onsemi 74LCXH16245G

Overview

74LCXH16245G from Fairchild Semiconductor is a low-voltage 16-bit bidirectional transceiver with bushold inputs, designed for bus interface between 2.5V/3.3V domains and 5V signal environments. It features dual-byte control (OE1/T/R1 and OE2/T/R2), 3-STATE outputs, 4.5 ns max propagation delay at VCC = 3.3V, ±24 mA output drive at VCC = 3.0V, and eliminates external pull-up resistors via active bushold circuitry. It is used in memory expansion, processor local bus bridging, and mixed-voltage backplane interconnects.

For engineers reviewing the 74LCXH16245G datasheet, pinout, applications, or equivalent options, key selection considerations include bidirectional byte control logic, bushold input retention without external biasing, 54-ball FBGA package compatibility, and 2.3V–3.6V supply operation with 5V-tolerant I/O.

Technical Context

The 74LCXH16245G implements two independent 8-bit transceiver sections-A0–A7/B0–B7 controlled by OE1/T/R1, and A8–A15/B8–B15 controlled by OE2/T/R2-enabling flexible data flow direction per byte. Each section supports high-impedance 3-STATE outputs and bushold on all A/B port inputs, ensuring stable logic levels on floating or unused lines without external components.

It operates across 2.3V–3.6V VCC with guaranteed AC performance down to 2.3V, including 4.5 ns max tPHL/tPLH at 3.3V and 5.4 ns at 2.5V. The device conforms to JESD78 latch-up requirements and achieves 2000V HBM ESD rating, targeting robustness in industrial and computing bus systems.

Key Specifications

Pinout & Package

74LCXH16245G is packaged in a 54-ball Fine-Pitch Ball Grid Array (FBGA), JEDEC MO-205 compliant, 5.5 mm × 5.5 mm body size, with 0.8 mm ball pitch. Pin assignments are defined for top-thru view per datasheet Figure 2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74LCXH16245G, the 74ALVC16245Q offers faster timing but increases component count and layout complexity, while the SN74LVC16245ADGGR trades bushold and 5V tolerance for package familiarity-neither provides drop-in replacement capability without design revision.

Availability

74LCXH16245G is available at Aetrix Electronics and suitable for memory expansion interfaces, processor local bus bridges, and mixed-voltage backplane interconnects requiring stable component supply, long-term lifecycle support, and consistent FBGA packaging.

Supply support for 74LCXH16245G 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 semiconductor company specializing in power management, analog, and logic ICs before its acquisition by ON Semiconductor in 2016; its legacy logic families remain widely deployed in industrial and computing systems.

The 74LCXH16245G belongs to the LCXH low-voltage high-speed logic family, engineered specifically for mixed-voltage bus interfacing in space-constrained, noise-sensitive applications such as embedded controllers and communications infrastructure.

FAQ

What is the function of bushold in the 74LCXH16245G?

The bushold circuitry in the 74LCXH16245G actively holds floating or unused A/B port inputs at their last-valid logic state without external pull-up or pull-down resistors. This feature prevents undefined logic levels during power-up, partial bus disable, or hot-swap events, directly reducing BOM cost and PCB area. The 74LCXH16245G specifies minimum bushold drive current of 45 µA at VCC = 2.3V, ensuring reliable retention across its full operating voltage range.

Does the 74LCXH16245G support true 5V-tolerant I/O?

Yes, the 74LCXH16245G supports 5V-tolerant inputs and outputs while operating from a 2.3V–3.6V VCC supply. Its absolute maximum input voltage rating is 7.0V, and DC electrical characteristics confirm valid operation with VI up to VCC + 0.5V and VO up to 7.0V in 3-STATE mode. This enables direct connection to 5V peripherals without level-shifting circuitry - a verified capability documented in the "Recommended Operating Conditions" and "Absolute Maximum Ratings" tables of the 74LCXH16245G datasheet.

What is the pin configuration difference between 74LCXH16245G and 74LCXH16245MTD?

The 74LCXH16245G uses a 54-ball FBGA (BGA54A) package with 0.8 mm pitch and top-thru pin assignment, while the 74LCXH16245MTD uses a 48-lead TSSOP (MTD48) package with gull-wing leads and JEDEC MO-153 outline. Their pinouts are incompatible: FBGA has dedicated VCC/GND balls distributed across the array, whereas TSSOP places power/ground on perimeter pins. The 74LCXH16245G cannot be substituted for 74LCXH16245MTD without PCB redesign due to mechanical and routing incompatibility.

Can the 74LCXH16245G operate at 2.5V supply?

Yes, the 74LCXH16245G is fully specified for 2.5V ±0.2V operation, with AC timing parameters guaranteed at CL = 30 pF: tPHL/tPLH ≤5.4 ns, tPZL/tPZH ≤8.5 ns, and tPLZ/tPHZ ≤7.7 ns. DC characteristics including VIH/VIL thresholds, VOL/VOH levels, and bushold current are also validated across 2.3V–3.6V, confirming robust functionality at 2.5V - a key requirement for low-power embedded systems where the 74LCXH16245G is commonly deployed.

Is the 74LCXH16245G pin-compatible with standard 74LVC16245 devices?

No, the 74LCXH16245G is not pin-compatible with standard 74LVC16245 variants. While both are 16-bit bidirectional transceivers, the 74LCXH16245G's 54-ball FBGA package (BGA54A) has a unique pin map optimized for low-inductance power delivery and signal integrity - differing fundamentally from the 48-pin TSSOP or SOIC packages used by LVC-series equivalents. Even functionally identical pins (e.g., OE1, T/R1) occupy different physical locations, making direct substitution impossible without PCB modification.