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Renesas QS3244QG
- Part No.:
- QS3244QG
- Manufacturer:
- Renesas
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 20-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
QS3244QG.pdf
- Description:
- IC BUS SWITCH 4 X 1:1 20QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:114
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Product details
Overview
QS3244QG from Renesas Electronics is an 8-bit high-speed CMOS bus switch with bidirectional 5Ω ON-resistance, TTL-compatible pinout matching 74FCT244/74F244, and industrial temperature range (–40°C to +85°C). It enables zero-propagation-delay data routing, hot-swap isolation, and 5V-to-3.3V voltage translation in backplane and I/O expansion systems.
For engineers reviewing the QS3244QG datasheet, QS3244QG pinout, QS3244QG application, or QS3244QG equivalent, key selection criteria include guaranteed sub-0.25ns propagation delay, undershoot clamp diodes on all control/data pins, dual independent enable inputs (1G/2G), and RoHS-compliant QSOP-20 green package compatibility.
Technical Context
The QS3244QG implements eight independent N-channel FET switches with no inherent body diode to VCC, enabling true bidirectional signal flow without forward-bias risk. Its control logic uses two active-low enable signals (1G, 2G) that mirror the 74'244 architecture, allowing direct drop-in replacement in legacy driver designs.
Each switch exhibits 5Ω typical ON resistance at VCC = 5V and VIN = 0V, with pass voltage of 3.7–4.2V under 5μA load - critical for maintaining logic HIGH integrity across voltage-translating interfaces. Input leakage remains ≤±1μA over full temperature range, supporting low-power system standby modes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| ON Resistance | 5Ω typical at VCC = 5V, 0V input - ensures minimal RC delay and preserves signal rise/fall times in high-speed buses |
| Propagation Delay | <0.25ns max - contributes negligible delay beyond system RC time constant; no added ground bounce |
| Operating Temp | –40°C to +85°C - qualified for industrial control, telecom line cards, and embedded computing environments |
| Voltage Range | –0.5V to +7V on all I/O and control pins - supports robust hot-swap transients and undershoot clamping |
| Enable Inputs | Two independent active-low enables (1G, 2G) - allows selective activation of Group 1 (1A1–1Y4) or Group 2 (2A1–2Y4) |
| Package | 20-pin QSOP (QG suffix) - 0.65mm pitch, 7.2mm × 4.4mm footprint, compatible with automated SMT assembly |
Pinout & Package
QS3244QG is housed in a 20-pin Quarter Size Outline Package (QSOP), RoHS-compliant and moisture-sensitive level 3 (MSL3). The package supports fine-pitch surface-mount assembly and thermal dissipation up to 0.5W at TA = 85°C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1G, 2G | Active-Low Output Enable | Controls conduction state of Group 1 (pins 2–9) or Group 2 (pins 12–19); logic LOW enables switch path |
| 1A1–1A4, 1Y1–1Y4 | Bidirectional Data I/O (Group 1) | Four independent A↔Y pairs; 5Ω ON-resistance enables lossless signal coupling in either direction |
| 2A1–2A4, 2Y1–2Y4 | Bidirectional Data I/O (Group 2) | Second set of four A↔Y pairs, electrically isolated from Group 1 when respective enable is HIGH |
| VCC (Pin 11) | Positive Supply | 5V ±5% supply input; powers internal clamp diodes and switch bias circuitry |
| GND (Pin 10) | Ground Reference | Common return for all I/Os and control logic; critical for noise immunity and clamp diode operation |
Key Features
| Feature | Design Value |
|---|---|
| Zero-propagation-delay switching | RC-limited delay <0.25ns with 50pF load - eliminates timing budget penalties in synchronous bus architectures |
| Undershoot clamp diodes | Integrated clamps on all A/Y and G pins - suppresses –3V transients during hot-plug events without external components |
| 5Ω bidirectional ON resistance | Consistent conduction in both directions with no diode drop - enables true voltage-level agnostic signal routing |
| Pin compatibility with 74FCT244 | Direct PCB replacement for legacy 8-bit drivers - no layout change required for upgrade to QuickSwitch performance |
| Industrial temperature rating | Full functionality from –40°C to +85°C - validated for use in uncontrolled ambient environments like factory automation panels |
Applications
| Hot-Swappable Backplane Interface | Voltage-Translating I/O Expansion |
|---|---|
Use Scenario: Inserting/removing mezzanine cards in powered telecom chassis without disrupting main CPU bus. IC Role / Device Role / Timing Role: Bidirectional isolation switch between 5V backplane and 3.3V card-side logic; enables safe insertion detection via enable pin sequencing. Use Value: Prevents bus contention and power rail collapse during hot-dock events using undershoot clamps and zero-delay switching. | Use Scenario: Interfacing 5V microcontroller GPIOs to 3.3V sensor peripherals in industrial PLC modules. IC Role / Device Role / Timing Role: Level-shifting bus switch with no direction control pins - simplifies firmware by eliminating direction register management. Use Value: Maintains TTL-compatible thresholds while translating voltage, with 5Ω RON preserving signal edge rates up to 100MHz. |
| Low-Power Clock Gating | Capacitance-Isolated Bus Segmentation |
