Diodes Incorporated 74LVCH245AQ20-13

Overview

74LVCH245AQ20-13 from Diodes Incorporated is an octal bus transceiver with bus hold and 3-state outputs, designed for bidirectional asynchronous data transfer between A and B buses in mixed-voltage systems. It operates from 1.65V to 3.6V, tolerates 5.5V inputs, supports partial power-down via IOFF, and delivers ±24mA drive at VCC = 3.0V - used in notebook I/O expansion and peripheral interface isolation.

For engineers reviewing the 74LVCH245AQ20-13 datasheet, 74LVCH245AQ20-13 pinout, 74LVCH245AQ20-13 application, or 74LVCH245AQ20-13 equivalent, key selection criteria include 3.3V/5V input compatibility, bus-hold functionality eliminating external resistors, low ground bounce (<0.8V), and QFN-20 thermal performance (θJA = 67°C/W).

Technical Context

The device implements dual-directional 8-bit data routing controlled by DIR and OE pins: DIR = H enables A→B transmission; DIR = L enables B→A transmission; OE = H forces all outputs into high-impedance state. Bus-hold circuitry actively maintains undriven inputs at valid logic levels without pull-up/down resistors.

IOFF protection disables output drivers during power-down, preventing back-current flow when VCC = 0V while inputs remain at 5.5V. All inputs feature Schmitt-trigger action for noise immunity, and output switching characteristics are specified across -40°C to +125°C with propagation delay as low as 3.8ns at 3.3V.

Key Specifications

Pinout & Package

V-QFN4525-20 package: 2.5mm × 4.5mm × 0.95mm body, 0.50mm lead pitch, exposed thermal pad (pin 20 = GND), JEDEC-compliant footprint per AP02001.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245APWR and 74AVC245BQX, the 74LVCH245AQ20-13 uniquely combines 5.5V-tolerant inputs, bus-hold, and IOFF in a thermally optimized QFN - making it the sole option for compact, mixed-voltage, hot-pluggable I/O interfaces.

Availability

74LVCH245AQ20-13 is available at Aetrix Electronics and suitable for PC notebook I/O expansion, SSD controller interface isolation, and industrial PLC I/O module data multiplexing requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for 74LVCH245AQ20-13 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, energy-efficient solutions for computing, consumer, and industrial markets.

The 74LVCH series targets low-voltage, mixed-signal interface applications - designed specifically for voltage translation, bus isolation, and power-aware system partitioning in space-constrained portable electronics.

FAQ

Can 74LVCH245AQ20-13 operate with VCC = 1.5V?

No. The absolute minimum recommended VCC is 1.65V per DS35891 Rev. 1–2. At 1.5V, parameters including VIH/VIL thresholds, output drive strength, and propagation delay fall outside specification - data retention mode (1.5V) applies only to static storage, not active operation.

Is the exposed thermal pad on pin 20 required to be soldered to GND?

Yes. The exposed pad (EP) is electrically connected to GND and serves as the primary thermal path. Diodes Incorporated's AP02001 pad layout specifies full-solder coverage to a solid GND plane; omitting this compromises thermal resistance (θJA degrades from 67°C/W to >100°C/W) and may cause premature thermal shutdown.

Does bus-hold functionality work when OE = HIGH?

Yes. Bus-hold remains active on all inputs regardless of OE state - it operates independently of output enable. When OE = HIGH, outputs are in high-impedance, but undriven A/B pins retain their last valid logic level via internal feedback, preventing metastability during bus arbitration.

What is the maximum capacitive load this device can drive reliably?

The datasheet specifies 50pF test load for switching characteristics. With 24mA drive capability and typical output capacitance of 5.5pF, the device reliably drives ≤30pF traces plus one standard CMOS input (≈10pF) - total ≤40pF. Exceeding this increases tPD and VOL/VOLP beyond guaranteed limits.