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Texas Instruments 74CB3Q3305DCURE4
- Part No.:
- 74CB3Q3305DCURE4
- Manufacturer:
- Texas Instruments
- Category:
- Signal Switches, Multiplexers, Decoders
- Package:
- 8-VFSOP (0.091", 2.30mm Width)
- Datasheet:
-
74CB3Q3305DCURE4.pdf
- Description:
- IC BUS SWITCH 1 X 1:1 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,132
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Product details
Overview
74CB3Q3305DCURE4 from Texas Instruments is a dual 1-bit FET bus switch optimized for high-bandwidth signal routing in 2.5-V/3.3-V systems, featuring 3 Ω typical ON-state resistance, 5-V tolerant I/Os (operating or powered down), and rail-to-rail 0–5-V switching with 3.3-V VCC - deployed in optical networking and USB differential interface isolation.
For engineers reviewing the 74CB3Q3305DCURE4 datasheet, 74CB3Q3305DCURE4 pinout, 74CB3Q3305DCURE4 application, or 74CB3Q3305DCURE4 equivalent, this page delivers verified functional modes, real-world timing behavior (0.15 ns propagation delay at 3.3 V), IOFF-enabled partial-power-down support, and validated alternatives for bus isolation upgrades in broadband communications hardware.
Technical Context
The 74CB3Q3305DCURE4 implements two independent bidirectional 1-bit switches, each controlled by dedicated OE inputs (1OE, 2OE), enabling discrete channel enable/disable without affecting the other path. Its charge-pump gate drive ensures flat ron across voltage and temperature, supporting rail-to-rail analog/digital signal pass-through with near-zero propagation delay.
Each switch supports 5-V tolerant I/Os regardless of VCC state (2.3–3.6 V), and features IOFF circuitry that blocks current backflow during partial power-down - critical for hot-swap and mixed-voltage system interoperability. The device operates up to 500 MHz small-signal bandwidth with 3.5 pF typical OFF-state I/O capacitance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.3 V to 3.6 V - enables compatibility with both 2.5-V and 3.3-V logic domains without level shifters. |
| ron (Typical) | 3 Ω - ensures minimal insertion loss and signal distortion for high-speed data paths up to 500 MHz. |
| I/O Capacitance (OFF) | 3.5 pF typical - reduces capacitive loading on buses, preserving signal integrity in dense PCB layouts. |
| Propagation Delay | 0.15 ns at 3.3 V - enables sub-nanosecond timing-critical switching in USB and optical module control paths. |
| Switching Frequency (fOE) | 20 MHz maximum - supports fast enable/disable cycling for dynamic bus arbitration in networking equipment. |
| IOFF Current | 1 µA at VCC = 0 - guarantees robust isolation and zero backfeed during system power sequencing. |
| ESD Rating (HBM) | 2000 V - meets industrial-grade handling requirements without external protection diodes. |
Pinout & Package
VSSOP-8 package (2.00 mm × 3.10 mm body size, 0.5-mm pitch), thin-profile surface-mount design optimized for space-constrained optical modules and high-density telecom PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1OE | Channel 1 output enable input | Active-high control: drives associated switch ON (A↔B connected) when high; high-impedance isolation when low. |
| 1A / 1B | Bidirectional data ports for channel 1 | Passes signals in either direction with <3 Ω ron; supports 0–5 V signaling regardless of VCC state. |
| 2OE | Channel 2 output enable input | Independent enable for second switch - allows asynchronous control of dual isolated data paths. |
| 2A / 2B | Bidirectional data ports for channel 2 | Electrically identical to 1A/1B; no crosstalk between channels per datasheet characterization. |
| GND | Ground reference | Common return for all internal circuitry; must be low-inductance connection for stable charge-pump operation. |
| VCC | Power supply | Supplies internal charge pump and logic; powers I/O buffers - tolerant of 2.3–3.6 V range with full functionality. |
Key Features
| Feature | Design Value |
|---|---|
| Charge-pump gate drive | Maintains flat 3 Ω ron across full VCC (2.3–3.6 V) and temperature range (–40°C to +85°C), eliminating signal-dependent attenuation. |
| 5-V tolerant I/Os | Allows direct interfacing with 5-V peripherals (e.g., legacy USB PHYs or optical transceivers) while powered from 2.5-V or 3.3-V rails - no external level shifters required. |
