My Inquiry
My Account
Renesas 74FST6800QG
- Part No.:
- 74FST6800QG
- Manufacturer:
- Renesas
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 24-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
74FST6800QG.pdf
- Description:
- IC BUS SWITCH 10 X 1:1 24QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,785
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
74FST6800QG from Renesas Electronics (formerly IDT) is a 10-bit TTL-compatible bus switch with precharged outputs, designed for high-speed signal routing in industrial logic systems. It features 7Ω on-resistance, 0.25ns max propagation delay, and hot-insertion capability with VCC = 0V operation. Used in backplane interconnects and hot-swap I/O expansion modules.
For engineers reviewing the 74FST6800QG datasheet, 74FST6800QG pinout, 74FST6800QG application, or 74FST6800QG equivalent, key selection criteria include precharge-enabled output isolation, industrial temperature range (–40°C to +85°C), QSOP-24 package compatibility, and low-noise zero-delay switching behavior under TTL-level control.
Technical Context
The 74FST6800QG implements an n-channel FET-based bus switch architecture with active-low enable (ON) and dedicated BIASV input for controlled precharge of B-side outputs. Its gate biasing enables true hot-plug operation without VCC applied.
When ON is HIGH, A–B paths are open and B outputs are pulled to BIASV via internal ~10kΩ resistors; when ON is LOW, bidirectional conduction occurs with <7Ω RON and sub-nanosecond RC-limited delay. No internal current sourcing/sinking capability exists - all drive must be provided externally.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.75V to 5.25V - supports standard 5V TTL rail with ±5% tolerance |
| RON (Max) | 7Ω at VCC = 4.75V, ION = 64mA - ensures minimal voltage drop and signal integrity across loaded buses |
| tPLH/tPHL (Max) | 0.25ns - contributes negligible propagation delay beyond driver/load RC time constant |
| tPZH/tPHZ (Max) | 6.5ns / 5.5ns - defines worst-case enable/disable timing for synchronous bus gating |
| IO (Precharge) | 0.15mA at BIASV = 2.4V - sets precharge slew rate and noise margin during output float-to-bias transition |
| ESD Rating | >2000V HBM, >200V MM - meets MIL-STD-883 Class 3A requirements for industrial handling robustness |
| TA Operating Range | –40°C to +85°C - qualified for extended industrial ambient conditions without derating |
Pinout & Package
74FST6800QG is housed in a 24-pin QSOP (Quarter-size Small Outline Package – Green), 0.150" body width, 0.635mm lead pitch, JEDEC MO-137 compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1–A10 | Input/Output Port A | Bidirectional data path terminal; connects to upstream logic or controller side |
| B1–B10 | Input/Output Port B | Bidirectional data path terminal; connects to downstream bus or peripheral side |
| ON | Active-Low Enable | Drives switch state: LOW = A↔B connected; HIGH = A isolated, B precharged to BIASV |
| BIASV | Precharge Reference Voltage | Sets DC level for B-port precharge; may be tied to VCC, GND, or intermediate bias |
| VCC | Power Supply | Supplies gate bias for FET switches; required for normal operation but not for hot-insertion mode |
| GND | Ground Reference | Common return for all signal and power paths; critical for ESD path integrity |
Key Features
| Feature | Design Value |
|---|---|
| Zero-delay signal path | RC-limited propagation (≤0.25ns) eliminates added timing skew in synchronous bus architectures |
| Hot-insertion support | Functional isolation with VCC = 0V enables live board replacement without system shutdown |
| Precharged B-port outputs | Internal ~10kΩ pull-up/down to BIASV prevents floating states during disable, reducing EMI and latch-up risk |
| TTL-compatible I/O levels | VIH ≥ 2.0V, VIL ≤ 0.8V - interoperates directly with legacy 5V TTL, LVTTL, and CMOS logic families |
| Low on-resistance (7Ω) | Minimizes insertion loss and maintains signal edge fidelity up to 100MHz+ data rates |
Applications
| Backplane Signal Routing | Hot-Swap I/O Module Interface |
|---|---|
Use Scenario: Isolating redundant CPU-to-peripheral communication paths in modular industrial PLC chassis. IC Role / Device Role / Timing Role: Bidirectional bus gate enabling/disabling data flow between master and slave slots under firmware control. Use Value: Prevents bus contention during module insertion/removal while maintaining deterministic timing with <0.25ns added delay. | Use Scenario: Managing signal handoff between hot-pluggable sensor interface cards and main controller backplane. IC Role / Device Role / Timing Role: Precharge-controlled bus switch ensuring B-side outputs settle to known state before connection. Use Value: Eliminates glitches and metastability during card insertion by holding B ports at BIASV until ON is asserted. |
| Legacy TTL Bus Expansion | Test Equipment Signal Multiplexing |
Use Scenario: Extending 5V TTL data/address bus length across multiple PCBs in automated test fixtures. IC Role / Device Role / Timing Role: Low-RON repeater preserving signal rise/fall times and noise margins over distributed traces. Use Value: Maintains VIH/VIL margins across 20cm+ trace runs without active buffering or level translation. | Use Scenario: Routing DUT signals to multiple measurement instruments (oscilloscope, logic analyzer, DMM) without cross-talk. IC Role / Device Role / Timing Role: Zero-delay multiplexer selecting one of several parallel signal paths under digital control. Use Value: Enables glitch-free channel switching at up to 100MHz due to absence of internal storage or clocking. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bus switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74CBT16210DGGR | 12-bit, 5V-only, 6Ω RON, no precharge; TSSOP-56 package | Lacks BIASV-controlled precharge; requires external pull-ups for float-state management | Preferred where higher channel count and lower RON outweigh need for integrated precharge |
| 74LVC1G3157GW,125 | Single-pole double-throw analog switch, 3.3V only, 10Ω RON, no precharge | Not pin-compatible; requires redesign for 10-bit parallel use; lacks industrial temp rating | Suitable for low-voltage, space-constrained designs where full 10-bit integration is unnecessary |
Compared with SN74CBT16210DGGR and 74LVC1G3157GW,125, the 74FST6800QG uniquely delivers precharged output control in a compact 24-pin QSOP, enabling robust hot-swap operation in 5V industrial systems without external bias circuitry.
