Texas Instruments SN74AHC245QDWRG4

Overview

SN74AHC245QDWRG4 from Texas Instruments is an automotive-grade octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between two 8-bit buses. It operates from 2 V to 5.5 V, supports –40°C to 125°C ambient temperature, delivers ±8 mA output drive at 5 V, and features propagation delays as low as 4 ns (VCC = 5 V, CL = 15 pF). It is used in automotive infotainment backplane interfaces requiring voltage-level flexible, isolated bus communication.

For engineers reviewing the SN74AHC245QDWRG4 datasheet, SN74AHC245QDWRG4 pinout, SN74AHC245QDWRG4 application, or SN74AHC245QDWRG4 equivalent, key selection criteria include direction-control logic behavior, 3-state isolation timing (tPZH/tPLZ ≤ 9.2 ns), automotive AEC-Q100 qualification status, SOIC-20 thermal performance (θJA = 58°C/W), and compatibility with mixed-voltage 2.0–5.5 V system domains.

Technical Context

This device implements dual-rail 8-channel bidirectional data routing controlled by DIR (direction) and OE (output enable) inputs. Its CMOS AHC logic family ensures rail-to-rail input thresholds (VIH/VIL track VCC), low dynamic power (Cpd = 14 pF), and robust latch-up immunity (>250 mA per JESD 17). The 3-state outputs provide high-impedance isolation when OE is high, enabling bus sharing without contention.

It uses positive-logic control: DIR = L enables B→A transfer; DIR = H enables A→B transfer; OE = H forces all outputs into high-Z. Input transition rate limits (20 ns/V at 5 V) and noise immunity specs (VIL(D) = 1.5 V, VOH(V) = 4.3 V) are defined for stable operation in electrically noisy automotive environments.

Key Specifications

Pinout & Package

SN74AHC245QDWRG4 is housed in a 20-pin SOIC (DW) package, 7.5 mm × 12.8 mm body, 2.65 mm max height, 1.27 mm pitch, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHC245QDWRG4, SN74LVC245AQPWRQ1 offers superior speed and drive strength but sacrifices 2 V operation, while SN74AHCT245QPWR provides seamless TTL input compatibility at the cost of slightly higher ICC - both require validation of timing margins in high-noise environments.

Availability

SN74AHC245QDWRG4 is available at Aetrix Electronics and suitable for automotive infotainment backplanes, industrial PLC I/O modules, and ADAS camera sensor interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74AHC245QDWRG4 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 automotive electronics, with decades of experience in high-reliability industrial and automotive solutions.

The SN74AHC245Q series belongs to TI's automotive-qualified logic portfolio, engineered specifically for robust bidirectional data routing in harsh-temperature vehicle subsystems where voltage flexibility and bus isolation are critical.

FAQ

What is the maximum clock frequency supported by SN74AHC245QDWRG4 in a data bus application?

SN74AHC245QDWRG4 does not operate on a clock; it is an asynchronous transceiver. Its usable data rate depends on propagation delay and load capacitance. At VCC = 5 V and CL = 15 pF, tPLH/tPHL ≤ 6.5 ns supports reliable toggling up to ~75 MHz (1/(2 × 6.5 ns)) in point-to-point configurations. For bus topologies, trace length and stub loading must be modeled using the 4 ns min delay and 14 pF Cpd value.

Does SN74AHC245QDWRG4 require external pull-up resistors on DIR or OE pins?

SN74AHC245QDWRG4 does not require pull-ups on DIR for basic operation, but OE must be actively driven or pulled up to VCC during power-up to ensure outputs remain in high-impedance state. TI recommends a pull-up resistor ≤10 kΩ on OE if no active driver is present - minimum value determined by the current-sinking capability of the controlling driver, per datasheet Section 1.

Is SN74AHC245QDWRG4 pin-compatible with standard SN74AHC245 devices?

Yes, SN74AHC245QDWRG4 shares identical pinout, electrical characteristics, and functional behavior with non-automotive SN74AHC245 variants in SOIC-DW package, including SN74AHC245DWR. Differences are limited to qualification level (Q1 vs commercial), marking (AHC245Q1), and packaging compliance (AEC-Q100 stress test reporting), not physical or logical interface.

Can SN74AHC245QDWRG4 interface between 2.5 V and 5 V buses without level-shifting components?

Yes, SN74AHC245QDWRG4 supports mixed-voltage operation: its inputs tolerate 0–5.5 V regardless of VCC, and outputs swing rail-to-rail. When VCC = 2.5 V, it accepts 5 V inputs safely (VI ≤ 7 V absolute max) and drives 2.5 V logic levels; when VCC = 5 V, it drives full 5 V outputs while accepting 2.5 V inputs (VIH = 1.65 V min at VCC = 5 V). No external level shifters are needed.

What is the meaning of "G4" and "Q1.A" suffixes in SN74AHC245QDWRG4Q1.A?

The "G4" denotes green (lead-free, RoHS-compliant) packaging per TI's standard nomenclature; "Q1" indicates automotive qualification grade; and ".A" is TI's internal revision identifier for manufacturing lot control and traceability. All three suffixes appear in the official orderable part number SN74AHC245QDWRG4Q1.A and confirm full AEC-Q100 compliance, NIPDAU finish, and MSL Level-1 handling.