My Inquiry
My Account
Renesas QS3245QG
- Part No.:
- QS3245QG
- Manufacturer:
- Renesas
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 20-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
QS3245QG.pdf
- Description:
- IC BUS SWITCH 8 X 1:1 20QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,766
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
QS3245QG from Renesas Electronics is an 8-bit high-speed CMOS bus switch with TTL-compatible control inputs, 5Ω typical ON resistance, zero propagation delay, and industrial temperature range (–40°C to +85°C). It functions as a bidirectional signal path selector for data buses in hot-swap and voltage-translation applications.
For engineers reviewing the QS3245QG datasheet, QS3245QG pinout, QS3245QG application, or QS3245QG equivalent, key selection criteria include its 5Ω RON, OE-controlled bidirectional switching, undershoot clamp diodes on all I/Os, and compatibility with 74FCT245/74F245 pinouts in SOIC/QSOP packages.
Technical Context
The QS3245QG implements eight independent N-channel FET switches with no inherent body diode to VCC, enabling true bidirectional signal flow without DC blocking or level-shifting constraints. Its OE input directly controls all eight channels synchronously, mirroring the 74'245 transceiver logic interface.
It operates at 5V ±5%, supports DC switch voltages from –0.5V to +7V on all terminals except VCC, and delivers sub-nanosecond turn-on/turn-off delays (tPZL ≤ 5.6 ns, tPLZ ≤ 4.5 ns) under 50 pF load conditions - enabled by low intrinsic capacitance (≤7 pF per channel off-state) and minimal RC time constant.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| ON Resistance (RON) | 5 Ω typical at VCC = 5V, VIN = 0V - enables low-loss signal pass-through with negligible voltage drop at ≤30 mA. |
| Propagation Delay | Not applicable (zero added delay) - signal delay determined solely by external RC load, not internal logic. |
| Supply Voltage Range | –0.5 V to +7 V on all pins except VCC - supports robust fault tolerance and mixed-voltage domain interfacing. |
| Input Voltage Levels | VIH ≥ 2 V, VIL ≤ 0.8 V - ensures reliable TTL-compatible OE control without level shifters. |
| Off-State Leakage | ±0.001 μA typical - maintains high-impedance isolation between buses during disable state. |
| Capacitance (off) | 7 pF max per channel - minimizes loading on driving sources and preserves signal integrity in high-speed buses. |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded and infrastructure systems. |
Pinout & Package
QS3245QG is packaged in a 20-pin QSOP (Quarter Size Outline Package), green RoHS-compliant, with 0.65 mm lead pitch and standard JEDEC MO-137 footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (NC) | No Connect | Unbonded pad; must be left floating or tied to GND per layout guidelines. |
| 2–9, 11–18 (A0–A7, B0–B7) | Bidirectional Data I/O | Eight independent switch channels; each pair Ax/Bx connects bidirectionally when OE is active low. |
| 10 (GND) | Ground Reference | Primary return path for all internal circuitry and I/O current sinks. |
| 19 (VCC) | Power Supply | 5V ±5% supply input; decoupling capacitor required within 1 cm of pin. |
| 20 (OE) | Output Enable | Active-low control: OE = L enables all eight switches; OE = H places all outputs in high-Z state. |
Key Features
| Feature | Design Value |
|---|---|
| Zero-propagation-delay switching | Eliminates timing skew in synchronous bus architectures - critical for clock gating and hot-swap arbitration. |
| Undershoot clamp diodes on all I/Os | Protects against negative transients down to –3 V (AC) and –0.5 V (DC), enabling safe operation in noisy industrial environments. |
| TTL-compatible control inputs | Accepts standard 5V TTL logic levels without external biasing - simplifies integration with legacy microcontrollers and FPGAs. |
| 5Ω low ON resistance | Ensures <10 mV voltage drop at 2 mA, preserving signal amplitude integrity across 3.3V/5V translation paths. |
| Pin compatibility with 74FCT245/74F245 | Enables drop-in replacement in existing PCB layouts using SOIC-20 or QSOP-20 footprints - reduces redesign effort. |
Applications
| Hot-Swapping Systems | Voltage Translation (5V ↔ 3.3V) |
|---|---|
Use Scenario: Insertion/removal of PCIe add-in cards or modular backplane blades while system remains powered. IC Role / Device Role / Timing Role: Bidirectional bus isolator that enables/disables data path under firmware control via OE signal. Use Value: Prevents bus contention and ground bounce during plug events; supports IEEE 1184-compliant hot-swap sequencing. | Use Scenario: Interfacing 5V legacy peripherals (e.g., UART, SPI flash) with 3.3V SoCs in industrial gateways. IC Role / Device Role / Timing Role: Passive level translator with no direction control or power supply requirements beyond VCC. Use Value: Maintains signal integrity without adding propagation delay or requiring external pull-ups/downs. |
| Logic Replacement (Data Processing) | Bus Switching and Isolation |
Use Scenario: Replacing 74FCT245 transceivers in FPGA I/O expansion modules where direction control adds complexity. IC Role / Device Role / Timing Role: Unidirectional or bidirectional data path enabler controlled only by OE - no DIR pin needed. Use Value: Reduces control logic overhead and eliminates direction-mismatch faults in fixed-data-flow subsystems. | Use Scenario: Isolating CPU memory bus from diagnostic test equipment during field service operations. IC Role / Device Role / Timing Role: High-Z barrier with <7 pF off-state capacitance - prevents capacitive loading and crosstalk leakage. Use Value: Enables clean bus segmentation without signal reflection or timing margin degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bus switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74CBT3245APWR | 5.5Ω RON, same 20-pin TSSOP package, but lacks undershoot clamps on A/B pins. | Less robust in high-noise industrial environments; requires external protection diodes for –3V transient immunity. | Preferred where cost sensitivity outweighs transient protection needs and layout space allows discrete clamping. |
| 74LVC245APW | Direction-controlled transceiver (DIR pin required), 3.3V-only supply, higher propagation delay (~3.5 ns). | Cannot replace QS3245QG without modifying OE logic and adding direction control signals. | Only suitable when bidirectional control and 5V tolerance are not required, and board redesign is acceptable. |
Compared with SN74CBT3245APWR and 74LVC245APW, the QS3245QG uniquely combines 5V tolerance, integrated undershoot clamps, zero-delay switching, and pin compatibility with legacy 74FCT245 layouts - making it optimal for industrial hot-swap and mixed-voltage isolation where reliability and drop-in upgradeability are critical.