| IOFF partial-power-down | Prevents damaging current flow from live 5-V buses into unpowered sections - essential for hot-plug optical modules and modular PBX systems. |
| Rail-to-rail analog switching | Supports 0–5 V analog/digital signals with 3.3-V VCC, enabling use in video-over-fiber bias control and EPON burst-mode receiver signal routing. |
| Low 3.5 pF OFF-state capacitance | Minimizes stub effects and reflections on high-speed traces - critical for maintaining >1 Gbps eye diagrams in WiMAX baseband interfaces. |
Applications
| Optical Networking: EPON | USB Differential Signal Interface |
|---|---|
Use Scenario: Isolating upstream/downstream burst-mode data paths in Ethernet Passive Optical Network (EPON) OLT line cards. IC Role / Device Role / Timing Role: Dual-channel bidirectional bus switch providing low-latency, rail-to-rail signal pass-through between GPON MAC and burst-mode receiver/transmitter ASICs. Use Value: 0.15 ns propagation delay preserves timing margins for 1.25 Gbps burst synchronization; 5-V tolerance accommodates legacy optical driver voltages without level translation. |
Use Scenario: Enabling/disabling USB 2.0 differential pairs during host controller enumeration or port power management. IC Role / Device Role / Timing Role: Low-capacitance, bidirectional switch isolating D+/D− lines between USB PHY and connector during suspend/resume cycles. Use Value: 3.5 pF Cio(OFF) prevents signal degradation on 480 Mbps high-speed USB traces; IOFF blocks leakage during USB suspend (VCC = 0). |
| IP Phones: Wired and Wireless | Private Branch Exchange (PBX) |
Use Scenario: Routing audio codec signals between baseband processor and multiple handset/headset interfaces in VoIP phones. IC Role / Device Role / Timing Role: Dual 1-bit switch managing analog audio paths and digital control lines (e.g., headset detect, button press) with independent enable control. Use Value: Independent 1OE/2OE pins allow simultaneous or staggered path activation; 3 Ω ron avoids audible attenuation in 20 Hz–20 kHz voice band. |
Use Scenario: Isolating TDM time-slot data between DSP and multiple line interface units (LIUs) in carrier-grade PBX chassis. IC Role / Device Role / Timing Role: High-bandwidth bus switch enabling dynamic reconfiguration of PCM highway slots without introducing jitter or skew. Use Value: 500 MHz bandwidth supports multi-GHz TDM clock harmonics; flat ron ensures consistent amplitude across all 128 time slots. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bus switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74CB3Q3244PWR | Octal non-inverting bus switch (8-bit), higher channel count but no independent OE per pair; ron = 4 Ω typical. | Suitable for wide-data-bus isolation (e.g., memory expansion), not optimal for dual independent signal routing. | Select when consolidating multiple 74CB3Q3305DCURE4 functions onto one IC - requires PCB redesign due to TSSOP-20 footprint and different pinout. |
| 74LVC1G3157DP,125 | Single SPDT analog switch, 5-V tolerant, ron = 5 Ω typical, no charge pump - higher ron variation vs. voltage. | Applicable for single-path selection (e.g., sensor multiplexing), lacks dual independent control and 500 MHz bandwidth. | Choose for cost-sensitive, low-pin-count designs where 0.15 ns delay and flat ron are non-critical - uses smaller XSON-6 package. |
Compared with SN74CB3Q3244PWR and 74LVC1G3157DP,125, the 74CB3Q3305DCURE4 uniquely delivers dual independent OE control, 3 Ω flat ron, and 500 MHz bandwidth in an 8-pin VSSOP - making it irreplaceable for applications requiring precise, low-distortion, asynchronous dual-channel signal routing in optical and USB infrastructure.
Availability
74CB3Q3305DCURE4 is available at Aetrix Electronics and suitable for optical networking, USB interface isolation, and IP phone audio routing requiring stable component supply across extended product lifecycles.
Supply support for 74CB3Q3305DCURE4 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with over 90 years of innovation in high-reliability signal conditioning and interface solutions.
The CB3Q family - including the 74CB3Q3305DCURE4 - was designed specifically for high-bandwidth, low-distortion signal routing in broadband communications, optical transport, and data-intensive computing systems where rail-to-rail analog switching and 5-V tolerance are mandatory.
FAQ
What is the maximum operating frequency supported by the 74CB3Q3305DCURE4?
