Texas Instruments SN74LV138AQWBQBRQ1

Overview

SN74LV138AQWBQBRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive 3-line-to-8-line decoder/demultiplexer with 2 V to 5.5 V V_CC operation, 9.5 ns max propagation delay at 5 V, I_off partial-power-down support, and active-low G0/G1 plus active-high G2 enable architecture. It serves as a memory address decoder or data routing switch in engine control units and body electronics modules.

For engineers reviewing the SN74LV138AQWBQBRQ1 datasheet, SN74LV138AQWBQBRQ1 pinout, SN74LV138AQWBQBRQ1 application, or SN74LV138AQWBQBRQ1 equivalent, key selection criteria include automotive temperature range (–40°C to +125°C), mixed-mode voltage compatibility across all ports, output ground bounce <0.8 V at 3.3 V, and WQFN-16 (BQB) package thermal performance (R_θJA = 86°C/W).

Technical Context

The SN74LV138AQWBQBRQ1 implements a positive-logic 3:8 decoder with three binary-select inputs (A0–A2) and three enable inputs (G2 high-active, G0/G1 low-active), enabling direct cascading without external inverters. Its CMOS push-pull outputs drive up to ±12 mA at 5 V while maintaining VOL ≤ 0.55 V and VOH ≥ 3.8 V under load.

Designed for automotive memory decoding and data routing, it features I_off circuitry that disables outputs during power-down to prevent backflow current, and supports stable operation with capacitive loads ≤50 pF. The device meets AEC-Q100-002 HBM Level 2 (±2 kV) and AEC-Q100-011 CDM Level C4B (±1 kV) ESD requirements.

Key Specifications

Pinout & Package

SN74LV138AQWBQBRQ1 uses a 16-pin WQFN package (BQB) with 3.60 mm × 2.60 mm body size and wettable flanks for AOI-compatible solder joint inspection. Thermal pad (exposed die attach) enhances thermal dissipation (R_θJB = 54.9°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-to-8 decoder applications.

Compared with SN74HC138QPWRQ1 and MC74LVX138DT, SN74LV138AQWBQBRQ1 uniquely combines Grade 1 temperature range, I_off protection, and 9.5 ns speed in a thermally optimized WQFN package - making it the only option qualified for high-reliability automotive decoding where power-domain isolation and timing integrity are mandatory.

Availability

SN74LV138AQWBQBRQ1 is available at Aetrix Electronics and suitable for engine control units, instrument cluster displays, and body control modules requiring stable component supply across extended automotive lifecycles.

Supply support for SN74LV138AQWBQBRQ1 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 SN74LV138AQWBQBRQ1 belongs to TI's LV-A family of automotive-qualified logic devices, engineered specifically for low-voltage, high-speed decoding and demultiplexing in safety-critical vehicle subsystems.

FAQ

What is the maximum operating temperature for SN74LV138AQWBQBRQ1?

The SN74LV138AQWBQBRQ1 is rated for continuous operation from –40°C to +125°C ambient temperature (AEC-Q100 Grade 1). This specification is validated across process corners and lifetime stress conditions, making SN74LV138AQWBQBRQ1 suitable for under-hood applications such as transmission control modules and battery management systems where junction temperatures may exceed 150°C under transient load.

Does SN74LV138AQWBQBRQ1 support partial power-down mode?

Yes, SN74LV138AQWBQBRQ1 includes I_off circuitry that disables all outputs when V_CC = 0 V, limiting leakage to <5 μA per terminal. This feature prevents back-current flow from powered sections into unpowered domains - a critical requirement in modern automotive domain controllers with independent power rails. The I_off behavior is specified across full temperature range and verified per JESD78.

What is the propagation delay of SN74LV138AQWBQBRQ1 at 3.3 V supply?

At V_CC = 3.3 V and CL = 15 pF, the typical propagation delay (t_pd) of SN74LV138AQWBQBRQ1 is 11.4 ns, with a maximum of 13.5 ns over temperature and voltage extremes. This value applies to transitions from any address input (A0–A2) or enable input (G0/G1/G2) to any output (Y0–Y7), as confirmed in Section 6.7 of the official datasheet SCLS885.

Can SN74LV138AQWBQBRQ1 interface with both 3.3 V and 5 V logic families?

Yes, SN74LV138AQWBQBRQ1 supports mixed-mode voltage operation: its inputs tolerate 0–5.5 V regardless of V_CC, and outputs swing rail-to-rail (VOL ≈ 0 V, VOH ≈ V_CC). When powered at 3.3 V, it can accept 5 V inputs without damage and drive 3.3 V CMOS loads; when powered at 5 V, it drives 5 V TTL/CMOS loads while accepting 3.3 V control signals - eliminating external level shifters in heterogeneous systems.

Is SN74LV138AQWBQBRQ1 pin-compatible with standard SN74LV138A devices?

Yes, SN74LV138AQWBQBRQ1 shares identical pin configuration, function mapping, and electrical behavior with commercial-grade SN74LV138A in the same BQB (WQFN-16) package. Pin-for-pin compatibility extends to signal names (A0–A2, G0–G2, Y0–Y7, V_CC, GND), thermal pad placement, and PCB footprint - enabling drop-in replacement in existing designs upgraded to automotive qualification.