SN74LVC1T45DCKR

Texas Instruments SN74LVC1T45DCKR – 1‑Bit Dual‑Supply, Direction‑Controlled Level Translator in SC70‑6 (DCK)

The Texas Instruments SN74LVC1T45DCKR is a compact, single‑bit level translator built for clean, direction‑controlled logic translation between low‑voltage and 5‑V domains. With dual supplies ranging from 1.65 V to 5.5 V on both sides, a DIR control input, push‑pull three‑state outputs, and Ioff support for partial‑power‑down, it’s a reliable choice for interfacing MCUs, MPUs, FPGAs, and peripherals that operate at different logic levels. Packaged in a tiny SC70‑6 (DCK) and supplied as Tape & Reel (DCKR), it’s well suited to high‑density, space‑constrained designs.

Highlights at a Glance

• Brand/manufacturer: Texas Instruments
• MPN: SN74LVC1T45DCKR (LVC1T series)
• Category: Logic Level Translators
• Function: 1‑bit, dual‑supply, direction‑controlled voltage‑level translator
• I/O type: Push‑pull, three‑state outputs
• Supply ranges: VCCA = 1.65 V to 5.5 V, VCCB = 1.65 V to 5.5 V
• Direction control: DIR pin (not auto‑bidirectional)
• Partial power‑down: Ioff supported
• Package: SC70‑6 (DCK), Tape & Reel (DCKR), surface mount
• Pin count: 6
• Lifecycle: Active
• RoHS status: RoHS compliant; lead‑free, Green

What Makes the SN74LVC1T45DCKR Stand Out

When your design spans multiple logic domains—such as 1.8 V microcontrollers interfacing with 3.3 V sensors, or 3.3 V FPGAs talking to 5 V peripherals—the SN74LVC1T45DCKR offers a straightforward, robust solution. Its dual‑supply architecture allows either side (A or B) to operate anywhere from 1.65 V to 5.5 V, enabling translation up or down within that range. Because it is direction‑controlled via the DIR pin, signals are translated deterministically in the chosen direction without the ambiguity that can arise in auto‑sensing translators.

Engineers will appreciate the push‑pull drive and three‑state output capability for clean edges and easy bus isolation, while sourcing managers will value the device’s active lifecycle status, RoHS compliance, and broad applicability across product lines. The SC70‑6 (DCK) package helps achieve high density on PCBs where every square millimeter matters.

Specifications

Core Electrical and Functional Characteristics

• Channels: 1
• Logic family: LVC1T
• Direction: Bidirectional with DIR pin (direction‑controlled)
• I/O type: Push‑pull, three‑state outputs
• Voltage range (VCCA): 1.65 V to 5.5 V
• Voltage range (VCCB): 1.65 V to 5.5 V
• Partial power‑down: Ioff supported (outputs remain off when supply is 0 V)

Mechanical and Packaging

• Package: SC70‑6 (DCK)
• Tape & Reel designator: DCKR
• Mounting type: Surface Mount
• Pin count: 6

Environmental

• Operating temperature range: −40°C to +85°C
• RoHS/Green: Pb‑Free (RoHS), Green device

Not Specified Here

• Timing parameters (such as propagation delay), maximum data rates, current drive levels, and precise electrical limits beyond the ranges above are not specified in this summary. Refer to the Texas Instruments datasheet for full electrical characteristics.

Typical Applications

• General‑purpose logic level shifting between low‑voltage and 5‑V systems
• Interfacing MCUs/MPUs and FPGAs with peripherals operating at different logic levels
• GPIO expansion and digital signaling across mixed‑voltage domains
• Memory card and sensor interface level translation for push‑pull signals

These scenarios commonly appear in industrial control, consumer electronics, instrumentation, and embedded platforms where signals must traverse multiple power domains without compromising logic thresholds or signal integrity.

Design‑In Guidance and Best Practices

Implementing the SN74LVC1T45DCKR is straightforward, but a few practical considerations help ensure first‑pass success:

• Use the DIR pin intentionally. This device is bidirectional but not auto‑sensing. The DIR input sets the active data direction. Plan your control logic so that DIR is stable whenever the bus is actively switching.
• Confirm push‑pull signaling. The part is designed for push‑pull digital signals. It is not a drop‑in for open‑drain buses such as I2C. For open‑drain translation, a dedicated translator (for example, a device like TI’s PCA9306 family) is recommended.
• Leverage three‑state outputs. The three‑state capability helps isolate buses and avoid contention when multiple devices share a line. Coordinate OE or system‑level enable controls accordingly if applicable in your topology.
• Mind mixed‑voltage rules. Both sides (VCCA and VCCB) support 1.65 V to 5.5 V. Verify that each domain stays within its intended range, and that input logic‑high/low levels are compatible with the selected supply on that side.
• Partial power‑down behavior. With Ioff support, outputs are effectively disabled when supply is 0 V, aiding hot‑swap and power‑sequencing scenarios. Still, implement sound power‑domain sequencing practices to minimize inrush and undefined states elsewhere in the system.
• Decoupling and layout. Place appropriate local decoupling capacitors close to each supply pin per TI’s general recommendations. Keep traces short and direct on high‑speed or sensitive lines and follow standard signal‑integrity layout practices.
• Validate direction changes in firmware. If your firmware changes DIR dynamically, ensure that bus lines are idle or tri‑stated during direction hand‑offs to prevent contention.

