STMicroelectronics 74ALVCH32245LBR

Overview

74ALVCH32245LBR from STMicroelectronics is a low-voltage CMOS 32-bit bus transceiver (3-state) with bidirectional data flow controlled by DIR inputs and output enable (nG). It operates from 1.65 V to 3.6 V, supports 3.6 V-tolerant I/O, delivers ±24 mA drive at 3.0–3.6 V, and achieves 3.0 ns max propagation delay. It is used in voltage-scalable backplane or motherboard bus interfaces between mixed-voltage domains.

For engineers reviewing the 74ALVCH32245LBR datasheet, 74ALVCH32245LBR pinout, 74ALVCH32245LBR application, or 74ALVCH32245LBR equivalent, key selection criteria include 32-bit bidirectional bus isolation, bus-hold input retention without external resistors, 3.6 V I/O tolerance in sub-3.3 V systems, and LFBGA96 package compatibility with high-density PCB layouts.

Technical Context

This IC implements eight independent 4-bit transceiver blocks (A↔B), each with dedicated DIR and nG control. Direction is asynchronous per group: when nG is LOW and DIR = LOW, A drives B; when DIR = HIGH, B drives A. All 32 I/Os feature integrated bus-hold circuitry that maintains last-valid logic state during floating conditions.

It uses C2MOS sub-micron silicon gate technology with five-layer metal interconnect. Input/output protection includes HBM ESD >2000 V and MM >200 V, plus latch-up immunity exceeding 300 mA. Power-down protection ensures safe I/O behavior during VCC ramp-up/down sequences.

Key Specifications

Pinout & Package

LFBGA96 (13.6 mm × 5.6 mm, 0.8 mm pitch) with bottom-side ball array. Package supports automated optical inspection and fine-pitch routing in space-constrained embedded systems.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 32-bit bus transceiver applications.

Compared with SN74ALVTH32245ZRGR and 74LVC32245PWJ, the 74ALVCH32245LBR uniquely combines full 3.6 V I/O tolerance, integrated bus-hold, and matched ±24 mA drive - making it optimal for dynamic, mixed-voltage, hot-pluggable bus architectures.

Availability

74ALVCH32245LBR is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive infotainment gateways, and telecom line cards requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74ALVCH32245LBR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, power management ICs, sensors, and analog/mixed-signal devices for industrial, automotive, and consumer markets.

The 74ALVCH series targets low-voltage, high-speed bus interfacing in mixed-supply systems, emphasizing robustness, I/O flexibility, and compatibility with legacy 74-series logic functions.

FAQ

Is the 74ALVCH32245LBR pin-compatible with standard 74LS32245?

No. While functionally compatible with the 74 series 32245 logic family, the 74ALVCH32245LBR uses an LFBGA96 package with different pin mapping and lacks TTL-compatible input thresholds. It is not mechanically or electrically pin-for-pin interchangeable with through-hole or SOIC-packaged 74LS variants.

Does the bus-hold feature work at 1.65 V VCC?

Yes. Bus-hold current is specified down to 1.65 V: ±25 µA at VI = 0.58 V (1.65 V case), increasing to ±75 µA at 3.0 V. The circuit remains active across the full 1.65–3.6 V operating range, retaining logic state without external biasing.

Can nG and nDIR be driven directly from a 1.8 V FPGA GPIO?

Yes. Input thresholds scale with VCC: VIH = 0.65×VCC min (1.2 V at 1.8 V VCC), and VIL = 0.35×VCC max (0.63 V). A 1.8 V FPGA output (VOH ≥ 1.62 V, VOL ≤ 0.18 V) fully satisfies these levels with margin.

What is the thermal resistance (θJA) for LFBGA96 package?

The datasheet does not specify θJA for 74ALVCH32245LBR. However, typical LFBGA96 packages with 13.6 mm × 5.6 mm footprint and internal thermal pad achieve θJA ≈ 45 °C/W with 2-layer copper pour and 4 thermal vias - sufficient for <400 mW PD at TA ≤ 85 °C.