Use Scenario: Dynamically disabling clock distribution to inactive subsystems in battery-powered edge gateways. IC Role / Device Role / Timing Role: Low-leakage (±1μA) switch inserted in clock path; enabled only during active computation cycles. Use Value: Reduces dynamic power by >95% in gated domains while avoiding clock skew from added gate delay. | Use Scenario: Partitioning high-density PCBs into electrically isolated functional blocks to meet EMI limits. IC Role / Device Role / Timing Role: Signal isolator with 5–7pF OFF-state capacitance - minimizes crosstalk between RF and digital sections. Use Value: Cuts inter-segment coupling by >20dB compared to passive trace routing, without requiring series resistors or ferrites. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bus switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74CBT3244PWR | Higher typical RON (6.5Ω), same pinout, TI's CBT family - slightly higher propagation uncertainty due to process variation | Validated for automotive AEC-Q100 Grade 2; QS3244QG lacks automotive qualification | Choose SN74CBT3244PWR for automotive-grade deployments where extended temperature validation is mandatory |
| 74FCT244CTSO20 | Traditional TTL-output buffer (not a switch); 3-state outputs only; no bidirectional capability or undershoot clamps | Provides drive strength (24mA) but adds propagation delay (~5ns) and requires direction control logic | Choose 74FCT244CTSO20 only if output buffering (not isolation/translation) is the primary requirement |
Compared with SN74CBT3244PWR and 74FCT244CTSO20, the QS3244QG uniquely delivers bidirectional zero-delay switching with integrated transient protection - making it optimal for hot-swap and voltage-translation use cases where signal integrity and simplicity are prioritized over drive strength or automotive certification.
Availability
QS3244QG is available at Aetrix Electronics and suitable for hot-swappable backplanes, voltage-translating I/O expansion, and low-power clock gating applications requiring stable component supply across industrial design cycles.
Supply support for QS3244QG 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 QS3244QG belongs to Renesas' QuickSwitch® bus switch product line, engineered specifically for high-speed signal isolation, voltage translation, and hot-swap robustness in mission-critical industrial and telecom systems.
FAQ
What is the maximum operating voltage for QS3244QG I/O pins?
The QS3244QG supports DC input voltages from –0.5V to +7V on all A, Y, and control pins (per Absolute Maximum Ratings). This wide range accommodates hot-swap transients and enables safe 5V-to-3.3V translation without level shifters. The VCC pin operates at 5V ±5%, and the device maintains specified performance within this supply window.
Does QS3244QG support bidirectional signal flow?
Yes, QS3244QG supports true bidirectional signal flow through each A↔Y pair. Its enhanced N-channel FET structure has no inherent body diode to VCC, eliminating forward-bias limitations. Signals propagate identically in either direction with 5Ω typical ON resistance, making it ideal for data buses requiring flexible read/write paths.
Is QS3244QG pin-compatible with standard 74-series logic devices?
Yes, QS3244QG is pin-compatible with 74FCT244, 74F244, and 74ALS/AS/LS244 octal buffers. Its 20-pin QSOP layout matches these legacy drivers, enabling drop-in replacement without PCB redesign. However, unlike those devices, QS3244QG provides zero-delay switching instead of buffered output drive.
What is the purpose of the undershoot clamp diodes in QS3244QG?
The undershoot clamp diodes on all A, Y, and G pins protect against negative transients down to –3V (AC) or –0.5V (DC). They prevent latch-up and damage during hot-insertion events by shunting energy to GND. This eliminates the need for external TVS diodes in hot-swap interfaces, reducing BOM count and board area.
How does QS3244QG achieve zero propagation delay?
QS3244QG achieves effectively zero propagation delay because its 5Ω ON resistance forms an RC network with load capacitance - resulting in a time constant of ~0.25ns at 50pF. Since this is far smaller than typical signal rise/fall times, the switch adds no measurable delay beyond the inherent system RC limit. Propagation is thus dominated by driving and load circuitry, not the switch itself.
QS3244QG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 20-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Bus Switch
- Circuit:
- 4 x 1:1
- Independent Circuits:
- 2
- 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:
- 20-QSOP
QS3244QG FAQ
1.How can I place an order for QS3244QG through Aetrix?
Please submit a Request for Quotation (RFQ) for QS3244QG 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 QS3244QG reliable?
The price and inventory of QS3244QG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for QS3244QG is usually 5 days.
3.What payment methods are accepted for QS3244QG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for QS3244QG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for QS3244QG?
QS3244QG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your QS3244QG 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 QS3244QG?
For technical support, including QS3244QG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your QS3244QG requirements.
6.How does Aetrix verify that QS3244QG is sourced from the original manufacturer or authorized distributors?
All QS3244QG 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 QS3244QG meets industry standards.
7.What is the process for return or replacement of QS3244QG?
All QS3244QG units undergo pre-shipment inspection (PSI). If there is an issue with QS3244QG, 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 QS3244QG part is unused and in its original packaging.
Return procedure for QS3244QG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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