Note: Numeric limits (such as current drive, edge rates, or timing) should be taken from the official datasheet to finalize margins for your application.

Why Direction‑Controlled Translation Matters

Auto‑bidirectional translators are convenient for certain open‑drain or low‑speed applications, but they can introduce uncertainty when two actively driven push‑pull devices might attempt to drive the same line. The Texas Instruments SN74LVC1T45DCKR avoids this ambiguity with a definitive DIR control. That makes it well suited to interfaces where signaling direction is known or managed by the system, such as uni‑directional data paths, multiplexed control signals, or shared lines where direction changes are orchestrated by firmware.

In addition, push‑pull drivers help achieve clean logic transitions and resilient interfacing in noisy environments, while the three‑state feature improves bus sharing and isolation strategies.

Lifecycle, Availability, and Sourcing Considerations

• Lifecycle status: Active (per Texas Instruments product information)
• Packaging: SC70‑6 (DCK) with Tape & Reel designation DCKR
• RoHS/Green: RoHS compliant; lead‑free, Green device
• Global use: Suitable for worldwide deployment where RoHS compliance is required

For pricing and stock, check authorized distributors or the Texas Instruments product page. Lead times and availability may vary by region and demand. If your build plan requires second sources or alternates, the functionally similar devices below can be a starting point. Always verify compatibility details before substitution.

Approved Alternates and Cross‑References

• 74AVC1T45 — Functionally similar 1‑bit level translator (available from various manufacturers). Validate pinout, supply ranges, and timing.
• SN74AVC1T45 — Similar TI device family; confirm electrical and timing characteristics.

Policy note: Before substitution, verify pinout, voltage ranges, timing, and direction‑control behavior against your requirements and PCB footprint.

At the time of writing, no direct drop‑in replacements are specified for the SN74LVC1T45DCKR beyond the general alternates above.

Compliance and Environmental

• RoHS compliance: Yes; Pb‑Free (lead‑free), Green
• Partial power‑down: Ioff support
• Operating temperature: −40°C to +85°C

If additional compliance documentation is required for your product file (e.g., material declarations or environmental certificates), consult the TI product page or request compliance documents through your authorized distributor.

Procurement Tips for Buyers and Sourcing Teams

• Confirm the exact ordering code “SN74LVC1T45DCKR” to receive Tape & Reel in the SC70‑6 (DCK) package. TI’s suffixes denote package and packing; “DCKR” indicates SC70‑6 in reel format.
• Evaluate long‑term availability on TI’s product page and via franchised distribution to align with lifecycle and volume plans.
• For AVL/AML creation, include voltage range notes (VCCA and VCCB each 1.65 V to 5.5 V), direction‑controlled behavior (DIR pin), and Ioff partial power‑down support.
• Keep an approved alternate on file (e.g., SN74AVC1T45 or 74AVC1T45) with clear engineering sign‑off that pinouts and key electrical behavior match your use case.

Frequently Asked Questions (FAQs)

Q: Is the SN74LVC1T45 auto‑bidirectional?
A: No. It is bidirectional but requires the DIR pin to set the data direction.

Q: Can it be used for I2C level shifting?
A: It is not recommended for open‑drain, auto‑bidirectional buses like I2C. Use a dedicated I2C translator (e.g., a device such as PCA9306) for that application.

Q: What supply voltages does it support?
A: Both VCCA and VCCB operate from 1.65 V to 5.5 V, allowing translation in either direction within those ranges.

Q: How many channels does it provide?
A: It is a single‑channel (1‑bit) translator.

Q: What package is the SN74LVC1T45DCKR supplied in?
A: SC70‑6 (DCK) package, supplied in Tape & Reel (DCKR). It is intended for surface‑mount assembly.

Q: Does it support partial power‑down?
A: Yes. It supports Ioff, which disables outputs when the supply is 0 V, aiding partial‑power‑down and hot‑plug scenarios.

Q: Is the device RoHS compliant?
A: Yes. It is specified as Pb‑Free (RoHS), Green.

Resources

• Texas Instruments Product Page: https://www.ti.com/product/SN74LVC1T45
• Datasheet (SN74LVC1T45): https://www.ti.com/lit/ds/symlink/sn74lvc1t45.pdf

For the most accurate and complete electrical specifications, design notes, and application guidance, always refer to the official TI datasheet and product documentation.