Availability
74FST6800QG is available at Aetrix Electronics and suitable for industrial backplane routing, hot-swap I/O modules, and legacy TTL bus expansion requiring stable component supply across long production lifecycles.
Supply support for 74FST6800QG 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 infrastructure markets.
The 74FST6800QG belongs to Renesas' legacy IDT logic portfolio, engineered specifically for zero-delay, noise-immune bus switching in harsh industrial environments with hot-plug and precharge requirements.
FAQ
What is the function of the BIASV pin on the 74FST6800QG?
The BIASV pin on the 74FST6800QG sets the DC voltage level to which B1–B10 outputs are precharged when the ON pin is HIGH. Internally, each B-port connects through a ~10kΩ resistor to BIASV, preventing floating states and reducing EMI during disable. BIASV may be tied to VCC, GND, or an intermediate reference depending on system noise and logic threshold requirements. This feature is integral to the 74FST6800QG's hot-swap capability.
Does the 74FST6800QG support hot insertion with VCC unpowered?
Yes, the 74FST6800QG supports true hot insertion with VCC = 0V. When unpowered, the internal n-channel FETs remain off, isolating A and B ports. No current flows through the switch, and inputs/outputs exhibit high-impedance behavior per MIL-STD-883 ESD ratings. This behavior is explicitly guaranteed in the 74FST6800QG datasheet and forms the basis of its use in live-backplane systems.
What is the maximum continuous current per channel for the 74FST6800QG?
The 74FST6800QG specifies a maximum continuous channel current (IOUT) of 128mA per A–B path. This rating applies under industrial temperature conditions (–40°C to +85°C) and ensures reliable conduction without thermal runaway or parametric shift. Exceeding this limit risks permanent degradation of the FET channel resistance and is not recoverable. The 74FST6800QG's 7Ω RON yields ≤0.896V drop at 128mA, aligning with TTL noise margin constraints.
Can the 74FST6800QG be used with 3.3V logic systems?
No, the 74FST6800QG is specified only for 5V operation (VCC = 4.75V to 5.25V) and TTL-compatible input thresholds (VIH ≥ 2.0V, VIL ≤ 0.8V). While 3.3V logic may meet VIL, it fails VIH margin and risks unreliable enable/disable behavior. Additionally, RON increases significantly below 4.75V, degrading signal integrity. For 3.3V systems, consider Renesas' 74LVC series or similar - the 74FST6800QG is not rated or characterized for 3.3V use.
What package type does the 74FST6800QG use, and is it RoHS-compliant?
The 74FST6800QG uses a 24-pin QSOP (Quarter-size Small Outline Package – Green), designated "QG" in the ordering code. It is RoHS-compliant and halogen-free, as confirmed in the Renesas ordering information table and material declaration documents. The package has 0.635mm lead pitch, 0.150" body width, and meets JEDEC MO-137 standards - identical to industry-standard 24-pin QSOP footprints used in automated assembly.
74FST6800QG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- 74FST
- Package/Case:
- 24-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- Bus Switch
- Circuit:
- 10 x 1:1
- Independent Circuits:
- 1
- Current - Output High, Low:
- -
- Voltage Supply Source:
- Single Supply
- Voltage - Supply:
- -
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 24-QSOP
74FST6800QG FAQ
1.How can I place an order for 74FST6800QG through Aetrix?
Please submit a Request for Quotation (RFQ) for 74FST6800QG 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 74FST6800QG reliable?
The price and inventory of 74FST6800QG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74FST6800QG is usually 5 days.
3.What payment methods are accepted for 74FST6800QG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74FST6800QG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74FST6800QG?
74FST6800QG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74FST6800QG 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 74FST6800QG?
For technical support, including 74FST6800QG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74FST6800QG requirements.
6.How does Aetrix verify that 74FST6800QG is sourced from the original manufacturer or authorized distributors?
All 74FST6800QG 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 74FST6800QG meets industry standards.
7.What is the process for return or replacement of 74FST6800QG?
All 74FST6800QG units undergo pre-shipment inspection (PSI). If there is an issue with 74FST6800QG, 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 74FST6800QG part is unused and in its original packaging.
Return procedure for 74FST6800QG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
74FST6800QG 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…
