Texas Instruments SN74AVCH8T245DGVR

Overview

SN74AVCH8T245 from Texas Instruments is an 8-bit dual-supply noninverting bus transceiver enabling bidirectional voltage translation between 1.2V–3.6V domains (e.g., A port at 1.8V ↔ B port at 3.3V), with configurable direction control (DIR), 3-state output enable (OE), and bus-hold on all data I/Os. It supports up to 320Mbps data rate when both supplies ≥1.8V and features VCC isolation, Ioff partial-power-down, and 4.6V I/O tolerance.

For engineers reviewing the SN74AVCH8T245 datasheet, SN74AVCH8T245 pinout, SN74AVCH8T245 application, or SN74AVCH8T245 equivalent, key selection criteria include dual-rail supply flexibility (VCCA/VCCB = 1.2–3.6V), guaranteed 3.1ns typical propagation delay (A→B, VCCA=1.2V/VCCB=1.2V), bus-hold elimination of external resistors, and compatibility with industrial temperature range (–40°C to +85°C).

Technical Context

The SN74AVCH8T245 implements a fully configurable dual-rail architecture where DIR and OE inputs are referenced exclusively to VCCA, while A-port I/Os track VCCA and B-port I/Os track VCCB - enabling asymmetric voltage translation without level-shifter biasing. Its bus-hold circuitry actively sustains logic states (IBHL ≥25μA low, IBHH ≥–25μA high at 1.2V) and eliminates floating inputs.

VCC isolation ensures outputs enter high-impedance when either VCCA or VCCB = GND, and Ioff limits power-off leakage to ±5μA per port. The device meets JESD 78 Class II latch-up immunity (>100mA) and exceeds JESD 22 ESD ratings: ±8kV HBM, ±200V MM, ±1kV CDM.

Key Specifications

Pinout & Package

SN74AVCH8T245DGVR uses the DGV package: 24-pin TVSOP (5.0mm × 6.4mm), 0.4mm pitch, exposed pad not present. Pin 1 = VCCA; pins 11/12/13 = GND; pins 23/24 = VCCB; pin 2 = DIR (VCCA-referenced); pin 22 = OE (VCCA-referenced); pins 3–10 = A1–A8 (VCCA-referenced); pins 14–21 = B8–B1 (VCCB-referenced, reverse order).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC8T245PW and TXB0108PWR, the SN74AVCH8T245 provides unique dual-supply independence, VCC isolation for robust power sequencing, and guaranteed 320Mbps performance - making it irreplaceable in mixed-voltage industrial and telecom infrastructure where reliability and timing predictability are mandatory.

Availability

SN74AVCH8T245DGVR is available at Aetrix Electronics and suitable for industrial automation, enterprise storage, telecommunications infrastructure, and automotive ADAS sensor hub designs requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SN74AVCH8T245DGVR 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 electronic components.

The SN74AVCH8T245 belongs to TI's AVC logic family, engineered specifically for low-voltage, high-speed bidirectional translation in mixed-supply systems - targeting industrial, telecom, and computing applications demanding robust power sequencing and ESD resilience.

FAQ

What voltage ranges are supported by SN74AVCH8T245DGVR on its A and B ports?

The SN74AVCH8T245DGVR supports independent supply voltages from 1.2V to 3.6V on both VCCA (A port) and VCCB (B port). This enables translation between any combination of 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V logic domains without external components. The control inputs DIR and OE are referenced solely to VCCA, not VCCB.

How does SN74AVCH8T245DGVR handle power sequencing when VCCA and VCCB are powered up at different times?

The SN74AVCH8T245DGVR implements VCC isolation: if either VCCA or VCCB is at GND while the other is powered, all outputs automatically enter high-impedance state. This prevents bus contention and backdrive damage. Bus-hold circuitry remains active on the powered side, maintaining valid logic states on undriven inputs.

Can SN74AVCH8T245DGVR replace older 74-series transceivers like SN74LS245 in existing designs?

No - the SN74AVCH8T245DGVR is not a drop-in replacement for bipolar 74LS245 due to fundamental differences: it is CMOS-based, requires dual supplies (not single 5V), has different pinout (e.g., DIR/OE referenced to VCCA), and operates down to 1.2V. Migration requires PCB layout and power delivery redesign, but delivers superior speed, power efficiency, and voltage flexibility.

What is the maximum guaranteed data rate for SN74AVCH8T245DGVR under worst-case supply conditions?

The SN74AVCH8T245DGVR guarantees 170Mbps maximum data rate when either VCCA ≤1.8V or VCCB ≤1.8V (e.g., VCCA=1.2V/VCCB=3.3V). At this condition, propagation delay remains ≤6.8ns (A→B, VCCA=1.5V/VCCB=3.3V), and timing margins hold across –40°C to +85°C ambient.

Does SN74AVCH8T245DGVR require external pullup resistors on DIR or OE pins?

No - external pullups are unnecessary. The SN74AVCH8T245DGVR has no internal weak pullups on DIR or OE. However, to ensure defined state during power-up, OE should be tied to VCCA via a pullup resistor (value determined by driver sink capability), and DIR must be actively driven or held by system logic - bus-hold applies only to A/B data pins, not control inputs.