Texas Instruments SN74LVCH245AZQNR

Overview

SN74LVCH245AZQNR from Texas Instruments is an octal bus transceiver with tri-state outputs, designed for 1.65 V to 3.6 V operation and supporting mixed-mode 5-V input/3.3-V V_CC signal translation. It features 20-pin MICROSTAR JUNIOR BGA packaging (4.00 mm × 3.00 mm), bus-hold on all data inputs, I_off for live insertion, and a max propagation delay of 6.3 ns at 3.3 V. It enables bidirectional data flow between A and B buses in server memory interfaces.

For engineers reviewing the SN74LVCH245AZQNR datasheet, SN74LVCH245AZQNR pinout, SN74LVCH245AZQNR application, or SN74LVCH245AZQNR equivalent, this page delivers verified electrical specs, validated ZQN-package pin mapping, real-world use cases in high-density computing systems, and two confirmed alternative transceivers with documented functional and thermal differences.

Technical Context

The SN74LVCH245AZQNR implements a direction-controlled, tri-stateable 8-bit bidirectional data path using balanced CMOS push-pull outputs capable of ±24 mA drive at 3.0 V. Its I_off circuitry actively isolates I/O terminals during partial power-down, preventing back-drive current when V_CC = 0 V.

Bus-hold circuitry maintains valid logic states on floating A/B port inputs without external resistors, and input tolerance up to 5.5 V allows direct interfacing with legacy 5-V logic while operating from a 1.65–3.6 V supply - critical for voltage-level bridging in heterogeneous digital subsystems.

Key Specifications

Pinout & Package

SN74LVCH245AZQNR uses a 20-ball MICROSTAR JUNIOR BGA (ZQN) package with 0.5-mm pitch and 4.00 mm × 3.00 mm body size. The package is lead-free, RoHS-compliant, and optimized for high-density PCB layouts in space-constrained applications such as server DIMM modules and compact networking hardware.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245AQPWRQ1 and SN74AVC245ZRGR, SN74LVCH245AZQNR uniquely combines bus-hold, I_off, and 5-V-tolerant inputs in the compact ZQN BGA - making it optimal for space-constrained, hot-pluggable industrial compute modules where BOM simplification and robust power sequencing are critical.

Availability

SN74LVCH245AZQNR is available at Aetrix Electronics and suitable for server memory interconnects, industrial PLC backplanes, and network switch fabric interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVCH245AZQNR 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 specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The SN74LVCH245A product line delivers robust, low-voltage octal transceivers engineered for mixed-signal voltage translation and hot-swap-capable bus isolation in high-reliability computing infrastructure.

FAQ

What is the maximum operating temperature for SN74LVCH245AZQNR?

The SN74LVCH245AZQNR is rated for continuous operation from –40°C to +125°C ambient temperature, as specified in the Recommended Operating Conditions table of the official TI datasheet SCES008Q. This extended range supports deployment in telecom base stations, industrial controllers, and automotive under-hood applications where thermal management is constrained. The ZQN package's R_θJA of 129.3°C/W requires careful attention to PCB copper area and airflow in high-ambient scenarios.

Does SN74LVCH245AZQNR support 5-V input signals while powered at 1.8 V?

Yes, SN74LVCH245AZQNR supports input voltages up to 5.5 V regardless of V_CC level - including at 1.8 V operation - enabling true mixed-voltage translation. This is achieved via internal clamp diodes and robust input structure, as confirmed in Section 6.1 (Absolute Maximum Ratings) and Section 6.3 (Recommended Operating Conditions) of the TI datasheet. No external level shifters are needed when interfacing with legacy 5-V peripherals.

How does the bus-hold feature work on SN74LVCH245AZQNR?

The bus-hold circuitry on SN74LVCH245AZQNR actively maintains the last-valid logic state on each A/B port input (A1–A8, B1–B8) when left floating, using ±75 µA hold current at 3.0 V. As described in Section 8.1 and Table 6.6, this eliminates external pull-up/pull-down resistors. Bus-hold remains active regardless of OE or DIR state and cannot be disabled - making it ideal for systems with undriven test points or unpopulated slots.

Is SN74LVCH245AZQNR pin-compatible with other SN74LVCH245A package variants?

No - SN74LVCH245AZQNR uses the 20-ball MICROSTAR JUNIOR (ZQN) BGA footprint, which is physically and electrically distinct from SSOP, TSSOP, SOIC, or VQFN variants. Pin assignments differ significantly (e.g., DIR on Ball A2, V_CC on Ball B2 per ZQN pin map), and solder reflow profiles are BGA-specific. Migration requires full PCB redesign; it is not a drop-in replacement for DB, PW, or RGY packages.

What is the typical power dissipation of SN74LVCH245AZQNR at 3.3 V with all outputs enabled?

At V_CC = 3.3 V and TA = 25°C, SN74LVCH245AZQNR exhibits a typical power dissipation capacitance (C_pd) of 47 pF per transceiver with outputs enabled, as stated in Section 6.11. With all eight channels active at 10 MHz, total dynamic power is approximately 5.1 mW (calculated as C_pd × V_CC² × f). Quiescent ICC is just 10 µA, making it suitable for low-power always-on subsystems.