onsemi 74LVTH2245MTCX

Overview

74LVTH2245MTCX from onsemi is a low-voltage octal bidirectional transceiver with 3-STATE inputs/outputs, bushold inputs on all data pins, and integrated 25Ω series resistors on B-port outputs. It operates at 2.7–3.6V V_CC, supports 5V-tolerant I/O, delivers ±64mA drive on A port and ±12mA on B port, and is qualified for industrial temperature range (–40°C to +85°C). It enables level-shifting and bus isolation in mixed-voltage backplane or motherboard interconnects.

For engineers reviewing the 74LVTH2245MTCX datasheet, pinout, applications, or equivalent options, key selection criteria include bushold-enabled input retention, B-port output impedance control, A/B port current asymmetry, live insertion capability, and TSSOP-20 package compatibility with high-density PCB layouts.

Technical Context

The 74LVTH2245MTCX implements eight non-inverting bidirectional buffers controlled by separate OE (active-HIGH disable) and T/R (active-HIGH transmit) inputs. Data direction flows A→B when T/R = HIGH and B→A when T/R = LOW; both ports enter high-impedance state when OE = HIGH.

Bushold circuitry actively holds unused data inputs at their last valid logic state without external pull-ups, while the built-in 25Ω series resistor on each B-port output reduces switching overshoot/undershoot and improves signal integrity on stub-loaded buses.

Key Specifications

Pinout & Package

74LVTH2245MTCX uses a 20-lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 compliant, 4.4mm body width, 0.65mm lead pitch, and exposed pad not present. Pin numbering follows standard dual-inline counterclockwise convention starting from pin 1 (OE) at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC2245APW and 74ALVCH162245QNR, the 74LVTH2245MTCX uniquely combines bushold, 5V-tolerant I/O, and B-port 25Ω series resistors in a compact TSSOP-20 package-reducing component count, simplifying layout, and improving signal integrity for industrial bus interfaces without requiring redesign.

Availability

74LVTH2245MTCX is available at Aetrix Electronics and suitable for industrial backplane interconnects, hot-swappable module interfaces, and embedded memory expansion buses requiring stable component supply across extended product lifecycles.

Supply support for 74LVTH2245MTCX 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

onsemi (formerly Fairchild Semiconductor) is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The 74LVTH2245MTCX belongs to the LVT/LVTH logic family designed specifically for high-speed, low-voltage bus interface applications where mixed-voltage interoperability, signal integrity, and robustness during live insertion are critical.

FAQ

What is the function of the bushold feature in the 74LVTH2245MTCX?

The bushold feature in the 74LVTH2245MTCX actively maintains the last valid logic state on all data inputs (A0–A7 and B0–B7) when those pins are left unconnected or float during system initialization or hot-swap events. This eliminates the need for external pull-up or pull-down resistors, reducing bill-of-materials cost and PCB real estate. The 74LVTH2245MTCX specifies ±75µA minimum hold current at 0.8V/2.0V input levels, ensuring reliable state retention across its full operating temperature range.

Does the 74LVTH2245MTCX support 5V logic interfacing?

Yes, the 74LVTH2245MTCX supports 5V-tolerant inputs: its data and control pins (A0–A7, B0–B7, OE, T/R) accept DC input voltages from 0V to 5.5V while operating from a 2.7–3.6V V_CC supply. This allows direct connection to 5V CMOS or TTL devices without level-shifting circuitry. However, output voltages remain bounded by V_CC, so B-port outputs swing from 0V to V_CC (not 5V), making them compatible with 5V inputs but not 5V outputs.

What is the purpose of the 25Ω series resistors on the B port of the 74LVTH2245MTCX?

The 25Ω series resistors integrated into each B-port output (B0–B7) of the 74LVTH2245MTCX serve to dampen signal reflections and reduce overshoot/undershoot on transmission lines, particularly in unterminated or stub-loaded bus configurations. This improves signal integrity and EMI performance without requiring discrete surface-mount resistors. The 74LVTH2245MTCX datasheet confirms this value is process-trimmed and effective across its full operating voltage and temperature range.

Can the 74LVTH2245MTCX be used in hot-swap applications?

Yes, the 74LVTH2245MTCX supports live insertion and extraction due to its power-up/power-down high-impedance behavior: both A and B ports enter a high-Z state during V_CC ramp-up or ramp-down, preventing bus contention or glitch generation when modules are inserted or removed under power. This feature is explicitly validated in the datasheet and makes the 74LVTH2245MTCX suitable for telecom line cards, modular servers, and industrial PLC backplanes requiring hot-swap capability.

Is the 74LVTH2245MTCX still recommended for new designs?

No-the 74LVTH2245MTCX is marked "DISCONTINUED" and "NOT RECOMMENDED FOR NEW DESIGN" in the official onsemi datasheet revision 1.5.0. While Aetrix Electronics maintains inventory for legacy system support and repair, engineers designing new products should consult onsemi's current portfolio for modern alternatives with enhanced features, longer lifecycle assurance, and full technical support. The 74LVTH2245MTCX remains fully functional and specification-compliant for existing applications.