The 74CB3Q3305DCURE4 supports a high-bandwidth data path up to 500 MHz, as confirmed in the TI datasheet SCDS141C. This applies to small-signal AC performance under recommended conditions (VCC = 3.3 V, TA = 25°C). Real-world usable frequency depends on layout parasitics and load capacitance - the 0.15 ns propagation delay and 3.5 pF OFF-state capacitance make it suitable for 480 Mbps USB 2.0 and EPON 1.25 Gbps burst-mode applications. The 74CB3Q3305DCURE4 does not specify a guaranteed minimum frequency.
Does the 74CB3Q3305DCURE4 support partial power-down operation?
Yes, the 74CB3Q3305DCURE4 fully supports partial-power-down via its IOFF circuitry. When VCC = 0 V, the device blocks current backflow from live 5-V I/Os into the unpowered section, limiting IOFF to 1 µA maximum. This feature is explicitly validated in the datasheet's Electrical Characteristics table and enables safe hot-swap operation in optical modules and modular PBX systems - a key differentiator from standard CMOS switches.
What is the ON-state resistance (ron) specification for the 74CB3Q3305DCURE4?
The 74CB3Q3305DCURE4 has a typical ON-state resistance of 3 Ω, measured at VCC = 3.3 V, IO = 30 mA, and TA = 25°C. This value remains flat across the full operating voltage (2.3–3.6 V) and temperature (–40°C to +85°C) ranges due to its integrated charge pump. The datasheet specifies ron ≤ 8 Ω maximum under worst-case conditions - critical for minimizing insertion loss in high-speed data paths routed through the 74CB3Q3305DCURE4.
Can the 74CB3Q3305DCURE4 interface between 3.3-V and 5-V systems?
Yes, the 74CB3Q3305DCURE4 provides true 5-V tolerant I/Os - meaning its A/B ports accept 0–5.5 V signals regardless of whether VCC is powered (2.3–3.6 V) or unpowered (0 V). This capability is explicitly tested and guaranteed per the Absolute Maximum Ratings and Recommended Operating Conditions tables in the TI datasheet. It eliminates external level shifters in mixed-voltage designs such as USB 2.0 PHY interfacing or EPON optical driver control - a core function of the 74CB3Q3305DCURE4.
What package type is used for the 74CB3Q3305DCURE4?
The 74CB3Q3305DCURE4 uses the VSSOP-8 package (package drawing DCU), with nominal body dimensions of 2.00 mm × 3.10 mm and 0.5-mm lead pitch. This ultra-thin, space-efficient package is optimized for high-density applications like optical transceivers and compact IP phone PCBs. Pin 1 identification is marked in the top-left corner per JEDEC MO-178 standards, and the device is RoHS-compliant with green (Pb-free, Sb/Br-free) finish per TI's packaging addendum.
74CB3Q3305DCURE4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74CB
- Package/Case:
- 8-VFSOP (0.091", 2.30mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Bus Switch
- Circuit:
- 1 x 1:1
- Independent Circuits:
- 2
- 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:
- 8-VSSOP
74CB3Q3305DCURE4 FAQ
1.How can I place an order for 74CB3Q3305DCURE4 through Aetrix?
Please submit a Request for Quotation (RFQ) for 74CB3Q3305DCURE4 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 74CB3Q3305DCURE4 reliable?
The price and inventory of 74CB3Q3305DCURE4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74CB3Q3305DCURE4 is usually 5 days.
3.What payment methods are accepted for 74CB3Q3305DCURE4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74CB3Q3305DCURE4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 74CB3Q3305DCURE4?
74CB3Q3305DCURE4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 74CB3Q3305DCURE4 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 74CB3Q3305DCURE4?
For technical support, including 74CB3Q3305DCURE4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74CB3Q3305DCURE4 requirements.
6.How does Aetrix verify that 74CB3Q3305DCURE4 is sourced from the original manufacturer or authorized distributors?
All 74CB3Q3305DCURE4 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 74CB3Q3305DCURE4 meets industry standards.
7.What is the process for return or replacement of 74CB3Q3305DCURE4?
All 74CB3Q3305DCURE4 units undergo pre-shipment inspection (PSI). If there is an issue with 74CB3Q3305DCURE4, 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 74CB3Q3305DCURE4 part is unused and in its original packaging.
Return procedure for 74CB3Q3305DCURE4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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