Texas Instruments 74AVCH4T245PWRG4

Overview

74AVCH4T245PWRG4 from Texas Instruments is a 4-bit dual-supply bus transceiver enabling bidirectional voltage-level translation between 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V domains. It features independent VCCA (1.2–3.6V) and VCCB (1.2–3.6V) rails, 4.6V I/O tolerance, bus-hold circuitry, and Ioff for partial power-down operation. It supports up to 380Mbps data rate in 1.8V→3.3V translation and is used in mixed-voltage interconnects between processors and peripherals.

For engineers reviewing the 74AVCH4T245PWRG4 datasheet, 74AVCH4T245PWRG4 pinout, 74AVCH4T245PWRG4 application, or 74AVCH4T245PWRG4 equivalent, key selection criteria include configurable dual-rail operation, 3-state output control via DIR/OE pins referenced to VCCA, Ioff-enabled isolation during power sequencing, bus-hold elimination of external resistors, and TSSOP-16 package compatibility with high-density PCB layouts.

Technical Context

The 74AVCH4T245PWRG4 implements a fully asynchronous, direction-controlled bidirectional translation architecture: DIR input selects data flow direction (A→B or B→A), while OE enables/disables outputs into high-impedance state. All control inputs (1DIR, 2DIR, 1OE, 2OE) are referenced to VCCA, ensuring consistent logic thresholds regardless of VCCB level.

VCC isolation ensures both ports enter high-impedance when either VCCA or VCCB falls below ~0.4V, preventing false signaling. Bus-hold circuitry actively maintains valid logic states on undriven A/B port inputs without external biasing, and Ioff limits reverse current during partial power-down-critical for hot-swap and multi-rail system reliability.

Key Specifications

Pinout & Package

TSSOP-16 (PW) package: 5mm × 6.4mm body, 0.65mm pitch, surface-mount, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC4T245PWR and TXB0104RGYR, the 74AVCH4T245PWRG4 uniquely combines 1.2V operation, bus-hold, Ioff, VCC isolation, and 380Mbps capability-making it the only choice for robust, high-speed, ultra-low-voltage mixed-domain interconnects requiring minimal external components.

Availability

74AVCH4T245PWRG4 is available at Aetrix Electronics and suitable for mobile processor interfacing, FPGA-to-ASIC communication, and industrial sensor hub applications requiring stable component supply, long-term lifecycle assurance, and full traceability.

Supply support for 74AVCH4T245PWRG4 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 and embedded processing solutions, with over 90 years of innovation in precision analog, power management, and logic devices.

The SN74AVCH4T245 belongs to TI's AVC logic family-designed specifically for low-voltage, high-speed bidirectional level translation in space-constrained, multi-rail systems such as portable electronics, industrial controllers, and automotive infotainment platforms.

FAQ

What voltage ranges does the 74AVCH4T245PWRG4 support on its A and B ports?

The 74AVCH4T245PWRG4 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. The 74AVCH4T245PWRG4 datasheet specifies absolute maximum ratings up to 4.6V on I/O pins, but recommended operating conditions strictly limit VCCA and VCCB to 1.2–3.6V for reliable functionality.

How does the 74AVCH4T245PWRG4 handle power sequencing when VCCA and VCCB ramp at different times?

The 74AVCH4T245PWRG4 incorporates VCC isolation: if either VCCA or VCCB falls below ~0.4V, both A and B ports automatically enter high-impedance state, preventing bus contention. Its Ioff feature further blocks reverse current flow during partial power-down. For safe power-up, tie OE to VCCA via a pull-up resistor-ensuring outputs remain disabled until both supplies stabilize. This behavior is explicitly guaranteed in the 74AVCH4T245PWRG4 datasheet Section 7.3.5.

Does the 74AVCH4T245PWRG4 require external pull-up or pull-down resistors on its data lines?

No. The 74AVCH4T245PWRG4 integrates active bus-hold circuitry on all A- and B-port I/Os, which maintains valid logic states on undriven or floating inputs without external resistors. TI explicitly advises against using pull-up/pull-down resistors with bus-hold enabled, as they conflict with the internal sustaining current (IBHL/IBHH). This feature is confirmed in the 74AVCH4T245PWRG4 datasheet Sections 1, 3, and 7.3.4.

What is the maximum data rate supported by the 74AVCH4T245PWRG4, and under what conditions?

The 74AVCH4T245PWRG4 supports up to 380Mbps when translating from 1.8V to 3.3V (VCCA = 1.8V, VCCB = 3.3V), as specified in the "Features" section and validated in switching characteristics tables (Section 5.8). Lower rates apply for other combinations: 200Mbps for <1.8V→3.3V or translation to 2.5V/1.8V, 150Mbps to 1.5V, and 100Mbps to 1.2V. These values reflect guaranteed performance across –40°C to +85°C.

Is the 74AVCH4T245PWRG4 pin-compatible with other 4-bit transceivers like the SN74LVC4T245?

No. While both are 16-pin TSSOP bus transceivers, the 74AVCH4T245PWRG4 has distinct pin mapping: VCCA is on pin 1, VCCB on pin 16, and GND on pins 8 and 9-whereas SN74LVC4T245 places VCC on pin 1 and GND on pin 16. Additionally, the 74AVCH4T245PWRG4 uses VCCA-referenced DIR/OE inputs and supports 1.2V operation, unlike LVC's 1.65V minimum. Direct replacement would require PCB redesign.