Texas Instruments SN74AVC20T245DGGR

Overview

SN74AVC20T245DGGR from Texas Instruments is a 20-bit dual-supply noninverting bus transceiver enabling bidirectional voltage-level translation between 1.2-V to 3.6-V domains. It features independent A and B ports tracking VCCA and VCCB, I_off partial-power-down support, VCC isolation, and 4.6-V tolerant I/Os. Used in mixed-voltage FPGA-to-ASIC interconnects, memory subsystems, and low-power portable SoC interfaces.

For engineers reviewing the SN74AVC20T245DGGR datasheet, SN74AVC20T245DGGR pinout, SN74AVC20T245DGGR application, or SN74AVC20T245DGGR equivalent, key selection criteria include dual-rail supply flexibility (1.2–3.6 V per rail), 380 Mbps max data rate (1.8 V → 3.3 V), high-impedance control via 1OE/2OE, and TSSOP-56 thermal performance (θ_JA = 64°C/W).

Technical Context

The SN74AVC20T245DGGR implements two independent 10-bit transceiver sections, each with dedicated DIR and OE controls referenced to VCCA. Directional data flow (A↔B) is determined per-section by logic level on 1DIR/2DIR, while 1OE/2OE independently disable outputs into high-impedance state.

VCC isolation ensures both ports enter high-Z if either VCCA or VCCB is at GND. Control inputs tolerate overvoltage up to 4.6 V regardless of rail voltage, and I_off circuitry prevents backflow current during power-down, supporting hot-insertion and partial-power-down system architectures.

Key Specifications

Pinout & Package

TSSOP-56 package (DGG), 12.0 mm × 6.1 mm × 1.2 mm body, 0.5-mm pitch, exposed metal pad not present, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AVCH16T245DGVR and SN74LVC20T245DGGR, the SN74AVC20T245DGGR uniquely supports full 1.2–3.6-V dual-rail operation with VCC isolation and 380 Mbps throughput - making it the sole option for next-gen low-power mixed-voltage SoC interconnects requiring guaranteed high-Z fail-safe behavior.

Availability

SN74AVC20T245DGGR is available at Aetrix Electronics and suitable for DDR memory interface bridging, FPGA-to-microcontroller interconnect, and portable SoC power domain isolation requiring stable component supply across industrial, automotive, and medical electronics programs.

Supply support for SN74AVC20T245DGGR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and consumer markets.

The SN74AVC20T245DGGR belongs to TI's AVC advanced very-low-voltage CMOS logic family, engineered specifically for robust bidirectional voltage translation in heterogeneous power-domain systems with strict power sequencing and ESD resilience requirements.

FAQ

What is the minimum operating voltage for SN74AVC20T245DGGR on VCCA and VCCB rails?

The SN74AVC20T245DGGR operates down to 1.2 V on both VCCA and VCCB rails, with full functionality including I_off, VCC isolation, and 4.6-V I/O tolerance maintained across the entire 1.2–3.6-V range. Below 1.2 V, timing parameters and drive strength are not characterized, and operation is not guaranteed.

Does SN74AVC20T245DGGR support hot-swapping between powered and unpowered voltage domains?

Yes, the SN74AVC20T245DGGR supports hot-swapping via its I_off feature and VCC isolation. When either VCCA or VCCB is at GND or floating, the corresponding port enters high-impedance state, preventing backdrive current. I_off leakage remains below ±0.1 µA, ensuring safe insertion into live backplanes.

Can SN74AVC20T245DGGR translate between 1.2-V and 3.3-V logic without external components?

Yes, the SN74AVC20T245DGGR performs direct 1.2-V ↔ 3.3-V translation with no external resistors or biasing. Its fully configurable dual-rail architecture allows VCCA = 1.2 V and VCCB = 3.3 V simultaneously, and its 4.6-V tolerant I/Os safely handle the voltage differential without clamping diodes or level-shifting circuitry.

What is the thermal resistance (θ_JA) of SN74AVC20T245DGGR in its TSSOP-56 package?

The SN74AVC20T245DGGR in the DGG (TSSOP-56) package has a junction-to-ambient thermal resistance (θ_JA) of 64°C/W under standard JEDEC test conditions (1-layer board, 1-in² copper). This value assumes no internal thermal vias or enhanced PCB copper; actual performance improves with 2+ oz copper and thermal pads.

How does the VCC isolation feature behave during power-up sequencing of SN74AVC20T245DGGR?

During power-up, the VCC isolation feature ensures both A and B ports remain in high-impedance state until both VCCA and VCCB exceed ~1.0 V. This prevents bus contention if one rail powers up significantly before the other. OE pins should be held high (via pullup to VCCA) during sequencing to guarantee deterministic isolation prior to valid control signals.