Texas Instruments CAHC1G126QDBVRQ1

Overview

CAHC1G126QDBVRQ1 from Texas Instruments is an automotive-qualified single 3-state bus buffer gate with integrated voltage translation, performing Y = A in positive logic. It operates from 2 V to 5.5 V, delivers ±8 mA output drive at 5 V, consumes ≤10 µA ICC, and supports -40°C to +125°C ambient operation for engine control and body electronics signal routing.

For engineers reviewing the CAHC1G126QDBVRQ1 datasheet, CAHC1G126QDBVRQ1 pinout, CAHC1G126QDBVRQ1 application, or CAHC1G126QDBVRQ1 equivalent, key selection criteria include AEC-Q100 Grade 1 qualification, SOT-23 (DBV) package compatibility, 3-state enable timing (tPLZ/tPHZ ≤ 12.5 ns @ 5 V), and CMOS input/output level translation across 1.8–5 V domains.

Technical Context

This device implements a single non-inverting buffer with active-high 3-state output control (OE), enabling bidirectional bus isolation in automotive networks. Its standard CMOS inputs require fast transitions (≤20 ns/V at 5 V) to prevent oscillation, and its balanced CMOS outputs support symmetrical sourcing/sinking up to ±8 mA at 5 V with defined VOL ≤ 0.44 V and VOH ≥ 3.8 V.

The IC integrates voltage translation by referencing all I/O levels to VCC - allowing interface between 1.8-V, 2.5-V, 3.3-V, and 5-V logic domains without external level shifters. Its latch-up immunity (>250 mA per JESD17) and AEC-Q100 HBM/CDM ESD ratings (Level 2 / C4B) ensure robustness in noisy vehicle environments.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.9 mm × 2.8 mm footprint, 1.6 mm body height, thermally enhanced for automotive PCBs with RθJA = 278 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G126QDBVRQ1, CAHC1G126QDBVRQ1 provides guaranteed -40°C to +125°C operation and tighter ESD specs but lower drive strength; versus MC74VHC1GT126DTT1G, it offers faster enable timing and TI-specific packaging consistency, though pinout differs.

Availability

CAHC1G126QDBVRQ1 is available at Aetrix Electronics and suitable for engine control units, body control modules, transmission control systems, and infotainment interfaces requiring stable component supply across automotive production lifecycles.

Supply support for CAHC1G126QDBVRQ1 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 SN74AHC1G126-Q1 belongs to TI's automotive logic portfolio, designed specifically for signal conditioning, bus isolation, and voltage-level translation in safety-critical vehicle subsystems operating across extended temperature ranges.

FAQ

What is the maximum capacitive load supported by CAHC1G126QDBVRQ1 while maintaining specified timing?

CAHC1G126QDBVRQ1 maintains all datasheet timing specifications up to 50 pF load capacitance. At CL = 50 pF and VCC = 5 V, tPHL/tPLH remains ≤9.5 ns and tPLZ/tPHZ ≤11 ns. Exceeding 50 pF increases propagation delay and may degrade edge integrity; for heavier loads, add series resistance or consider buffer fanout staging. The device's 14 pF CPD and 3 pF CO values confirm optimized drive capability for typical PCB trace and IC input loading.

Does CAHC1G126QDBVRQ1 support true bidirectional data flow?

No, CAHC1G126QDBVRQ1 is a unidirectional buffer (Y = A) with 3-state output control. It does not support automatic direction sensing or dual-direction signal routing. For bidirectional applications like I²C or UART, external control logic must manage OE relative to data direction - e.g., asserting OE only when driving, deasserting when receiving. Its architecture lacks internal direction control or bus transceiver logic; use dedicated transceivers (e.g., SN74LVC245-Q1) for true bidirectional operation.

Can CAHC1G126QDBVRQ1 be used with 1.8-V input signals while powered from a 5-V supply?

Yes, CAHC1G126QDBVRQ1 supports voltage translation: 1.8-V inputs are valid when VCC = 5 V, as VIH(min) = 3.85 V and VIL(max) = 1.65 V at 5 V - meaning a 1.8-V HIGH signal falls below VIH(min) and would be interpreted as LOW. However, per TI's functional description, the device accepts 1.8-V, 2.5-V, 3.3-V, and 5-V CMOS levels *when referenced to VCC*. So with VCC = 5 V, it expects inputs near 0 V or 5 V. For true 1.8-V-to-5-V translation, use the device with VCC = 1.8 V (within 2–5.5 V range) and rely on its output swing to 1.8 V - not 5 V. True level shifting requires VCC matching the output domain.

What is the recommended bypass capacitor value and placement for CAHC1G126QDBVRQ1?

A 0.1-µF ceramic capacitor is recommended between VCC (Pin 5) and GND (Pin 3) for CAHC1G126QDBVRQ1, placed physically adjacent to the device with minimal trace length (<2 mm). This suppresses high-frequency supply noise generated during output switching. TI's layout example shows the capacitor mounted directly beside the SOT-23-5 body, with GND flood fill beneath. For systems with broadband noise, parallel a 1-µF capacitor nearby. Avoid vias in the capacitor path; use wide, short traces to maintain low ESL and ensure effective decoupling at >100 MHz.

How does the latch-up immunity of CAHC1G126QDBVRQ1 impact its use in automotive power domains?

CAHC1G126QDBVRQ1 exceeds 250 mA latch-up immunity per JESD17, enabling safe operation in automotive power domains subject to load dump (ISO 7637-2 Pulse 5a), ground bounce, or transient overcurrent. This rating ensures the device will not enter destructive high-current latch-up during 12-V/24-V system surges or ESD events - critical for engine bay and battery-connected modules. Unlike standard logic buffers, this immunity is validated under automotive stress conditions, eliminating need for external current-limiting resistors or protection ICs in most signal-path applications.