Availability
QS3245QG is available at Aetrix Electronics and suitable for hot-swapping systems, voltage translation interfaces, and bus isolation applications requiring stable component supply across extended industrial temperature ranges.
Supply support for QS3245QG 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 IoT applications.
The QS3245QG belongs to Renesas' QuickSwitch® bus switch product line, engineered specifically for zero-delay, high-reliability signal routing in hot-plug-capable and mixed-voltage digital systems.
FAQ
What is the maximum allowable voltage on QS3245QG I/O pins when VCC = 5V?
The QS3245QG permits DC input voltages from –0.5 V to +7 V on all pins except VCC (per Absolute Maximum Ratings). This allows safe interfacing with 3.3V, 5V, and even 7V logic domains without level shifters - critical for voltage translation and fault-tolerant designs. The device includes undershoot clamp diodes rated to –3 V for AC pulses ≤20 ns.
Does QS3245QG require external pull-up or pull-down resistors on its A/B pins?
No, QS3245QG does not require external pull-up or pull-down resistors on A or B pins. Its enhanced N-channel FET structure has no inherent body diode to VCC, eliminating DC leakage paths. When OE is high, all channels present high-Z isolation with ±0.001 μA off-state leakage - sufficient for most bus-hold-free applications without added components.
Is QS3245QG pin-compatible with 74FCT245 in both SOIC and QSOP packages?
Yes, QS3245QG is explicitly pin-compatible with 74FCT245, 74F245, and 74FCT245T in both SOIC-20 and QSOP-20 packages. Pin mapping matches exactly: OE at pin 20, GND at pin 10, VCC at pin 19, and A/B I/Os occupy identical positions - enabling direct PCB-level replacement without layout changes.
What is the typical power consumption of QS3245QG during active switching?
QS3245QG draws only 0.25 mA/MHz dynamic supply current (ICCD) on control inputs when toggling at 50% duty cycle; A/B pins generate no significant AC or DC current. Quiescent current (ICCQ) is just 3 μA max at VCC = 5.5V. This ultra-low power profile supports energy-sensitive industrial and portable applications without thermal derating.
Can QS3245QG be used for clock gating applications?
Yes, QS3245QG is well-suited for clock gating due to its zero-propagation-delay architecture and fast turn-on/turn-off times (tPZL ≤ 5.6 ns, tPLZ ≤ 4.5 ns). Its 5Ω RON introduces negligible jitter or duty-cycle distortion, and the OE pin allows precise synchronous enable/disable of clock paths - commonly deployed in FPGA-based timing control and low-power SoC subsystems.
QS3245QG 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:
- 8 x 1:1
- 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:
- 20-QSOP
QS3245QG FAQ
1.How can I place an order for QS3245QG through Aetrix?
Please submit a Request for Quotation (RFQ) for QS3245QG 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 QS3245QG reliable?
The price and inventory of QS3245QG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for QS3245QG is usually 5 days.
3.What payment methods are accepted for QS3245QG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for QS3245QG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for QS3245QG?
QS3245QG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your QS3245QG 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 QS3245QG?
For technical support, including QS3245QG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your QS3245QG requirements.
6.How does Aetrix verify that QS3245QG is sourced from the original manufacturer or authorized distributors?
All QS3245QG 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 QS3245QG meets industry standards.
7.What is the process for return or replacement of QS3245QG?
All QS3245QG units undergo pre-shipment inspection (PSI). If there is an issue with QS3245QG, 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 QS3245QG part is unused and in its original packaging.
Return procedure for QS3245QG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
QS3245QG 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
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
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…
