onsemi 74LVTH32245G

Overview

74LVTH32245G from Fairchild Semiconductor is a 32-bit non-inverting bidirectional transceiver with 3-STATE outputs, bushold inputs, and dual VCC rails (VCC1 for Bytes 1–2, VCC2 for Bytes 3–4). It operates at 2.7–3.6 V, supports 5 V-tolerant I/O, delivers ±32 mA/±64 mA drive strength, and is packaged in a 96-ball FBGA (JEDEC MO-205, 5.5 mm wide) for high-density bus interfacing in telecom backplanes.

For engineers reviewing the 74LVTH32245G datasheet, pinout, applications, or equivalent options, key selection criteria include byte-level direction control (T/Rn), independent OE per byte pair, bushold input retention without external pull-ups, 3.3 V core compatibility with 5 V I/O tolerance, and FBGA thermal/mechanical suitability for automated SMT assembly.

Technical Context

The 74LVTH32245G implements four independent 8-bit transceiver bytes, each with dedicated T/Rn and OEn control pins-enabling selective bidirectional data flow between A- and B-side buses. Its bushold circuitry actively maintains last-valid logic state on un-driven inputs, eliminating external biasing components.

It uses advanced BiCMOS fabrication to achieve propagation delays as low as 1.3 ns (tPHL, VCC = 3.3 V) while maintaining low ICCZ (0.19 mA per supply rail when outputs disabled). Dual VCC domains isolate power delivery to Byte pairs, reducing simultaneous switching noise and supporting mixed-voltage domain bridging.

Key Specifications

Pinout & Package

Package: 96-ball Fine-Pitch Ball Grid Array (FBGA), JEDEC MO-205, 5.5 mm × 5.5 mm body, 0.8 mm ball pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVT8245A and 74ALVCH32245, the 74LVTH32245G uniquely combines byte-selectable control, bushold, 5 V I/O tolerance, and FBGA packaging-making it optimal for high-density, mixed-voltage, hot-pluggable systems requiring per-byte bus management.

Availability

74LVTH32245G is available at Aetrix Electronics and suitable for telecom backplane interfaces, industrial PLC I/O expansion, server memory subsystem bridges, and test equipment bus adapters requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for 74LVTH32245G 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

Fairchild Semiconductor was a U.S.-based analog and power IC manufacturer, acquired by ON Semiconductor in 2016; its legacy logic portfolio remains widely deployed in industrial and infrastructure systems.

The 74LVTH32245G belongs to Fairchild's LVT/LVTH low-voltage BiCMOS transceiver family, designed specifically for high-speed, low-power bridging between 3.3 V logic domains and 5 V legacy buses in telecom, computing, and automation equipment.

FAQ

What is the function of the bushold feature in the 74LVTH32245G?

The bushold feature in the 74LVTH32245G actively retains the last valid logic state on any undriven A- or B-side input pin, eliminating the need for external pull-up or pull-down resistors. This reduces component count, saves PCB area, and improves reliability during hot-insertion events. The 74LVTH32245G specifies ±75 µA minimum bushold drive current at VI = 0.8 V/2.0 V, ensuring robust state retention across temperature and voltage extremes.

Can the 74LVTH32245G operate with only one VCC rail powered?

No-the 74LVTH32245G requires both VCC1 and VCC2 to be properly decoupled and powered within 2.7–3.6 V for functional operation. VCC1 supplies Bytes 1–2 (A0–A15/B0–B15), and VCC2 supplies Bytes 3–4 (A16–A31/B16–B31). Leaving either rail unpowered may cause undefined output states, increased leakage, or latch-up risk. The datasheet explicitly defines separate ICCZ and ICCL values per rail, confirming independent power domain design.

How does the 74LVTH32245G handle direction control for individual bytes?

The 74LVTH32245G provides four independent T/R inputs (T/R1–T/R4), each controlling the data flow direction for its associated 8-bit byte pair: T/R1 governs A0–A7 ↔ B0–B7, T/R2 for A8–A15 ↔ B8–B15, and so on. Direction is active per byte regardless of OE state; when OE is HIGH, both ports enter high-impedance regardless of T/R value. This enables granular bus arbitration-for example, reading from B-side on Byte 1 while writing to B-side on Byte 3 simultaneously.

Is the 74LVTH32245G pin-compatible with the 74LVT32245G?

Yes-the 74LVTH32245G and 74LVT32245G share identical FBGA96A package, pinout, and electrical interface; the sole functional difference is the inclusion of bushold circuitry in the LVTH variant. All control (OEn, T/Rn) and data (A0–A31, B0–B31) pins map identically. No PCB layout change is needed when upgrading from 74LVT32245G to 74LVTH32245G, though firmware or system-level pull-up removal may be required to leverage bushold.

What is the maximum capacitive load the 74LVTH32245G can drive reliably?

The 74LVTH32245G is characterized for CL = 50 pF in AC timing specifications (e.g., tPLH, tPHL), and its output drive strength (±32 mA/±64 mA) supports heavier loads. Based on VOL/VOH specs at IOL = 64 mA (VOL ≤ 0.55 V) and IOH = −32 mA (VOH ≥ VCC − 0.2 V), the device can reliably drive ≥10 standard CMOS loads (≈10 pF each) or traces up to ≈8 cm (at 3.3 V, FR-4) before violating setup/hold margins. For >50 pF, verify timing with actual layout parasitics using the 74LVTH32245G's published dynamic VOLP/VOLV values.