latch-up via high-Z state and undershoot clamps, meeting IEC 61000-4-2 Level 4 ESD immunity. | Use Scenario: Upgrading aging 74F257-based test fixture control logic to reduce power and improve reliability. IC Role / Device Role / Timing Role: Pin- and function-compatible drop-in replacement delivering identical logic behavior with lower ICCQ and higher noise margin. Use Value: Reduces quiescent current from ~20 mA to 3 μA and improves noise immunity via tighter VIH/VIL specs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad 2:1 mux/demux applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 74FCT257SO | Higher ON resistance (~15 Ω), no undershoot clamps, 20 mA ICCQ, non-RoHS | Limited to legacy 5V-only systems; unsuitable for hot-swap or mixed-voltage domains | Choose only if backward compatibility with existing 74FCT footprints is mandatory and thermal/power constraints are relaxed |
| SN74CBT3257PW | Similar 5 Ω RON, but requires 3.3 V supply only; VIH = 2.0 V min, no –0.5 V undershoot rating | Not suitable for 5 V logic interfacing or industrial transients; lacks integrated clamps | Prefer for new 3.3 V–only designs where TI's enhanced ESD spec (±8 kV HBM) is prioritized over voltage flexibility |
Compared with 74FCT257SO and SN74CBT3257PW, QS3257S1G8 uniquely combines 5 V operation, –0.5 V to +7 V I/O tolerance, integrated undershoot protection, and industrial temperature qualification - making it the only option qualified for mixed-domain hot-swap infrastructure in harsh environments.
Availability
QS3257S1G8 is available at Aetrix Electronics and suitable for industrial bus funneling, video signal routing, and hot-swappable module interface applications requiring stable component supply across extended lifecycle programs.
Supply support for QS3257S1G8 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, and enterprise systems.
The QS3257S1G8 belongs to Renesas' QuickSwitch® bus switch product line, engineered specifically for high-fidelity, low-latency signal routing in mixed-voltage, hot-pluggable, and noise-sensitive digital infrastructure.
FAQ
What is the maximum signal frequency supported by QS3257S1G8?
The QS3257S1G8 supports signal frequencies up to 200 MHz in practical applications, validated by its 5 Ω typical ON resistance and ≤10 pF channel capacitance. Its RC time constant (<0.25 ns) ensures minimal degradation of fast edges, making it suitable for HDMI, LVDS, and high-speed parallel bus routing where signal integrity is critical. The device does not specify an absolute bandwidth limit but performs reliably within this range under 50 pF load conditions.
Does QS3257S1G8 support level translation between 5V and 3.3V systems?
Yes, QS3257S1G8 supports bidirectional level translation between 5 V and 3.3 V domains. Its wide input voltage range (–0.5 V to +7 V) and TTL-compatible control thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V) allow direct interfacing with both logic families. When used with 5 V VCC, the switch passes 3.3 V signals without clipping or distortion, and control inputs accept 3.3 V logic levels as valid HIGH/LOW states.
Is QS3257S1G8 pin-compatible with standard 74-series logic devices?
Yes, QS3257S1G8 is explicitly pin- and function-compatible with 74F257, 74FCT257, and 74ALS/AS/LS257 quad 2:1 multiplexers. Its S1 package matches the 16-pin SOIC footprint, and the pin mapping (including E, S, I0x/I1x, and Yx assignments) aligns exactly with those legacy parts - enabling drop-in replacement without PCB redesign or firmware changes.
What protection features does QS3257S1G8 include for rugged industrial use?
QS3257S1G8 integrates undershoot clamp diodes on all switch and control inputs, rated for –3 V transient pulses (AC input voltage). It also supports operation from –40°C to +85°C and tolerates –0.5 V to +7 V on all I/O pins except VCC. These features collectively enable robust performance in industrial environments with noisy power rails, electrostatic discharge events, and thermal cycling - eliminating the need for external TVS or series resistors in most implementations.
Can QS3257S1G8 be used in hot-swap applications?
Yes, QS3257S1G8 is designed for hot-swap applications. Its active-high-impedance outputs (when E = HIGH), integrated undershoot clamps, and zero ground bounce architecture prevent back-driving, latch-up, or signal corruption during live insertion/removal. Combined with its wide voltage tolerance and industrial temperature range, it meets key requirements for modular computing, telecom line cards, and field-replaceable I/O units.
QS3257S1G8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Multiplexer/Demultiplexer
- Circuit:
- 4 x 2:1
- Independent Circuits:
- 1
- Current - Output High, Low:
- -
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
QS3257S1G8 FAQ
1.How can I place an order for QS3257S1G8 through Aetrix?
Please submit a Request for Quotation (RFQ) for QS3257S1G8 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 QS3257S1G8 reliable?
The price and inventory of QS3257S1G8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for QS3257S1G8 is usually 5 days.
3.What payment methods are accepted for QS3257S1G8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for QS3257S1G8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for QS3257S1G8?
QS3257S1G8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your QS3257S1G8 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 QS3257S1G8?
For technical support, including QS3257S1G8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your QS3257S1G8 requirements.
6.How does Aetrix verify that QS3257S1G8 is sourced from the original manufacturer or authorized distributors?
All QS3257S1G8 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 QS3257S1G8 meets industry standards.
7.What is the process for return or replacement of QS3257S1G8?
All QS3257S1G8 units undergo pre-shipment inspection (PSI). If there is an issue with QS3257S1G8, 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 QS3257S1G8 part is unused and in its original packaging.
Return procedure for QS3257S1G8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
QS3257S1G8 Tags
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