Texas Instruments SN74LVC861ADGVR

Overview

SN74LVC861ADGVR from Texas Instruments is a 10-bit bus transceiver with 3-state outputs, designed for bidirectional asynchronous data transfer between A and B buses in 1.65-V to 3.6-V systems. It features dual output-enable controls (OEAB/OEBA), supports mixed-mode 3.3-V/5-V I/O, and delivers 6.4 ns max propagation delay at 3.3 V - enabling use in level-shifting interfaces for industrial control backplanes and FPGA-to-ASIC interconnects.

For engineers reviewing the SN74LVC861ADGVR datasheet, SN74LVC861ADGVR pinout, SN74LVC861ADGVR application, or SN74LVC861ADGVR equivalent, key selection criteria include its Ioff partial-power-down capability, 5.5-V-tolerant inputs, ±24-mA drive strength at 3 V, and TVSOP-24 package compatibility with high-density PCB layouts.

Technical Context

The SN74LVC861ADGVR implements dual independent direction-control logic: OEAB enables A→B transmission while OEBA enables B→A, allowing dynamic bus arbitration without external logic. Its LVC-family CMOS process ensures rail-to-rail input voltage tolerance (0–5.5 V) and low-noise switching performance, including <0.8 V typical ground bounce (VOLP) and >2 V typical VOH undershoot (VOHV) at 3.3 V.

Designed for partial-power-down operation, the device integrates Ioff circuitry that disables outputs and blocks current backflow when VCC = 0 V - critical for hot-swap and power-gated subsystems. All 20 I/O pins (A1–A10, B1–B10) and two enables (OEAB, OEBA) are fully specified across –40°C to 85°C, with latch-up immunity exceeding 250 mA per JESD 17.

Key Specifications

Pinout & Package

SN74LVC861ADGVR uses a 24-pin TVSOP (Thin Very Small Outline Package) with 0.4-mm lead pitch, 6.6-mm × 4.4-mm body, and 1.2-mm maximum height - optimized for space-constrained PCBs requiring fine-pitch assembly and thermal efficiency.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus transceiver applications.

Compared with SN74LVC861APWR and SN74LVC861ADBR, the SN74LVC861ADGVR offers the smallest PCB footprint and lowest profile (1.2 mm max height), making it optimal for ultra-thin industrial HMIs and portable test instrumentation where Z-axis space is constrained.

Availability

SN74LVC861ADGVR is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA-to-ASIC bridges, automotive body control modules, test equipment signal conditioning, and mixed-voltage embedded subsystems requiring stable component supply and long-term manufacturability.

Supply support for SN74LVC861ADGVR 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 logic solutions, with decades of expertise in high-reliability interface ICs and power management.

The SN74LVC861ADGVR belongs to TI's LVC logic family, engineered for low-voltage, high-speed bidirectional bus communication in mixed-signal systems where voltage translation, power sequencing resilience, and space efficiency are critical.

FAQ

What is the maximum operating frequency supported by the SN74LVC861ADGVR?

The SN74LVC861ADGVR does not specify a maximum clock frequency directly, but its 6.4 ns maximum propagation delay at 3.3 V implies reliable operation up to approximately 100 MHz for single-cycle data transfers. System-level timing depends on bus loading, trace impedance, and OE control synchronization - actual achievable rate must be validated using worst-case tpd, ten, and tdis values from the datasheet under target VCC and temperature conditions. The SN74LVC861ADGVR is intended for asynchronous bus control, not synchronous clocked operation.

Can the SN74LVC861ADGVR safely interface a 5-V microcontroller with a 1.8-V FPGA?

Yes, the SN74LVC861ADGVR supports this mixed-voltage interface: its inputs tolerate 0–5.5 V regardless of VCC, and its outputs swing rail-to-rail between GND and VCC. When powered at 1.8 V, the SN74LVC861ADGVR accepts 5-V inputs without damage and drives the FPGA with 0–1.8-V logic levels. Ensure OEAB/OEBA are driven within the 1.8-V domain and that the 5-V microcontroller's output current limits are not exceeded - the SN74LVC861ADGVR presents ~5 pF input capacitance per control pin.

How should unused input pins be handled on the SN74LVC861ADGVR?

All unused inputs on the SN74LVC861ADGVR - including A1–A10, B1–B10, OEAB, and OEBA - must be tied to either VCC or GND to prevent floating nodes that cause increased ICC, noise susceptibility, or erratic output states. TI recommends using pullup or pulldown resistors (e.g., 10 kΩ) rather than direct connection to minimize board-level ESD risk. Leaving any input unconnected violates recommended operating conditions and may result in undefined behavior or accelerated device wear.

Does the SN74LVC861ADGVR support hot-swap operation?

Yes, the SN74LVC861ADGVR supports hot-swap via its Ioff feature: when VCC = 0 V, the Ioff circuitry disables all outputs and limits leakage to ±10 µA even with 5.5-V signals applied to I/O pins. This prevents back-driving powered-down sections of the system. However, hot-swap reliability also depends on external circuitry - ensure power sequencing controls VCC ramp rate and that bus stubs are terminated to avoid reflections during insertion. The SN74LVC861ADGVR itself meets JESD 17 latch-up immunity (>250 mA), enhancing robustness during transient events.

What is the thermal resistance (θJA) of the SN74LVC861ADGVR in its TVSOP package?

The SN74LVC861ADGVR in the TVSOP (DGV) package has a junction-to-ambient thermal resistance (θJA) of 86°C/W, measured under standard JEDEC JESD 51-7 conditions (single-layer 1-in² copper pad, no airflow). This value assumes proper PCB layout with adequate copper pour under the exposed pad (if present) and thermal vias. In compact, multi-layer boards with enhanced thermal dissipation, actual θJA may improve by 10–20%; in enclosed, still-air environments, it may degrade. The SN74LVC861ADGVR's low ICC (<10 µA) minimizes self-heating under static conditions.