Texas Instruments SN74AVCH20T245VR

Overview

SN74AVCH20T245VR 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 VCCA and VCCB rails, bus-hold on all data inputs, Ioff partial-power-down support, and 4.6-V tolerant I/Os. Used in mixed-voltage SoC interconnects, FPGA-to-ASIC interfaces, and low-power embedded memory buses.

For engineers reviewing the SN74AVCH20T245VR datasheet, SN74AVCH20T245VR pinout, SN74AVCH20T245VR application, or SN74AVCH20T245VR equivalent, key selection criteria include its 56-pin TVSOP (DGV) package, 100–380 Mbps data rate scalability across voltage combinations, VCC isolation behavior, and bus-hold elimination of external resistors.

Technical Context

The SN74AVCH20T245VR implements two independent 10-bit transceiver sections (1A↔1B and 2A↔2B), each with dedicated DIR and OE controls referenced to VCCA. Its dual-rail architecture allows simultaneous operation at different supply voltages - e.g., VCCA = 1.8 V for core logic and VCCB = 3.3 V for legacy peripherals.

VCC isolation ensures both ports enter high-impedance when either VCCA or VCCB is at GND. The Ioff circuitry actively disables outputs during power-down to prevent back-current flow, while bus-hold circuits maintain valid logic states on undriven inputs without external components.

Key Specifications

Pinout & Package

SN74AVCH20T245VR uses a 56-pin Thin Very Small Outline Package (TVSOP, DGV), 7.7 mm × 4.4 mm × 1.2 mm, with 0.4-mm lead pitch and exposed thermal pad. Pin 1 marked via top-side "WK245" laser etch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AVCH16T245DGGR, SN74AVCH20T245VR provides 20-bit width and TVSOP packaging for higher-density routing; versus TXB0108PWR, it offers deterministic direction control, higher drive, and full bus-hold - critical for noise-sensitive or high-speed parallel buses.

Availability

SN74AVCH20T245VR is available at Aetrix Electronics and suitable for industrial automation interfaces, automotive infotainment subsystems, and portable electronics requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74AVCH20T245VR 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 personal electronics markets.

The SN74AVCH20T245VR belongs to TI's AVC (Advanced Very-Low-Voltage CMOS) logic family, engineered for ultra-low-voltage bidirectional translation in power-sensitive, multi-rail digital systems.

FAQ

What is the maximum allowable voltage on SN74AVCH20T245VR I/O pins when VCCA = 1.2 V?

The SN74AVCH20T245VR guarantees 4.6-V tolerance on all A- and B-side I/O pins regardless of VCCA or VCCB setting. This allows safe connection to 3.3-V or 5-V systems even when operating at minimum 1.2-V supply - a key enabler for mixed-voltage board design without external clamping.

Does SN74AVCH20T245VR require external pullup or pulldown resistors on data lines?

No. The SN74AVCH20T245VR integrates bus-hold circuitry on all 20 data inputs, actively maintaining valid logic states without external resistors. Using pull resistors alongside bus-hold is explicitly discouraged in the datasheet, as it may cause excessive current draw or logic instability.

How does the VCC isolation feature behave during power sequencing of SN74AVCH20T245VR?

When either VCCA or VCCB drops to GND, the SN74AVCH20T245VR forces both A- and B-side outputs into high-impedance - preventing bus contention or back-driving during asymmetric power-up/down. This behavior is hardware-enforced and requires no firmware intervention.

Can SN74AVCH20T245VR translate between 1.2-V and 1.5-V domains at 200 Mbps?

Yes. The SN74AVCH20T245VR supports 260 Mbps for sub-1.8-V translations, including 1.2-V ↔ 1.5-V. Measured propagation delay remains ≤4.1 ns under those conditions (VCCA = 1.5 V, VCCB = 1.2 V), ensuring timing closure for 200 Mbps operation with adequate margin.

What is the thermal resistance (θJA) of the SN74AVCH20T245VR in its TVSOP package?

The SN74AVCH20T245VR in the TVSOP (DGV) package has a junction-to-ambient thermal resistance (θJA) of 48°C/W, measured per JESD 51-7. This value assumes standard JEDEC 2-layer board conditions - actual performance improves with thermal vias and copper pour under the exposed pad.