Texas Instruments SN74HCS245QWRKSRQ1

Overview

SN74HCS245QWRKSRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive octal bus transceiver with 3-state outputs and Schmitt-trigger inputs, operating from 2 V to 6 V supply. It features ±7.8-mA output drive at 6 V, typical ICC of 100 nA, and hysteresis (ΔVT) up to 1.6 V for noise immunity-used in vehicle body control modules to isolate bidirectional data buses between microcontrollers and peripheral sensors.

For engineers reviewing the SN74HCS245QWRKSRQ1 datasheet, SN74HCS245QWRKSRQ1 pinout, SN74HCS245QWRKSRQ1 application, or SN74HCS245QWRKSRQ1 equivalent, key selection criteria include automotive temperature range (–40°C to +125°C), wettable-flank VQFN-20 package compatibility with AOI inspection, Schmitt-trigger input noise rejection, and direction-controlled bidirectional data flow in CAN/LIN subsystems.

Technical Context

The SN74HCS245QWRKSRQ1 implements eight independent CMOS transceivers, each with dual-directional buffers (A↔B) controlled by a shared DIR pin and globally enabled/disabled via active-low OE. Its Schmitt-trigger inputs provide hysteresis (ΔVT = 0.6–1.6 V) to reject slow-edge or noisy signals without external conditioning.

All outputs support true 3-state operation with balanced sourcing/sinking capability (±7.8 mA at 6 V), low leakage (±100 nA), and propagation delays as low as 7 ns at 6 V. The device uses standard CMOS logic thresholds referenced to VCC and maintains high-impedance state during power-up when OE is pulled high.

Key Specifications

Pinout & Package

The SN74HCS245QWRKSRQ1 is housed in a 4.50 mm × 2.50 mm wettable-flank VQFN-20 package (WRKS), optimized for automated optical inspection (AOI) and thermal performance (R_θJA = 75.6°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCS245PWQ1 and MC74VHC245DTG, the SN74HCS245QWRKSRQ1 uniquely combines AEC-Q100 Grade 1 qualification, wettable-flank packaging for automated manufacturing, and industry-leading Schmitt-trigger hysteresis - making it the sole option for safety-critical, high-volume automotive bus isolation where zero-defect assembly and EMI resilience are mandatory.

Availability

SN74HCS245QWRKSRQ1 is available at Aetrix Electronics and suitable for automotive body control modules, infotainment system interconnects, and ADAS camera interface designs requiring stable component supply across extended temperature ranges and full AEC-Q100 compliance.

Supply support for SN74HCS245QWRKSRQ1 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 delivering analog and embedded processing solutions for automotive, industrial, and personal electronics markets.

The SN74HCS245QWRKSRQ1 belongs to TI's automotive-qualified HCS logic family, designed specifically for noise-immune, low-power bidirectional data routing in harsh-EMI vehicle environments.

FAQ

What is the maximum capacitive load the SN74HCS245QWRKSRQ1 can drive while meeting all datasheet specifications?

The SN74HCS245QWRKSRQ1 is specified to drive loads ≤50 pF while maintaining guaranteed switching characteristics and output voltage levels. Driving larger capacitances increases propagation delay and may degrade VOL/VOH margins - especially at 2 V supply. For >50-pF loads, add series damping resistors or verify timing margins in final layout. The SN74HCS245QWRKSRQ1 datasheet explicitly states this 50-pF limit in Section 9.2.1.1.

Does the SN74HCS245QWRKSRQ1 require external pull-up resistors on unused inputs?

Yes - unused inputs on the SN74HCS245QWRKSRQ1 must be terminated to either VCC or GND to prevent floating nodes that cause excessive current draw and logic instability. A 10-kΩ pull-up or pull-down resistor is recommended per TI's guidance in Section 9.2.1.2. Leaving inputs unconnected violates the Absolute Maximum Ratings and risks latch-up or increased ICC in the SN74HCS245QWRKSRQ1.

How does the Schmitt-trigger input hysteresis of the SN74HCS245QWRKSRQ1 improve noise immunity in automotive applications?

The SN74HCS245QWRKSRQ1 provides input hysteresis (ΔVT) ranging from 0.6 V to 1.6 V depending on supply voltage - meaning noise spikes must exceed this peak-to-peak amplitude to cause false logic transitions. This allows reliable interfacing with slow-switching sensors (e.g., door latch switches) and noisy harnesses without external filtering. The SN74HCS245QWRKSRQ1's hysteresis is explicitly characterized in Table 6.5 and enables direct connection to unconditioned automotive signals.

Can multiple channels of the SN74HCS245QWRKSRQ1 be paralleled to increase output drive strength?

Yes - the SN74HCS245QWRKSRQ1 allows paralleling of identical channels (e.g., A1+B1) to double output current capability, as confirmed in Section 9.2.1.3. This is valid only when both channels share identical DIR and OE states and drive the same net. Paralleling increases effective drive to ±15.6 mA at 6 V but requires matched trace lengths to avoid skew. This technique is documented for the SN74HCS245QWRKSRQ1 in its official application guidance.

What is the purpose of the thermal pad on the bottom of the SN74HCS245QWRKSRQ1 WRKS package?

The exposed thermal pad on the SN74HCS245QWRKSRQ1 WRKS package serves two functions: improving thermal dissipation (R_θJB = 49.6°C/W) and enhancing solder joint reliability via wettable flanks for AOI. TI specifies in Section 5 that the pad may be connected to GND or left floating - but never tied to any other signal or supply. Proper pad connection reduces junction temperature rise during sustained 7.8-mA output loading, directly extending lifetime in automotive under-hood applications.